{
 "instance": {
  "fsbw-20220630x10q.htm": {
   "axisCustom": 1,
   "axisStandard": 32,
   "contextCount": 757,
   "dts": {
    "calculationLink": {
     "local": [
      "fsbw-20220630_cal.xml"
     ]
    },
    "definitionLink": {
     "local": [
      "fsbw-20220630_def.xml"
     ]
    },
    "inline": {
     "local": [
      "fsbw-20220630x10q.htm"
     ]
    },
    "labelLink": {
     "local": [
      "fsbw-20220630_lab.xml"
     ]
    },
    "presentationLink": {
     "local": [
      "fsbw-20220630_pre.xml"
     ]
    },
    "schema": {
     "local": [
      "fsbw-20220630.xsd"
     ],
     "remote": [
      "http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd",
      "http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd",
      "http://www.xbrl.org/2003/xl-2003-12-31.xsd",
      "http://www.xbrl.org/2003/xlink-2003-12-31.xsd",
      "http://www.xbrl.org/2005/xbrldt-2005.xsd",
      "http://www.xbrl.org/2006/ref-2006-02-27.xsd",
      "http://www.xbrl.org/lrr/arcrole/esma-arcrole-2018-11-21.xsd",
      "http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd",
      "http://www.xbrl.org/lrr/role/net-2009-12-16.xsd",
      "http://www.xbrl.org/lrr/role/reference-2009-12-16.xsd",
      "https://www.xbrl.org/2020/extensible-enumerations-2.0.xsd",
      "https://www.xbrl.org/dtr/type/2020-01-21/types.xsd",
      "https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd",
      "https://xbrl.fasb.org/srt/2021/elts/srt-roles-2021-01-31.xsd",
      "https://xbrl.fasb.org/srt/2021/elts/srt-types-2021-01-31.xsd",
      "https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd",
      "https://xbrl.fasb.org/us-gaap/2021/elts/us-roles-2021-01-31.xsd",
      "https://xbrl.fasb.org/us-gaap/2021/elts/us-types-2021-01-31.xsd",
      "https://xbrl.sec.gov/country/2021/country-2021.xsd",
      "https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd"
     ]
    }
   },
   "elementCount": 862,
   "entityCount": 1,
   "hidden": {
    "http://fasb.org/us-gaap/2021-01-31": 44,
    "http://www.fsbwa.com/20220630": 5,
    "http://xbrl.sec.gov/dei/2021q4": 8,
    "total": 57
   },
   "keyCustom": 117,
   "keyStandard": 446,
   "memberCustom": 36,
   "memberStandard": 69,
   "nsprefix": "fsbw",
   "nsuri": "http://www.fsbwa.com/20220630",
   "report": {
    "R1": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:DocumentType",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "document",
     "isDefault": "true",
     "longName": "00090 - Document - Document and Entity Information",
     "role": "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation",
     "shortName": "Document and Entity Information",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:DocumentType",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R10": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10201 - Disclosure - INVESTMENTS",
     "role": "http://www.fsbwa.com/role/DisclosureInvestments",
     "shortName": "INVESTMENTS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R11": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FinancingReceivablesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10301 - Disclosure - LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS",
     "role": "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoans",
     "shortName": "LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FinancingReceivablesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R12": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:TransfersAndServicingOfFinancialAssetsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10401 - Disclosure - SERVICING RIGHTS",
     "role": "http://www.fsbwa.com/role/DisclosureServicingRights",
     "shortName": "SERVICING RIGHTS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:TransfersAndServicingOfFinancialAssetsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R13": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10501 - Disclosure - DERIVATIVES",
     "role": "http://www.fsbwa.com/role/DisclosureDerivatives",
     "shortName": "DERIVATIVES",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R14": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LesseeOperatingLeasesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10601 - Disclosure - LEASES",
     "role": "http://www.fsbwa.com/role/DisclosureLeases",
     "shortName": "LEASES",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LesseeOperatingLeasesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R15": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RealEstateOwnedTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10701 - Disclosure - OTHER REAL ESTATE OWNED (OREO)",
     "role": "http://www.fsbwa.com/role/DisclosureOtherRealEstateOwnedOreo",
     "shortName": "OTHER REAL ESTATE OWNED (OREO)",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RealEstateOwnedTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R16": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DepositLiabilitiesDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10801 - Disclosure - DEPOSITS",
     "role": "http://www.fsbwa.com/role/DisclosureDeposits",
     "shortName": "DEPOSITS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DepositLiabilitiesDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R17": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10901 - Disclosure - COMMITMENTS AND CONTINGENCIES",
     "role": "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingencies",
     "shortName": "COMMITMENTS AND CONTINGENCIES",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R18": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11001 - Disclosure - FAIR VALUE MEASUREMENTS",
     "role": "http://www.fsbwa.com/role/DisclosureFairValueMeasurements",
     "shortName": "FAIR VALUE MEASUREMENTS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R19": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CompensationAndEmployeeBenefitPlansTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11101 - Disclosure - EMPLOYEE BENEFITS",
     "role": "http://www.fsbwa.com/role/DisclosureEmployeeBenefits",
     "shortName": "EMPLOYEE BENEFITS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CompensationAndEmployeeBenefitPlansTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R2": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:CashAndDueFromBanks",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00100 - Statement - CONSOLIDATED BALANCE SHEETS",
     "role": "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets",
     "shortName": "CONSOLIDATED BALANCE SHEETS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:CashAndDueFromBanks",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R20": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EarningsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11201 - Disclosure - EARNINGS PER SHARE",
     "role": "http://www.fsbwa.com/role/DisclosureEarningsPerShare",
     "shortName": "EARNINGS PER SHARE",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EarningsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R21": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11301 - Disclosure - STOCK-BASED COMPENSATION",
     "role": "http://www.fsbwa.com/role/DisclosureStockBasedCompensation",
     "shortName": "STOCK-BASED COMPENSATION",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R22": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11401 - Disclosure - REGULATORY CAPITAL",
     "role": "http://www.fsbwa.com/role/DisclosureRegulatoryCapital",
     "shortName": "REGULATORY CAPITAL",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R23": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SegmentReportingDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11501 - Disclosure - BUSINESS SEGMENTS",
     "role": "http://www.fsbwa.com/role/DisclosureBusinessSegments",
     "shortName": "BUSINESS SEGMENTS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SegmentReportingDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R24": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:GoodwillAndIntangibleAssetsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11601 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS",
     "role": "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssets",
     "shortName": "GOODWILL AND OTHER INTANGIBLE ASSETS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:GoodwillAndIntangibleAssetsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R25": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RevenueFromContractWithCustomerTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11701 - Disclosure - REVENUE FROM CONTRACTS WITH CUSTOMERS",
     "role": "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomers",
     "shortName": "REVENUE FROM CONTRACTS WITH CUSTOMERS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RevenueFromContractWithCustomerTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R26": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:BasisOfPresentationAndSignificantAccountingPoliciesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BasisOfAccountingPolicyPolicyTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "20102 - Disclosure - BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)",
     "role": "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies",
     "shortName": "BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)",
     "subGroupType": "policies",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:BasisOfPresentationAndSignificantAccountingPoliciesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BasisOfAccountingPolicyPolicyTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R27": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30103 - Disclosure - BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)",
     "role": "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesTables",
     "shortName": "BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R28": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30203 - Disclosure - INVESTMENTS (Tables)",
     "role": "http://www.fsbwa.com/role/DisclosureInvestmentsTables",
     "shortName": "INVESTMENTS (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R29": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:FinancingReceivablesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30303 - Disclosure - LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS (Tables)",
     "role": "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansTables",
     "shortName": "LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:FinancingReceivablesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R3": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DebtSecuritiesHeldToMaturityAllowanceForCreditLoss",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00105 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)",
     "role": "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheetsParenthetical",
     "shortName": "CONSOLIDATED BALANCE SHEETS (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "INF",
      "lang": null,
      "name": "us-gaap:PreferredStockParOrStatedValuePerShare",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Divide_USD_shares_7-IsufPSEU21lhkJg28_cw",
      "xsiNil": "false"
     }
    },
    "R30": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:TransfersAndServicingOfFinancialAssetsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfServicingAssetsAtAmortizedValueTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30403 - Disclosure - SERVICING RIGHTS (Tables)",
     "role": "http://www.fsbwa.com/role/DisclosureServicingRightsTables",
     "shortName": "SERVICING RIGHTS (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:TransfersAndServicingOfFinancialAssetsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfServicingAssetsAtAmortizedValueTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R31": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfFairValueHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30503 - Disclosure - DERIVATIVES (Tables)",
     "role": "http://www.fsbwa.com/role/DisclosureDerivativesTables",
     "shortName": "DERIVATIVES (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfFairValueHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R32": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:LesseeOperatingLeasesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LeaseCostTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30603 - Disclosure - LEASES (Tables)",
     "role": "http://www.fsbwa.com/role/DisclosureLeasesTables",
     "shortName": "LEASES (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:LesseeOperatingLeasesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LeaseCostTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R33": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:RealEstateOwnedTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OtherRealEstateRollForwardTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30703 - Disclosure - OTHER REAL ESTATE OWNED (OREO) (Tables)",
     "role": "http://www.fsbwa.com/role/DisclosureOtherRealEstateOwnedOreoTables",
     "shortName": "OTHER REAL ESTATE OWNED (OREO) (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:RealEstateOwnedTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OtherRealEstateRollForwardTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R34": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:DepositLiabilitiesDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "fsbw:ScheduleOfDepositLiabilitiesTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30803 - Disclosure - DEPOSITS (Tables)",
     "role": "http://www.fsbwa.com/role/DisclosureDepositsTables",
     "shortName": "DEPOSITS (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:DepositLiabilitiesDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "fsbw:ScheduleOfDepositLiabilitiesTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R35": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "fsbw:ScheduleOfOutstandingCommitmentsTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30903 - Disclosure - COMMITMENTS AND CONTINGENCIES (Tables)",
     "role": "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesTables",
     "shortName": "COMMITMENTS AND CONTINGENCIES (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "fsbw:ScheduleOfOutstandingCommitmentsTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R36": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31003 - Disclosure - FAIR VALUE MEASUREMENTS (Tables)",
     "role": "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsTables",
     "shortName": "FAIR VALUE MEASUREMENTS (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R37": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:EarningsPerShareTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31203 - Disclosure - EARNINGS PER SHARE (Tables)",
     "role": "http://www.fsbwa.com/role/DisclosureEarningsPerShareTables",
     "shortName": "EARNINGS PER SHARE (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:EarningsPerShareTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R38": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31303 - Disclosure - STOCK-BASED COMPENSATION (Tables)",
     "role": "http://www.fsbwa.com/role/DisclosureStockBasedCompensationTables",
     "shortName": "STOCK-BASED COMPENSATION (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R39": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfSegmentReportingInformationBySegmentTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31503 - Disclosure - BUSINESS SEGMENTS (Tables)",
     "role": "http://www.fsbwa.com/role/DisclosureBusinessSegmentsTables",
     "shortName": "BUSINESS SEGMENTS (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfSegmentReportingInformationBySegmentTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R4": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:InterestAndFeeIncomeOtherLoans",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00200 - Statement - CONSOLIDATED STATEMENTS OF INCOME",
     "role": "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome",
     "shortName": "CONSOLIDATED STATEMENTS OF INCOME",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:InterestAndFeeIncomeOtherLoans",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R40": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "fsbw:ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsByMajorClassTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31603 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)",
     "role": "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsTables",
     "shortName": "GOODWILL AND OTHER INTANGIBLE ASSETS (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "fsbw:ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsByMajorClassTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R41": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisaggregationOfRevenueTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31703 - Disclosure - REVENUE FROM CONTRACTS WITH CUSTOMERS (Tables)",
     "role": "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomersTables",
     "shortName": "REVENUE FROM CONTRACTS WITH CUSTOMERS (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisaggregationOfRevenueTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R42": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:SegmentReportingPolicyPolicyTextBlock",
       "us-gaap:BasisOfPresentationAndSignificantAccountingPoliciesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:NumberOfOperatingSegments",
      "reportCount": 1,
      "unitRef": "Unit_Standard_segment_dVBAgXG_6k-blx50oUrIqQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40101 - Disclosure - BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesDetails",
     "shortName": "BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:BasisOfPresentationAndSignificantAccountingPoliciesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022_srt_StatementGeographicalAxis_fsbw_PugetSoundMember_VDH668C39kGYeQBN5-AJwA",
      "decimals": "INF",
      "lang": null,
      "name": "fsbw:NumberOfBankBranches",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_item_Sji2WNaN6EKZJwTG5Ahp1A",
      "xsiNil": "false"
     }
    },
    "R43": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "2",
      "first": true,
      "lang": null,
      "name": "us-gaap:EarningsPerShareBasic",
      "reportCount": 1,
      "unitRef": "Unit_Divide_USD_shares_7-IsufPSEU21lhkJg28_cw",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40102 - Disclosure - BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Error Corrections (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesErrorCorrectionsDetails",
     "shortName": "BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Error Corrections (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_12_31_2021_srt_RestatementAxis_srt_RevisionOfPriorPeriodErrorCorrectionAdjustmentMember_6OpIjszbFk-yLpekIqXMQg",
      "decimals": "-5",
      "lang": null,
      "name": "us-gaap:NoninterestBearingDepositLiabilities",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R44": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40103 - Disclosure - BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Adoption (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
     "shortName": "BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Adoption (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-5",
      "lang": null,
      "name": "us-gaap:FinancingReceivableAccruedInterestAfterAllowanceForCreditLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R45": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock",
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40201 - Disclosure - INVESTMENTS - Available-for-sale securities reconciliation (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails",
     "shortName": "INVESTMENTS - Available-for-sale securities reconciliation (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock",
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R46": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "fsbw:HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsNumber",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_security_Vww7gJSbBEiKMbrhM5yzIQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40202 - Disclosure - INVESTMENTS - Narrative (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails",
     "shortName": "INVESTMENTS - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "fsbw:HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsNumber",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_security_Vww7gJSbBEiKMbrhM5yzIQ",
      "xsiNil": "false"
     }
    },
    "R47": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DebtSecuritiesHeldToMaturityAllowanceForCreditLoss",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40203 - Disclosure - INVESTMENTS - Allowance for credit losses (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureInvestmentsAllowanceForCreditLossesDetails",
     "shortName": "INVESTMENTS - Allowance for credit losses (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:DebtSecuritiesHeldToMaturityAllowanceForCreditLossTableTextBlock",
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_us-gaap_FinancialInstrumentAxis_us-gaap_CorporateDebtSecuritiesMember_E8pZVMifSE2RxEFtvF43cA",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:DebtSecuritiesHeldToMaturityCreditLossExpenseReversal",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R48": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DebtSecuritiesHeldToMaturityAllowanceForCreditLoss",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40204 - Disclosure - INVESTMENTS - Amortized cost of debt (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureInvestmentsAmortizedCostOfDebtDetails",
     "shortName": "INVESTMENTS - Amortized cost of debt (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:DebtSecuritiesHeldToMaturityCreditQualityIndicatorTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022_srt_CreditRatingStandardPoorsAxis_srt_StandardPoorsBBBRatingMember_us-gaap_FinancialInstrumentAxis_us-gaap_CorporateDebtSecuritiesMember_-tyU5du4Xk6HA_evUM_D6Q",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:DebtSecuritiesHeldToMaturityAllowanceForCreditLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R49": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40205 - Disclosure - INVESTMENTS - Investments with Unrealized Losses Policy (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails",
     "shortName": "INVESTMENTS - Investments with Unrealized Losses Policy (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R5": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00300 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME",
     "role": "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome",
     "shortName": "CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R50": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesDebt",
       "us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesDebt",
       "us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesDebt",
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesDebt",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40206 - Disclosure - INVESTMENTS - Available for Sale Securities by Contractual Maturity (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails",
     "shortName": "INVESTMENTS - Available for Sale Securities by Contractual Maturity (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesDebt",
       "us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesDebt",
       "us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesDebt",
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesDebt",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R51": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
       "us-gaap:FinancingReceivablesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:LoansAndLeasesReceivableGrossCarryingAmount",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40301 - Disclosure - LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Composition of Loan Portfolio (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
     "shortName": "LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Composition of Loan Portfolio (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R52": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "fsbw:LoanPortfolioSegmentPolicyTextBlock",
       "us-gaap:FinancingReceivablesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "fsbw:NumberOfLoanPortfolioSegments",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_segment_dVBAgXG_6k-blx50oUrIqQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40302 - Disclosure - LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Narrative (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansNarrativeDetails",
     "shortName": "LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "fsbw:LoanPortfolioSegmentPolicyTextBlock",
       "us-gaap:FinancingReceivablesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "fsbw:NumberOfLoanPortfolioSegments",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_segment_dVBAgXG_6k-blx50oUrIqQ",
      "xsiNil": "false"
     }
    },
    "R53": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ProvisionForLoanLeaseAndOtherLosses",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40303 - Disclosure - LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Allowance for Loan Losses by Loan Categories (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails",
     "shortName": "LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Allowance for Loan Losses by Loan Categories (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ProvisionForLoanLeaseAndOtherLosses",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R54": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
       "us-gaap:FinancingReceivablesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:LoansAndLeasesReceivableGrossCarryingAmount",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40304 - Disclosure - LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Aging Analysis of Past Due Loans (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
     "shortName": "LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Aging Analysis of Past Due Loans (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "0",
      "lang": null,
      "name": "fsbw:NumberOfTroubledDebtRestructuredLoans",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R55": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ImpairedFinancingReceivablesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_12_31_2021_XLce-CxVaUikTZtnJOOsVg",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40305 - Disclosure - LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Financing Receivables, Related Allowance Recorded and No Related Allowance Recorded (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
     "shortName": "LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Financing Receivables, Related Allowance Recorded and No Related Allowance Recorded (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ImpairedFinancingReceivablesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_12_31_2021_XLce-CxVaUikTZtnJOOsVg",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R56": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2021_To_6_30_2021_pnQHTNZaVk-yqukxzBayGQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40306 - Disclosure - LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Average Recorded Investment (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
     "shortName": "LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Average Recorded Investment (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2021_To_6_30_2021_pnQHTNZaVk-yqukxzBayGQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R57": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:FinancingReceivableOriginatedInCurrentFiscalYear",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40307 - Disclosure - LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Risk Rated Loan Balances (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails",
     "shortName": "LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Risk Rated Loan Balances (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:FinancingReceivableOriginatedInCurrentFiscalYear",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R58": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfFinancingReceivablesNonAccrualStatusTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:FinancingReceivableNonaccrualNoAllowance",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40308 - Disclosure - LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Amortized Cost Basis of Loans (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
     "shortName": "LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Amortized Cost Basis of Loans (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:FinancingReceivableNonaccrualInterestIncome",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R59": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "fsbw:ScheduleOfCollateralDependentImpairedLoansTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "fsbw:ImpairedLoansCollateral",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40309 - Disclosure - LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Amortized Cost Basis of Collateral Dependent Impaired Loans (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
     "shortName": "LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS - Amortized Cost Basis of Collateral Dependent Impaired Loans (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "fsbw:ScheduleOfCollateralDependentImpairedLoansTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "fsbw:ImpairedLoansCollateral",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R6": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_12_31_2020_us-gaap_StatementEquityComponentsAxis_us-gaap_CommonStockMember_0vT5JCbCl0mrfr7CuqjujQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:StockholdersEquity",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00400 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY",
     "role": "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity",
     "shortName": "CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_12_31_2020_us-gaap_StatementEquityComponentsAxis_us-gaap_CommonStockMember_0vT5JCbCl0mrfr7CuqjujQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:StockholdersEquity",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R60": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40401 - Disclosure - SERVICING RIGHTS - Narrative (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureServicingRightsNarrativeDetails",
     "shortName": "SERVICING RIGHTS - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R61": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfServicingAssetsAtAmortizedValueTextBlock",
       "us-gaap:TransfersAndServicingOfFinancialAssetsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_3_31_2022_ENFK5abzuEOHFFkMh_H-pQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ServicingAssetAtAmortizedValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40402 - Disclosure - SERVICING RIGHTS - Servicing Rights (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureServicingRightsServicingRightsDetails",
     "shortName": "SERVICING RIGHTS - Servicing Rights (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfServicingAssetsAtAmortizedValueTextBlock",
       "us-gaap:TransfersAndServicingOfFinancialAssetsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_3_31_2022_ENFK5abzuEOHFFkMh_H-pQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ServicingAssetAtAmortizedValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R62": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfSensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrServicingLiabilitiesTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_us-gaap_FinancialInstrumentAxis_fsbw_MortgageServicingRightsMember_XKLdh1BzhkebP39qXv9aEA",
      "decimals": "3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueDiscountRate",
      "reportCount": 1,
      "unitRef": "Unit_Standard_pure_ZKDt15-DmUCw9k_EdAqk_Q",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40403 - Disclosure - SERVICING RIGHTS - Valuation Assumptions (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureServicingRightsValuationAssumptionsDetails",
     "shortName": "SERVICING RIGHTS - Valuation Assumptions (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_us-gaap_FinancialInstrumentAxis_fsbw_MortgageServicingRightsMember_XKLdh1BzhkebP39qXv9aEA",
      "decimals": null,
      "lang": "en-US",
      "name": "us-gaap:ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueWeightedAverageLife1",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R63": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "4",
      "first": true,
      "lang": null,
      "name": "fsbw:ServicingLiabilityAtFairValueBasisPointsDropInNoteRateAssumptionOne",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_ZKDt15-DmUCw9k_EdAqk_Q",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40404 - Disclosure - SERVICING RIGHTS - Changes in Valuation Assumptions (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails",
     "shortName": "SERVICING RIGHTS - Changes in Valuation Assumptions (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "4",
      "first": true,
      "lang": null,
      "name": "fsbw:ServicingLiabilityAtFairValueBasisPointsDropInNoteRateAssumptionOne",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_ZKDt15-DmUCw9k_EdAqk_Q",
      "xsiNil": "false"
     }
    },
    "R64": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "p",
       "us-gaap:DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40501 - Disclosure - DERIVATIVES (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureDerivativesDetails",
     "shortName": "DERIVATIVES (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "p",
       "us-gaap:DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R65": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_12_31_2021_XLce-CxVaUikTZtnJOOsVg",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:FairValueHedgesAtFairValueNet",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40502 - Disclosure - DERIVATIVES - Cumulative-basis Adjustment for Fair Value Hedges (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureDerivativesCumulativeBasisAdjustmentForFairValueHedgesDetails",
     "shortName": "DERIVATIVES - Cumulative-basis Adjustment for Fair Value Hedges (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_12_31_2021_XLce-CxVaUikTZtnJOOsVg",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:FairValueHedgesAtFairValueNet",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R66": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022_us-gaap_DerivativeInstrumentRiskAxis_us-gaap_InterestRateSwapMember_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_us-gaap_CashFlowHedgingMember_us-gaap_HedgingDesignationAxis_us-gaap_DesignatedAsHedgingInstrumentMember_r2UohlDJP0W8fw75r9KN_A",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DerivativeNotionalAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40503 - Disclosure - DERIVATIVES - Derivative instruments (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails",
     "shortName": "DERIVATIVES - Derivative instruments (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022_us-gaap_DerivativeInstrumentRiskAxis_us-gaap_InterestRateSwapMember_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_us-gaap_CashFlowHedgingMember_us-gaap_HedgingDesignationAxis_us-gaap_DesignatedAsHedgingInstrumentMember_r2UohlDJP0W8fw75r9KN_A",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DerivativeNotionalAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R67": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40504 - Disclosure - DERIVATIVES - Effect of Fair Value and Cash Flow Hedge Accounting (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails",
     "shortName": "DERIVATIVES - Effect of Fair Value and Cash Flow Hedge Accounting (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-5",
      "lang": null,
      "name": "fsbw:GainLossOnChangeInFairValueOfNonhedgingDerivatives",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R68": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:OffsettingAssetsTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022_us-gaap_DerivativeInstrumentRiskAxis_us-gaap_InterestRateSwapMember_2iioEp5qakifCJSt2vcQyw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DerivativeFairValueOfDerivativeAsset",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40505 - Disclosure - DERIVATIVES - Offsetting Derivative Assets (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeAssetsDetails",
     "shortName": "DERIVATIVES - Offsetting Derivative Assets (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:OffsettingAssetsTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022_us-gaap_DerivativeInstrumentRiskAxis_us-gaap_InterestRateSwapMember_2iioEp5qakifCJSt2vcQyw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DerivativeFairValueOfDerivativeAsset",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R69": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:OffsettingLiabilitiesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_12_31_2021_us-gaap_DerivativeInstrumentRiskAxis_us-gaap_InterestRateSwapMember_VpOdYwmKLkqWolDPA_9mVA",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DerivativeFairValueOfDerivativeLiability",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40506 - Disclosure - DERIVATIVES - Offsetting Derivative Liabilities (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeLiabilitiesDetails",
     "shortName": "DERIVATIVES - Offsetting Derivative Liabilities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:OffsettingLiabilitiesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_12_31_2021_us-gaap_DerivativeInstrumentRiskAxis_us-gaap_InterestRateSwapMember_VpOdYwmKLkqWolDPA_9mVA",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DerivativeFairValueOfDerivativeLiability",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R7": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "2",
      "first": true,
      "lang": null,
      "name": "us-gaap:CommonStockDividendsPerShareCashPaid",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Divide_USD_shares_7-IsufPSEU21lhkJg28_cw",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00405 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical)",
     "role": "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquityParenthetical",
     "shortName": "CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "2",
      "first": true,
      "lang": null,
      "name": "us-gaap:CommonStockDividendsPerShareCashPaid",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Divide_USD_shares_7-IsufPSEU21lhkJg28_cw",
      "xsiNil": "false"
     }
    },
    "R70": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DerivativeNetLiabilityPositionAggregateFairValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40507 - Disclosure - DERIVATIVES - Credit-risk-related Contingent Features (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureDerivativesCreditRiskRelatedContingentFeaturesDetails",
     "shortName": "DERIVATIVES - Credit-risk-related Contingent Features (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:DerivativeNetLiabilityPositionAggregateFairValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R71": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:LesseeOperatingLeasesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LesseeOperatingLeaseExistenceOfOptionToExtend",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40601 - Disclosure - LEASES (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureLeasesDetails",
     "shortName": "LEASES (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:LesseeOperatingLeasesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LesseeOperatingLeaseExistenceOfOptionToExtend",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R72": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:LeaseCostTableTextBlock",
       "us-gaap:LesseeOperatingLeasesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:OperatingLeaseCost",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40602 - Disclosure - LEASES - Components of lease cost and Supplemental information related to operating leases (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureLeasesComponentsOfLeaseCostAndSupplementalInformationRelatedToOperatingLeasesDetails",
     "shortName": "LEASES - Components of lease cost and Supplemental information related to operating leases (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:LeaseCostTableTextBlock",
       "us-gaap:LesseeOperatingLeasesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:OperatingLeaseCost",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R73": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:LesseeOperatingLeaseLiabilityMaturityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40603 - Disclosure - LEASES - Maturities of operating lease liabilities (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails",
     "shortName": "LEASES - Maturities of operating lease liabilities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:LesseeOperatingLeaseLiabilityMaturityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R74": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:OtherRealEstateRollForwardTableTextBlock",
       "us-gaap:RealEstateOwnedTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_3_31_2022_ENFK5abzuEOHFFkMh_H-pQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:OtherRealEstateAndForeclosedAssets",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40701 - Disclosure - OTHER REAL ESTATE OWNED (OREO) - Activity related to OREO (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureOtherRealEstateOwnedOreoActivityRelatedToOreoDetails",
     "shortName": "OTHER REAL ESTATE OWNED (OREO) - Activity related to OREO (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:OtherRealEstateRollForwardTableTextBlock",
       "us-gaap:RealEstateOwnedTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_3_31_2022_ENFK5abzuEOHFFkMh_H-pQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:OtherRealEstateAndForeclosedAssets",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R75": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:RealEstateOwnedTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:NumberOfRealEstateProperties",
      "reportCount": 1,
      "unitRef": "Unit_Standard_property_0pJB3aOSF029ZRL7lg4qQQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40702 - Disclosure - OTHER REAL ESTATE OWNED (OREO) - Narrative (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureOtherRealEstateOwnedOreoNarrativeDetails",
     "shortName": "OTHER REAL ESTATE OWNED (OREO) - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "fsbw:RealEstateOwnedHoldingCosts",
       "fsbw:RealEstateOwnedHoldingCosts",
       "fsbw:RealEstateOwnedHoldingCosts",
       "p",
       "us-gaap:RealEstateOwnedTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "lang": null,
      "name": "fsbw:RealEstateOwnedHoldingCosts",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R76": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "fsbw:ScheduleOfDepositLiabilitiesTableTextBlock",
       "us-gaap:DepositLiabilitiesDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:NoninterestBearingDomesticDepositChecking",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40801 - Disclosure - DEPOSITS - Deposit Liabilities (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails",
     "shortName": "DEPOSITS - Deposit Liabilities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "fsbw:ScheduleOfDepositLiabilitiesTableTextBlock",
       "us-gaap:DepositLiabilitiesDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:NoninterestBearingDomesticDepositChecking",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R77": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "fsbw:ScheduleOfMaturitiesOfTimeDepositsTableTextBlock",
       "us-gaap:DepositLiabilitiesDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:TimeDepositMaturitiesRemainderOfFiscalYear",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40802 - Disclosure - DEPOSITS - Maturities of Time Deposits for Future Periods (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureDepositsMaturitiesOfTimeDepositsForFuturePeriodsDetails",
     "shortName": "DEPOSITS - Maturities of Time Deposits for Future Periods (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "fsbw:ScheduleOfMaturitiesOfTimeDepositsTableTextBlock",
       "us-gaap:DepositLiabilitiesDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:TimeDepositMaturitiesRemainderOfFiscalYear",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R78": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "fsbw:ScheduleOfInterestExpenseByDepositCategoryTableTextBlock",
       "us-gaap:DepositLiabilitiesDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:InterestExpenseDomesticDepositLiabilitiesChecking",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40803 - Disclosure - DEPOSITS - Interest Expense by Deposit Category (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureDepositsInterestExpenseByDepositCategoryDetails",
     "shortName": "DEPOSITS - Interest Expense by Deposit Category (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "fsbw:ScheduleOfInterestExpenseByDepositCategoryTableTextBlock",
       "us-gaap:DepositLiabilitiesDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:InterestExpenseDomesticDepositLiabilitiesChecking",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R79": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "fsbw:ScheduleOfOutstandingCommitmentsTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022_us-gaap_FinancialInstrumentAxis_us-gaap_CommitmentsToExtendCreditMember_tExtQNG66Umw8GI6Q_jq2Q",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:FairValueDisclosureOffbalanceSheetRisksFaceAmountAsset",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40901 - Disclosure - COMMITMENTS AND CONTINGENCIES - Commitment (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
     "shortName": "COMMITMENTS AND CONTINGENCIES - Commitment (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "fsbw:ScheduleOfOutstandingCommitmentsTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022_us-gaap_FinancialInstrumentAxis_us-gaap_CommitmentsToExtendCreditMember_tExtQNG66Umw8GI6Q_jq2Q",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:FairValueDisclosureOffbalanceSheetRisksFaceAmountAsset",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R8": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ProfitLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00500 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS",
     "role": "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows",
     "shortName": "CONSOLIDATED STATEMENTS OF CASH FLOWS",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ProfitLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R80": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "fsbw:AllowanceForCreditLossesOnUnfundedLoanCommitments",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40902 - Disclosure - COMMITMENTS AND CONTINGENCIES - Narrative (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails",
     "shortName": "COMMITMENTS AND CONTINGENCIES - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": "-5",
      "lang": null,
      "name": "fsbw:SaleOfLoansToFederalHomeLoanBank",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R81": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:LoansReceivableFairValueDisclosure",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41001 - Disclosure - FAIR VALUE MEASUREMENTS - Available for Sale Securities Measured at Fair Value on a Recurring Basis (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
     "shortName": "FAIR VALUE MEASUREMENTS - Available for Sale Securities Measured at Fair Value on a Recurring Basis (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "p",
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022_us-gaap_FairValueByFairValueHierarchyLevelAxis_us-gaap_FairValueInputsLevel2Member_us-gaap_FinancialInstrumentAxis_us-gaap_ResidentialMortgageMember_GZJxjoFYbkqeDSjE0yYkMw",
      "decimals": "-5",
      "lang": null,
      "name": "us-gaap:LoansReceivableFairValueDisclosure",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R82": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "fsbw:OtherRealEstateOwned",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41002 - Disclosure - FAIR VALUE MEASUREMENTS - Loans Individually Evaluated, OREO and Servicing Rights on Non-recurring Basis (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsLoansIndividuallyEvaluatedOreoAndServicingRightsOnNonRecurringBasisDetails",
     "shortName": "FAIR VALUE MEASUREMENTS - Loans Individually Evaluated, OREO and Servicing Rights on Non-recurring Basis (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfValuationAllowanceForImpairmentOfRecognizedServicingAssetsTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022_us-gaap_FairValueByMeasurementFrequencyAxis_us-gaap_FairValueMeasurementsNonrecurringMember_QaSu8ggHBkOSSZwV-XoJsA",
      "decimals": "-3",
      "lang": null,
      "name": "fsbw:LoansIndividuallyEvaluatedFairValueDisclosure",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R83": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022_srt_RangeAxis_srt_MinimumMember_us-gaap_DerivativeInstrumentRiskAxis_us-gaap_InterestRateLockCommitmentsMember_us-gaap_FairValueByFairValueHierarchyLevelAxis_us-gaap_FairValueInputsLevel3Member_us-gaap_FairValueByMeasurementFrequencyAxis_us-gaap_FairValueMeasurementsRecurringMember_GBzs5bnt_EyqE8oAPR-KRA",
      "decimals": "2",
      "first": true,
      "lang": null,
      "name": "us-gaap:DebtSecuritiesAvailableForSaleMeasurementInput",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_ZKDt15-DmUCw9k_EdAqk_Q",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41003 - Disclosure - FAIR VALUE MEASUREMENTS - Discount Rate (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
     "shortName": "FAIR VALUE MEASUREMENTS - Discount Rate (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022_srt_RangeAxis_srt_MinimumMember_us-gaap_DerivativeInstrumentRiskAxis_us-gaap_InterestRateLockCommitmentsMember_us-gaap_FairValueByFairValueHierarchyLevelAxis_us-gaap_FairValueInputsLevel3Member_us-gaap_FairValueByMeasurementFrequencyAxis_us-gaap_FairValueMeasurementsRecurringMember_GBzs5bnt_EyqE8oAPR-KRA",
      "decimals": "2",
      "first": true,
      "lang": null,
      "name": "us-gaap:DebtSecuritiesAvailableForSaleMeasurementInput",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_ZKDt15-DmUCw9k_EdAqk_Q",
      "xsiNil": "false"
     }
    },
    "R84": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_3_31_2022_us-gaap_DerivativeInstrumentRiskAxis_us-gaap_InterestRateLockCommitmentsMember_Wwa6zWadqESznLBS4_6DBw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41004 - Disclosure - FAIR VALUE MEASUREMENTS - Fair Value Level 3 on recurring basis (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueLevel3OnRecurringBasisDetails",
     "shortName": "FAIR VALUE MEASUREMENTS - Fair Value Level 3 on recurring basis (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_3_31_2022_us-gaap_DerivativeInstrumentRiskAxis_us-gaap_InterestRateLockCommitmentsMember_Wwa6zWadqESznLBS4_6DBw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R85": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:CertificatesOfDepositAtCarryingValue",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41005 - Disclosure - FAIR VALUE MEASUREMENTS - Fair Value By Balance Sheet Grouping (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails",
     "shortName": "FAIR VALUE MEASUREMENTS - Fair Value By Balance Sheet Grouping (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:FairValueByBalanceSheetGroupingTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022_us-gaap_FairValueByFairValueHierarchyLevelAxis_us-gaap_FairValueInputsLevel1Member_us-gaap_FairValueByMeasurementBasisAxis_us-gaap_CarryingReportedAmountFairValueDisclosureMember_chnjUrQogUWFsFe2_WwtkA",
      "decimals": "-3",
      "lang": null,
      "name": "fsbw:CashDueFromBanksAndInterestBearingDepositsAtOtherFinancialInstitutionsFairValueDisclosure",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R86": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:CompensationAndEmployeeBenefitPlansTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2012_To_1_1_2012_B538eNDU0kmCRlvjQf_O_g",
      "decimals": "2",
      "first": true,
      "lang": null,
      "name": "fsbw:EmployeeStockOwnershipPlanVestedPercentAfterRequisiteServicePeriodIsMet",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_ZKDt15-DmUCw9k_EdAqk_Q",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41101 - Disclosure - EMPLOYEE BENEFITS - Narrative (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureEmployeeBenefitsNarrativeDetails",
     "shortName": "EMPLOYEE BENEFITS - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:CompensationAndEmployeeBenefitPlansTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2012_To_1_1_2012_B538eNDU0kmCRlvjQf_O_g",
      "decimals": "2",
      "first": true,
      "lang": null,
      "name": "fsbw:EmployeeStockOwnershipPlanVestedPercentAfterRequisiteServicePeriodIsMet",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_ZKDt15-DmUCw9k_EdAqk_Q",
      "xsiNil": "false"
     }
    },
    "R87": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41201 - Disclosure - EARNINGS PER SHARE - Schedule of Earnings Per Share, Basic and Diluted (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureEarningsPerShareScheduleOfEarningsPerShareBasicAndDilutedDetails",
     "shortName": "EARNINGS PER SHARE - Schedule of Earnings Per Share, Basic and Diluted (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
       "us-gaap:EarningsPerShareTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "lang": null,
      "name": "fsbw:DividendsAndUndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R88": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod",
      "reportCount": 1,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41301 - Disclosure - STOCK-BASED COMPENSATION - Narrative (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails",
     "shortName": "STOCK-BASED COMPENSATION - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_us-gaap_PlanNameAxis_fsbw_EquityIncentivePlan2018Member_OP6zuFVCPU2meS_By8uVtA",
      "decimals": "0",
      "lang": null,
      "name": "us-gaap:AllocatedShareBasedCompensationExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R89": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod",
      "reportCount": 1,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41302 - Disclosure - STOCK-BASED COMPENSATION - Stock Option Activity (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails",
     "shortName": "STOCK-BASED COMPENSATION - Stock Option Activity (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_us-gaap_AwardTypeAxis_us-gaap_StockOptionMember_MAq5Bm395kW3QNq2_lYgPA",
      "decimals": "3",
      "lang": null,
      "name": "fsbw:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpectedForfeitureRateOverContractualTerm",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_ZKDt15-DmUCw9k_EdAqk_Q",
      "xsiNil": "false"
     }
    },
    "R9": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BasisOfPresentationAndSignificantAccountingPoliciesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10101 - Disclosure - BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES",
     "role": "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPolicies",
     "shortName": "BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BasisOfPresentationAndSignificantAccountingPoliciesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R90": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfNonvestedShareActivityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_12_31_2021_us-gaap_AwardTypeAxis_us-gaap_RestrictedStockMember_5YPJTu9mGU2t3h5_7Y0ErA",
      "decimals": "0",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_BkUzG4izNECx6iTSkz85Sg",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41303 - Disclosure - STOCK-BASED COMPENSATION - Restricted Stock Awards (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails",
     "shortName": "STOCK-BASED COMPENSATION - Restricted Stock Awards (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfNonvestedShareActivityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_12_31_2021_us-gaap_AwardTypeAxis_us-gaap_RestrictedStockMember_5YPJTu9mGU2t3h5_7Y0ErA",
      "decimals": "0",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_BkUzG4izNECx6iTSkz85Sg",
      "xsiNil": "false"
     }
    },
    "R91": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "1",
      "first": true,
      "lang": null,
      "name": "us-gaap:TierOneRiskBasedCapitalToRiskWeightedAssets",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_ZKDt15-DmUCw9k_EdAqk_Q",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41401 - Disclosure - REGULATORY CAPITAL - Regulatory Capital Ratios Policy (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureRegulatoryCapitalRegulatoryCapitalRatiosPolicyDetails",
     "shortName": "REGULATORY CAPITAL - Regulatory Capital Ratios Policy (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "1",
      "first": true,
      "lang": null,
      "name": "us-gaap:TierOneRiskBasedCapitalToRiskWeightedAssets",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_ZKDt15-DmUCw9k_EdAqk_Q",
      "xsiNil": "false"
     }
    },
    "R92": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:SegmentReportingPolicyPolicyTextBlock",
       "us-gaap:BasisOfPresentationAndSignificantAccountingPoliciesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2022_To_6_30_2022_jCpKIhs_9kG0ysJukXzS_w",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:NumberOfOperatingSegments",
      "reportCount": 1,
      "unitRef": "Unit_Standard_segment_dVBAgXG_6k-blx50oUrIqQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41501 - Disclosure - BUSINESS SEGMENTS - Narrative (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureBusinessSegmentsNarrativeDetails",
     "shortName": "BUSINESS SEGMENTS - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:SegmentReportingDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022_srt_ProductOrServiceAxis_fsbw_RetailDepositMember_srt_StatementGeographicalAxis_fsbw_PacificNorthwestMember_a3sPsN212Ua24PRJUta-wA",
      "decimals": "INF",
      "lang": null,
      "name": "fsbw:NumberOfBankBranches",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_item_Sji2WNaN6EKZJwTG5Ahp1A",
      "xsiNil": "false"
     }
    },
    "R93": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:InterestIncomeExpenseNet",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41502 - Disclosure - BUSINESS SEGMENTS - Segment Financial Results (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails",
     "shortName": "BUSINESS SEGMENTS - Segment Financial Results (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfSegmentReportingInformationBySegmentTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:AssetsAverageOutstanding",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R94": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "As_Of_6_30_2022__G7-O_QvgkCPFHvELyk6hQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:Goodwill",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41601 - Disclosure - GOODWILL AND OTHER INTANGIBLE ASSETS (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails",
     "shortName": "GOODWILL AND OTHER INTANGIBLE ASSETS (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:GoodwillAndIntangibleAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_1_1_2021_To_12_31_2021__ubsQmCU3EanlNxbDsThFA",
      "decimals": "-5",
      "lang": null,
      "name": "us-gaap:GoodwillImpairmentLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    },
    "R95": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:DisaggregationOfRevenueTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41701 - Disclosure - REVENUE FROM CONTRACTS WITH CUSTOMERS (Details)",
     "role": "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomersDetails",
     "shortName": "REVENUE FROM CONTRACTS WITH CUSTOMERS (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:DisaggregationOfRevenueTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "fsbw-20220630x10q.htm",
      "contextRef": "Duration_4_1_2022_To_6_30_2022_ryVkxZzKPEiqMofOYAb5og",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_YyFFA9BLwkGuQnYmFmgy6w",
      "xsiNil": "false"
     }
    }
   },
   "segmentCount": 110,
   "tag": {
    "dei_AmendmentFlag": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.",
        "label": "Amendment Flag",
        "terseLabel": "Amendment Flag"
       }
      }
     },
     "localname": "AmendmentFlag",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_CityAreaCode": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Area code of city",
        "label": "City Area Code"
       }
      }
     },
     "localname": "CityAreaCode",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_CoverAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cover page.",
        "label": "Document And Entity Information"
       }
      }
     },
     "localname": "CoverAbstract",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "xbrltype": "stringItemType"
    },
    "dei_CurrentFiscalYearEndDate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "End date of current fiscal year in the format --MM-DD.",
        "label": "Current Fiscal Year End Date",
        "terseLabel": "Current Fiscal Year End Date"
       }
      }
     },
     "localname": "CurrentFiscalYearEndDate",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "gMonthDayItemType"
    },
    "dei_DocumentFiscalPeriodFocus": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fiscal period values are FY, Q1, Q2, and Q3.  1st, 2nd and 3rd quarter 10-Q or 10-QT statements have value Q1, Q2, and Q3 respectively, with 10-K, 10-KT or other fiscal year statements having FY.",
        "label": "Document Fiscal Period Focus",
        "terseLabel": "Document Fiscal Period Focus"
       }
      }
     },
     "localname": "DocumentFiscalPeriodFocus",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "fiscalPeriodItemType"
    },
    "dei_DocumentFiscalYearFocus": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This is focus fiscal year of the document report in YYYY format. For a 2006 annual report, which may also provide financial information from prior periods, fiscal 2006 should be given as the fiscal year focus. Example: 2006.",
        "label": "Document Fiscal Year Focus",
        "terseLabel": "Document Fiscal Year Focus"
       }
      }
     },
     "localname": "DocumentFiscalYearFocus",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "gYearItemType"
    },
    "dei_DocumentPeriodEndDate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period.  The format of the date is YYYY-MM-DD.",
        "label": "Document Period End Date",
        "terseLabel": "Document Period End Date"
       }
      }
     },
     "localname": "DocumentPeriodEndDate",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "dateItemType"
    },
    "dei_DocumentQuarterlyReport": {
     "auth_ref": [
      "r762"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true only for a form used as an quarterly report.",
        "label": "Document Quarterly Report"
       }
      }
     },
     "localname": "DocumentQuarterlyReport",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_DocumentTransitionReport": {
     "auth_ref": [
      "r763"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true only for a form used as a transition report.",
        "label": "Document Transition Report"
       }
      }
     },
     "localname": "DocumentTransitionReport",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_DocumentType": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.",
        "label": "Document Type",
        "terseLabel": "Document Type"
       }
      }
     },
     "localname": "DocumentType",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "submissionTypeItemType"
    },
    "dei_EntityAddressAddressLine1": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Address Line 1 such as Attn, Building Name, Street Name",
        "label": "Entity Address, Address Line One"
       }
      }
     },
     "localname": "EntityAddressAddressLine1",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressCityOrTown": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of the City or Town",
        "label": "Entity Address, City or Town"
       }
      }
     },
     "localname": "EntityAddressCityOrTown",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressPostalZipCode": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Code for the postal or zip code",
        "label": "Entity Address, Postal Zip Code"
       }
      }
     },
     "localname": "EntityAddressPostalZipCode",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressStateOrProvince": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of the state or province.",
        "label": "Entity Address, State or Province"
       }
      }
     },
     "localname": "EntityAddressStateOrProvince",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "stateOrProvinceItemType"
    },
    "dei_EntityCentralIndexKey": {
     "auth_ref": [
      "r760"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.",
        "label": "Entity Central Index Key",
        "terseLabel": "Entity Central Index Key"
       }
      }
     },
     "localname": "EntityCentralIndexKey",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "centralIndexKeyItemType"
    },
    "dei_EntityCommonStockSharesOutstanding": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicate number of shares or other units outstanding of each of registrant's classes of capital or common stock or other ownership interests, if and as stated on cover of related periodic report. Where multiple classes or units exist define each class/interest by adding class of stock items such as Common Class A [Member], Common Class B [Member] or Partnership Interest [Member] onto the Instrument [Domain] of the Entity Listings, Instrument.",
        "label": "Entity Common Stock, Shares Outstanding",
        "terseLabel": "Entity Common Stock, Shares Outstanding"
       }
      }
     },
     "localname": "EntityCommonStockSharesOutstanding",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "sharesItemType"
    },
    "dei_EntityCurrentReportingStatus": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicate 'Yes' or 'No' whether registrants (1) have filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that registrants were required to file such reports), and (2) have been subject to such filing requirements for the past 90 days. This information should be based on the registrant's current or most recent filing containing the related disclosure.",
        "label": "Entity Current Reporting Status"
       }
      }
     },
     "localname": "EntityCurrentReportingStatus",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityEmergingGrowthCompany": {
     "auth_ref": [
      "r760"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicate if registrant meets the emerging growth company criteria.",
        "label": "Entity Emerging Growth Company"
       }
      }
     },
     "localname": "EntityEmergingGrowthCompany",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntityFileNumber": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.",
        "label": "Entity File Number"
       }
      }
     },
     "localname": "EntityFileNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "fileNumberItemType"
    },
    "dei_EntityFilerCategory": {
     "auth_ref": [
      "r760"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicate whether the registrant is one of the following: Large Accelerated Filer, Accelerated Filer, Non-accelerated Filer. Definitions of these categories are stated in Rule 12b-2 of the Exchange Act. This information should be based on the registrant's current or most recent filing containing the related disclosure.",
        "label": "Entity Filer Category",
        "terseLabel": "Entity Filer Category"
       }
      }
     },
     "localname": "EntityFilerCategory",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "filerCategoryItemType"
    },
    "dei_EntityIncorporationStateCountryCode": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Two-character EDGAR code representing the state or country of incorporation.",
        "label": "Entity Incorporation, State or Country Code"
       }
      }
     },
     "localname": "EntityIncorporationStateCountryCode",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "edgarStateCountryItemType"
    },
    "dei_EntityInteractiveDataCurrent": {
     "auth_ref": [
      "r782"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true when the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).",
        "label": "Entity Interactive Data Current"
       }
      }
     },
     "localname": "EntityInteractiveDataCurrent",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityNumberOfEmployees": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of persons employed by the Entity",
        "label": "Entity Number of Employees",
        "terseLabel": "FTEs"
       }
      }
     },
     "localname": "EntityNumberOfEmployees",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails"
     ],
     "xbrltype": "decimalItemType"
    },
    "dei_EntityRegistrantName": {
     "auth_ref": [
      "r760"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.",
        "label": "Entity Registrant Name",
        "terseLabel": "Entity Registrant Name"
       }
      }
     },
     "localname": "EntityRegistrantName",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityShellCompany": {
     "auth_ref": [
      "r760"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true when the registrant is a shell company as defined in Rule 12b-2 of the Exchange Act.",
        "label": "Entity Shell Company"
       }
      }
     },
     "localname": "EntityShellCompany",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntitySmallBusiness": {
     "auth_ref": [
      "r760"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicates that the company is a Smaller Reporting Company (SRC).",
        "label": "Entity Small Business"
       }
      }
     },
     "localname": "EntitySmallBusiness",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntityTaxIdentificationNumber": {
     "auth_ref": [
      "r760"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.",
        "label": "Entity Tax Identification Number"
       }
      }
     },
     "localname": "EntityTaxIdentificationNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "employerIdItemType"
    },
    "dei_LocalPhoneNumber": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Local phone number for entity.",
        "label": "Local Phone Number"
       }
      }
     },
     "localname": "LocalPhoneNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_Security12bTitle": {
     "auth_ref": [
      "r759"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Title of a 12(b) registered security.",
        "label": "Title of 12(b) Security"
       }
      }
     },
     "localname": "Security12bTitle",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "securityTitleItemType"
    },
    "dei_SecurityExchangeName": {
     "auth_ref": [
      "r761"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of the Exchange on which a security is registered.",
        "label": "Security Exchange Name"
       }
      }
     },
     "localname": "SecurityExchangeName",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "edgarExchangeCodeItemType"
    },
    "dei_TradingSymbol": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Trading symbol of an instrument as listed on an exchange.",
        "label": "Trading Symbol"
       }
      }
     },
     "localname": "TradingSymbol",
     "nsuri": "http://xbrl.sec.gov/dei/2021q4",
     "presentation": [
      "http://www.fsbwa.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "tradingSymbolItemType"
    },
    "fsbw_AccountingChangesAndErrorCorrectionPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy relating to accounting changes and error correction.",
        "label": "Accounting Changes and Error Correction [Policy Text Block]",
        "terseLabel": "Error Corrections"
       }
      }
     },
     "localname": "AccountingChangesAndErrorCorrectionPolicyTextBlock",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "fsbw_AccruedInterestReceivableFairValueDisclosure": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accrued Interest Receivable, Fair Value Disclosure",
        "label": "Accrued Interest Receivable, Fair Value Disclosure",
        "terseLabel": "Accrued interest receivable"
       }
      }
     },
     "localname": "AccruedInterestReceivableFairValueDisclosure",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_AllowanceForCreditLossNet": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of net allowance for credit loss.",
        "label": "Allowance For Credit Loss Net",
        "terseLabel": "Total"
       }
      }
     },
     "localname": "AllowanceForCreditLossNet",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_AllowanceForCreditLossesOnUnfundedLoanCommitments": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of allowance for credit losses on unfunded loan commitments.",
        "label": "Allowance For Credit Losses On Unfunded Loan Commitments",
        "terseLabel": "Allowance for unfunded loan commitments",
        "verboseLabel": "Allowance for credit losses on unfunded loan commitments"
       }
      }
     },
     "localname": "AllowanceForCreditLossesOnUnfundedLoanCommitments",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_AllowanceForLoanAndLeaseLossesLoansSoldPercentageOfOutstandingCreditEnhancement": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the allowance for loan and lease losses, loans sold, percentage of outstanding credit enhancement.",
        "label": "Allowance for Loan and Lease Losses, Loans Sold, Percentage of Outstanding Credit Enhancement",
        "terseLabel": "Holdback as a percentage of outstanding CE"
       }
      }
     },
     "localname": "AllowanceForLoanAndLeaseLossesLoansSoldPercentageOfOutstandingCreditEnhancement",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_AnchorBancorpMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information pertaining to Anchor Bancorp.",
        "label": "Anchor Bancorp"
       }
      }
     },
     "localname": "AnchorBancorpMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_ApplicationOfNewAccountingGuidance": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy pertaining to the application of new accounting guidance that may impact the entity's financial reporting.",
        "label": "Application of New Accounting Guidance",
        "terseLabel": "Application of New Accounting Guidance in 2022"
       }
      }
     },
     "localname": "ApplicationOfNewAccountingGuidance",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "fsbw_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsNumber": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Number",
        "label": "Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Number",
        "terseLabel": "Available-for-sale securities with unrealized losses of less than one year"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsNumber",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "fsbw_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionMoreThanTwelveMonthsNumber": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Available-for-sale Securities, Continuous Unrealized Loss Position, More Than Twelve Months, Number",
        "label": "Available for sale Securities Continuous Unrealized Loss Position More Than Twelve Months Number",
        "terseLabel": "Available-for-sale securities with unrealized losses of more than one year"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesContinuousUnrealizedLossPositionMoreThanTwelveMonthsNumber",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "fsbw_BankOfAmericaMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This member stands for the details pertaining to Bank of America.",
        "label": "Bank of America"
       }
      }
     },
     "localname": "BankOfAmericaMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_CashDueFromBanksAndInterestBearingDepositsAtOtherFinancialInstitutionsFairValueDisclosure": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cash, due from banks, and interest-bearing deposits at other financial institutions, fair value disclosure",
        "label": "Cash, Due from Banks, and Interest-Bearing Deposits at Other Financial Institutions, Fair Value Disclosure",
        "terseLabel": "Cash and cash equivalents"
       }
      }
     },
     "localname": "CashDueFromBanksAndInterestBearingDepositsAtOtherFinancialInstitutionsFairValueDisclosure",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_ChangeOfControlAgreementExecutivePaymentPeriodFollowingChangeInControl": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Change of Control Agreement, Executive Payment, Period Following Change in Control",
        "label": "Change of Control Agreement, Executive Payment, Period Following Change in Control",
        "terseLabel": "Change of control agreement, executive payment, period following change in control (in months)"
       }
      }
     },
     "localname": "ChangeOfControlAgreementExecutivePaymentPeriodFollowingChangeInControl",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "fsbw_ChangeOfControlAgreementExecutivePaymentPeriodPriorToChangeInControl": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Change of Control Agreement, Executive Payment, Period Prior to Change in Control",
        "label": "Change of Control Agreement, Executive Payment, Period Prior to Change in Control",
        "terseLabel": "Change of control agreement, executive payment, period prior to change in control (in months)"
       }
      }
     },
     "localname": "ChangeOfControlAgreementExecutivePaymentPeriodPriorToChangeInControl",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "fsbw_ChangeOfControlAgreementNoticeRequiredToCancelAgreementPeriod": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Change of Control Agreement, Notice Required to Cancel Agreement, Period",
        "label": "Change of Control Agreement, Notice Required to Cancel Agreement, Period",
        "terseLabel": "Change of control agreement, notice required to cancel agreement (in months)"
       }
      }
     },
     "localname": "ChangeOfControlAgreementNoticeRequiredToCancelAgreementPeriod",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "fsbw_ChangeOfControlAgreementPeriodOfBaseCompensationDisbursedAsLumpSumPayment": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Change of Control Agreement, Period of Base Compensation Disbursed as Lump Sum Payment",
        "label": "Change of Control Agreement, Period of Base Compensation Disbursed as Lump Sum Payment",
        "terseLabel": "Change of control agreement, period of base compensation disbursed as lump sum payment (in months)"
       }
      }
     },
     "localname": "ChangeOfControlAgreementPeriodOfBaseCompensationDisbursedAsLumpSumPayment",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "fsbw_CollateralAlreadyPostedCarryingValue": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The carrying value of collateral already posted.",
        "label": "Collateral Already Posted, Carrying Value",
        "terseLabel": "Carrying value of collateral already posted"
       }
      }
     },
     "localname": "CollateralAlreadyPostedCarryingValue",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesCreditRiskRelatedContingentFeaturesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_CommercialAndConsumerBankingMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This member stands for commercial and consumer banking.",
        "label": "Commercial and Consumer Banking"
       }
      }
     },
     "localname": "CommercialAndConsumerBankingMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_CommercialAndIndustrialMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This member stands for commercial and industrial.",
        "label": "Commercial and industrial"
       }
      }
     },
     "localname": "CommercialAndIndustrialMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_ConsumerIndirectHomeImprovementLoansMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "-- None. No documentation exists for this element. --",
        "label": "Indirect home improvement"
       }
      }
     },
     "localname": "ConsumerIndirectHomeImprovementLoansMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_ConsumerLoansMarineLoanFinancingReceivableMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Consumer Loans Marine Loan Financing Receivable [Member]",
        "label": "Marine"
       }
      }
     },
     "localname": "ConsumerLoansMarineLoanFinancingReceivableMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_ConsumerLoansOtherMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Consumer loans not categorized elsewhere.",
        "label": "Other consumer loans"
       }
      }
     },
     "localname": "ConsumerLoansOtherMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_CreditQualityIndicatorsPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Credit Quality Indicators",
        "label": "Credit Quality Indicators [Policy Text Block]",
        "terseLabel": "Credit Quality Indicators"
       }
      }
     },
     "localname": "CreditQualityIndicatorsPolicyTextBlock",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "fsbw_CumulativeAmountOfFairValueHedgingAdjustmentIncludedInCarryingAmountOfHedgedAssetsLiabilities": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of cumulative amount of fair value hedging adjustment included in carrying amount of hedged assets (liabilities).",
        "label": "Cumulative Amount Of Fair Value Hedging Adjustment Included in Carrying Amount of Hedged Assets/(Liabilities)",
        "terseLabel": "Cumulative Amount of Fair Value Hedging Adjustment Included in Carrying Amount of the Hedged Assets/(Liabilities)"
       }
      }
     },
     "localname": "CumulativeAmountOfFairValueHedgingAdjustmentIncludedInCarryingAmountOfHedgedAssetsLiabilities",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesCumulativeBasisAdjustmentForFairValueHedgesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_DebitCardInterchangeFeesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Debit card interchange fees.",
        "label": "Debit Card Interchange Fees"
       }
      }
     },
     "localname": "DebitCardInterchangeFeesMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomersDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_DebtSecuritiesAllowanceForCreditLossesExcludingAccruedInterest": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of allowance for credit losses excluding accrued interest on debt securities.",
        "label": "Debt Securities, Allowance For Credit Losses Excluding Accrued Interest",
        "terseLabel": "Allowance for credit losses"
       }
      }
     },
     "localname": "DebtSecuritiesAllowanceForCreditLossesExcludingAccruedInterest",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (available for sale and held-to-maturity), in continuous loss position for 12 months or longer.",
        "label": "Debt Securities, Available for Sale and Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss",
        "negatedTerseLabel": "Unrealized loss position, 12 Months or Longer, Unrealized Losses"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPosition12MonthsOrLongerFairValue": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails": {
       "order": 1.0,
       "parentTag": "fsbw_DebtSecuritiesAvailableForSaleAndHeldToMaturityUnrealizedLossPositionFairValue",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (available for sale and held-to-maturity), in continuous unrealized loss position for less than 12 months.",
        "label": "Debt Securities, Available for Sale and Held to Maturity Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value",
        "terseLabel": "Total securities, Unrealized loss position, Fair Value, 12 Months or Longer"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPosition12MonthsOrLongerFairValue",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (available for sale held-to-maturity), in continuous loss position for less than 12 months.",
        "label": "Debt Securities, Available for Sale and Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss",
        "negatedTerseLabel": "Unrealized loss position, Less than 12 Months, Unrealized Losses"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPositionLessThan12MonthsFairValue": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails": {
       "order": 2.0,
       "parentTag": "fsbw_DebtSecuritiesAvailableForSaleAndHeldToMaturityUnrealizedLossPositionFairValue",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (available for sale and held-to-maturity) in continuous unrealized loss position for less than 12 months.",
        "label": "Debt Securities, Available for Sale and Held-to-maturity Continuous Unrealized Loss Position, Less than 12 Months, Fair Value",
        "terseLabel": "Total securities, Unrealized loss position, Fair Value, Less than 12 Months"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPositionLessThan12MonthsFairValue",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_DebtSecuritiesAvailableForSaleAndHeldToMaturityUnrealizedLossPositionAccumulatedLoss": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (available for sale and held-to-maturity), in unrealized loss position.",
        "label": "Debt Securities, Available for Sale and Held-to-maturity, Unrealized Loss Position, Accumulated Loss",
        "negatedLabel": "Unrealized loss position, Unrealized Losses"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleAndHeldToMaturityUnrealizedLossPositionAccumulatedLoss",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_DebtSecuritiesAvailableForSaleAndHeldToMaturityUnrealizedLossPositionFairValue": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (available for sale held-to-maturity), in unrealized loss position.",
        "label": "Debt Securities, Available for Sale and Held-to-maturity, Unrealized Loss Position, Fair Value",
        "totalLabel": "Total securities, Unrealized loss position, Fair Value"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleAndHeldToMaturityUnrealizedLossPositionFairValue",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_DenominatorShownAsActual": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "n/a",
        "label": "Denominator (shown as actual):"
       }
      }
     },
     "localname": "DenominatorShownAsActual",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareScheduleOfEarningsPerShareBasicAndDilutedDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "fsbw_DepositLiabilitiesCollateralRequirement": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Deposit Liabilities, Collateral Requirement",
        "label": "Deposit Liabilities, Collateral Requirement",
        "terseLabel": "Collateral requirement"
       }
      }
     },
     "localname": "DepositLiabilitiesCollateralRequirement",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_DepositServiceAndAccountMaintenanceFeesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information pertaining to deposit service and account maintenance fee.",
        "label": "Deposit service and account maintenance fees"
       }
      }
     },
     "localname": "DepositServiceAndAccountMaintenanceFeesMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomersDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_DepositsEscrowedAccounts": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails": {
       "order": 8.0,
       "parentTag": "us-gaap_Deposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Deposits, Escrowed Accounts",
        "label": "Deposits, Escrowed Accounts",
        "terseLabel": "Escrow accounts related to mortgages serviced"
       }
      }
     },
     "localname": "DepositsEscrowedAccounts",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_DepositsInterestBearingCheckingBalancesReclassifiedToNonInterestBearingCheckingBalances": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of interest bearing checking balances reclassified to non-interest bearing checking balances for comparative purposes.",
        "label": "Deposits, Interest Bearing Checking Balances Reclassified To Non-interest Bearing Checking Balances",
        "terseLabel": "Interest-bearing to noninterest-bearing due to reclass"
       }
      }
     },
     "localname": "DepositsInterestBearingCheckingBalancesReclassifiedToNonInterestBearingCheckingBalances",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_DepositsMoneyMarketDepositsBrokeredDeposits": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of deposits in accounts that offer many of the same services as checking accounts although transactions may be somewhat more limited, share some of the characteristics of a money market fund and are insured by the Federal government, also known as money market accounts placed by or through the assistance of a deposit broker",
        "label": "Deposits, Money Market Deposits, Brokered Deposits",
        "terseLabel": "Deposits, money market deposits, brokered deposits"
       }
      }
     },
     "localname": "DepositsMoneyMarketDepositsBrokeredDeposits",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_DerivativeHedgingAmortizedCostBasisOfClosedPortfolios": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amortized cost of closed portfolio used in the hedging relationships.",
        "label": "Derivative Hedging, Amortized Cost Basis Of Closed Portfolios",
        "terseLabel": "Amortized cost basis of closed portfolios used in hedging relationships"
       }
      }
     },
     "localname": "DerivativeHedgingAmortizedCostBasisOfClosedPortfolios",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesCumulativeBasisAdjustmentForFairValueHedgesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_DirectorExcludingCeoMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Pertaining to Directors but excluding the CEO.",
        "label": "Directors Excluding CEO"
       }
      }
     },
     "localname": "DirectorExcludingCeoMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_DividendsAndUndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareEarningsPerShareBasicAndDilutesDetailsCalc": {
       "order": 2.0,
       "parentTag": "us-gaap_UndistributedEarningsLossAvailableToCommonShareholdersBasic",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of dividends and undistributed earnings (loss) allocated to participating securities for the basic earnings (loss) per share or per unit calculation under the two-class method.",
        "label": "Dividends And Undistributed Earnings (Loss) Allocated To Participating Securities Basic",
        "negatedLabel": "Dividends and undistributed earnings allocated to participating securities"
       }
      }
     },
     "localname": "DividendsAndUndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareScheduleOfEarningsPerShareBasicAndDilutedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_EmployeeStockOwnershipPlanESOPRequisiteServicePeriod12Months": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Employee Stock Ownership Plan (ESOP), Requisite Service Period, 12 Months",
        "label": "Employee Stock Ownership Plan (ESOP), Requisite Service Period, 12 Months",
        "terseLabel": "Employee stock ownership plan (ESOP), requisite service period (in hours)"
       }
      }
     },
     "localname": "EmployeeStockOwnershipPlanESOPRequisiteServicePeriod12Months",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEmployeeBenefitsNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "fsbw_EmployeeStockOwnershipPlanEsopDebtStructureEmployerLoanAmount": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Employee Stock Ownership Plan (ESOP), Debt Structure, Employer Loan, Amount",
        "label": "Employee Stock Ownership Plan (ESOP), Debt Structure, Employer Loan, Amount"
       }
      }
     },
     "localname": "EmployeeStockOwnershipPlanEsopDebtStructureEmployerLoanAmount",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEmployeeBenefitsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_EmployeeStockOwnershipPlanEsopDebtStructureEmployerLoanInterestRate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Employee Stock Ownership Plan (ESOP), Debt Structure, Employer Loan, Interest Rate",
        "label": "Employee Stock Ownership Plan (ESOP), Debt Structure, Employer Loan, Interest Rate",
        "terseLabel": "Employee stock ownership plan (ESOP), debt structure, employer loan, interest rate"
       }
      }
     },
     "localname": "EmployeeStockOwnershipPlanEsopDebtStructureEmployerLoanInterestRate",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEmployeeBenefitsNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_EmployeeStockOwnershipPlanEsopDebtStructureEmployerLoanTerm": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Employee Stock Ownership Plan (ESOP), Debt Structure, Employer Loan, Term",
        "label": "Employee Stock Ownership Plan (ESOP), Debt Structure, Employer Loan, Term",
        "terseLabel": "Amortization period of ESOP loan"
       }
      }
     },
     "localname": "EmployeeStockOwnershipPlanEsopDebtStructureEmployerLoanTerm",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEmployeeBenefitsNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "fsbw_EmployeeStockOwnershipPlanEsopPrincipalPaymentsFromEsop": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Employee Stock Ownership Plan (ESOP), Principal Payments from ESOP",
        "label": "Employee Stock Ownership Plan (ESOP), Principal Payments from ESOP",
        "terseLabel": "Employee stock ownership plan (ESOP), periodic installment payments from esop, amount paid"
       }
      }
     },
     "localname": "EmployeeStockOwnershipPlanEsopPrincipalPaymentsFromEsop",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEmployeeBenefitsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_EmployeeStockOwnershipPlanEsopRequisiteServicePeriod": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The minimum number of hours of service that an employee is credited with in order to be eligible to participate in the ESOP.",
        "label": "Employee Stock Ownership Plan (ESOP), Requisite Service Period",
        "terseLabel": "Number of hours of service required for participation in ESOP, per first 12 month period (in hours)"
       }
      }
     },
     "localname": "EmployeeStockOwnershipPlanEsopRequisiteServicePeriod",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEmployeeBenefitsNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "fsbw_EmployeeStockOwnershipPlanEsopSharesPurchased": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Employee Stock Ownership Plan (ESOP), Shares Purchased",
        "label": "Employee Stock Ownership Plan (ESOP), Shares Purchased",
        "terseLabel": "Employee stock ownership plan shares purchased"
       }
      }
     },
     "localname": "EmployeeStockOwnershipPlanEsopSharesPurchased",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEmployeeBenefitsNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "fsbw_EmployeeStockOwnershipPlanVestedPercentAfterRequisiteServicePeriodIsMet": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The percentage of vesting of Employee Stock Ownership Plans after requisite service period is met.",
        "label": "Employee Stock Ownership Plan Vested Percent After Requisite Service Period Is Met",
        "terseLabel": "Vesting percentage after requisite service period is met (as a percent)"
       }
      }
     },
     "localname": "EmployeeStockOwnershipPlanVestedPercentAfterRequisiteServicePeriodIsMet",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEmployeeBenefitsNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_EquityIncentivePlan2018Member": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Equity Incentive Plan, 2018",
        "label": "2018 Equity Incentive Plan"
       }
      }
     },
     "localname": "EquityIncentivePlan2018Member",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_EquityOptionAndRestrictedStockMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This member represents contracts conveying rights, but not obligations, to buy or sell a specific quantity of stock at a specified price during a specified period (an American option) or at a specified date (a European option), and stock including a provision that prohibits sale or substantive sale of an equity instrument for a specified period of time or until specified performance conditions are met.",
        "label": "Equity option and restricted stock"
       }
      }
     },
     "localname": "EquityOptionAndRestrictedStockMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_EsopRequisiteServicePeriod": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Minimum period the individual is required to perform services to be fully vested under the Employee Stock Purchase Plan, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "ESOP Requisite Service Period",
        "terseLabel": "Requisite service period (in years)"
       }
      }
     },
     "localname": "EsopRequisiteServicePeriod",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEmployeeBenefitsNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "fsbw_FairValueItemPrimaryCategorizationAxisAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair Value Item, Primary Categorization [Axis] [Axis]",
        "label": "Fair Value Item, Primary Categorization [Axis]"
       }
      }
     },
     "localname": "FairValueItemPrimaryCategorizationAxisAxis",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "fsbw_FairValueItemPrimaryCategorizationAxisDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Domain] for Fair Value Item, Primary Categorization [Axis] [Axis]",
        "label": "Fair Value Item, Primary Categorization [Axis] [Domain]"
       }
      }
     },
     "localname": "FairValueItemPrimaryCategorizationAxisDomain",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_FairValueOffBalanceSheetRiskAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair Value, Off-balance Sheet Risk [Abstract]",
        "label": "SERVICING RIGHTS"
       }
      }
     },
     "localname": "FairValueOffBalanceSheetRiskAbstract",
     "nsuri": "http://www.fsbwa.com/20220630",
     "xbrltype": "stringItemType"
    },
    "fsbw_FederalHomeLoanBankFirstLossAccountEstablished": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Federal Home Loan Bank, First Loss Account Established",
        "label": "Federal Home Loan Bank, First Loss Account Established"
       }
      }
     },
     "localname": "FederalHomeLoanBankFirstLossAccountEstablished",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_FederalHomeLoanBankNumberOfSecuritiesPledged": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Federal Home Loan Bank, Number of Securities Pledged",
        "label": "Federal Home Loan Bank, Number of Securities Pledged",
        "terseLabel": "Number of securities pledged and held at FHLB"
       }
      }
     },
     "localname": "FederalHomeLoanBankNumberOfSecuritiesPledged",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "fsbw_FederalHomeLoanBankRecourseObligation": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Federal Home Loan Bank, Recourse Obligation",
        "label": "Federal Home Loan Bank, Recourse Obligation",
        "terseLabel": "Bank recourse obligation"
       }
      }
     },
     "localname": "FederalHomeLoanBankRecourseObligation",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_FederalHomeLoanBankRecourseObligationPercentageOfLoansOutstanding": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the federal home loan bank, recourse obligation, percentage of loans outstanding.",
        "label": "Federal Home Loan Bank, Recourse Obligation, Percentage of Loans Outstanding",
        "terseLabel": "Bank recourse obligation, percentage of loans outstanding"
       }
      }
     },
     "localname": "FederalHomeLoanBankRecourseObligationPercentageOfLoansOutstanding",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_FinancingReceivableNonAccrualWithAllowanceForCreditLosses": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of financing receivable on non accrual status with allowance for credit loss.",
        "label": "Financing Receivable Non Accrual, With Allowance for Credit Losses",
        "terseLabel": "Nonaccrual with Allowance for Credit Losses"
       }
      }
     },
     "localname": "FinancingReceivableNonAccrualWithAllowanceForCreditLosses",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFour": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_FiniteLivedIntangibleAssetsNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of amortization for asset, excluding financial asset and goodwill, lacking physical substance with finite life expected to be recognized after fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Finite Lived Intangible Assets Amortization Expense After Year Four",
        "terseLabel": "Thereafter"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFour",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_FirstSecurityBankMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents information pertaining to the 1st Security Bank subsidiary.",
        "label": "Bank"
       }
      }
     },
     "localname": "FirstSecurityBankMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRegulatoryCapitalRegulatoryCapitalRatiosPolicyDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_ForwardTbaMortgageBackedSecuritiesCommitmentAssetFairValueDisclosure": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of forward sale commitment asset relative to TBA mortgage-backed securities at fair value.",
        "label": "Forward TBA Mortgage Backed Securities Commitment Asset, Fair Value Disclosure",
        "terseLabel": "Forward TBA mortgage-backed securities"
       }
      }
     },
     "localname": "ForwardTbaMortgageBackedSecuritiesCommitmentAssetFairValueDisclosure",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_ForwardTbaMortgageBackedSecuritiesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents information pertaining to forward TBA mortgage-backed securities.",
        "label": "Forward TBA mortgage backed securities"
       }
      }
     },
     "localname": "ForwardTbaMortgageBackedSecuritiesMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_GainLossOnChangeInFairValueOfNonhedgingDerivatives": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of gain (loss) on change in fair value of the nonhedging derivatives.",
        "label": "Gain (Loss) On Change In Fair Value of the Nonhedging Derivatives",
        "terseLabel": "Changes in the fair value of the non hedging derivatives"
       }
      }
     },
     "localname": "GainLossOnChangeInFairValueOfNonhedgingDerivatives",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_GainLossOnSaleOfLoansHeldForSale": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 7.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of gain or loss on the sale of loans held for sale.",
        "label": "Gain Loss On Sale Of Loans Held For Sale",
        "negatedLabel": "Gain on sale of loans held for sale"
       }
      }
     },
     "localname": "GainLossOnSaleOfLoansHeldForSale",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_GainLossOnSaleOfPortfolioLoans": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 8.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of gain or loss on the sale of portfolio loans.",
        "label": "Gain Loss On Sale Of Portfolio Loans",
        "negatedLabel": "Gain on sale of portfolio loans"
       }
      }
     },
     "localname": "GainLossOnSaleOfPortfolioLoans",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_HedgedAssetsLiabilitiesCarryingAmount": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The carrying amount of hedged assets (liabilities).",
        "label": "Hedged Assets (Liabilities), Carrying Amount",
        "terseLabel": "Carrying Amount of the Hedged Assets/(Liabilities)"
       }
      }
     },
     "localname": "HedgedAssetsLiabilitiesCarryingAmount",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesCumulativeBasisAdjustmentForFairValueHedgesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsNumber": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Held-to maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Number",
        "label": "Held To Maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Number",
        "terseLabel": "Held-to maturity securities with unrealized losses of less than one year"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsNumber",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "fsbw_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionMoreThanTwelveMonthsNumber": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Held to maturity Securities, Continuous Unrealized Loss Position, More Than Twelve Months, Number",
        "label": "Held to Maturity Securities Continuous Unrealized Loss Position More Than Twelve Months Number",
        "terseLabel": "Held-to maturity securities with unrealized losses of more than one year"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesContinuousUnrealizedLossPositionMoreThanTwelveMonthsNumber",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "fsbw_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionNumber": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Held to maturity Securities, Continuous Unrealized Loss Position, Number",
        "label": "Held to Maturity Securities Continuous Unrealized Loss Position Number",
        "terseLabel": "Held-to maturity securities with unrealized losses"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesContinuousUnrealizedLossPositionNumber",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "fsbw_HomeLendingMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Home Lending [Member]",
        "label": "Home Lending"
       }
      }
     },
     "localname": "HomeLendingMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_ImpairedFinancingReceivableRelatedAllowanceAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "n/a",
        "label": "Impaired Financing Receivable Related Allowance Abstract"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableRelatedAllowanceAbstract",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "fsbw_ImpairedFinancingReceivableWithNoRelatedAllowance": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_ImpairedFinancingReceivableRelatedAllowance",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of allowance for credit losses related to recorded investment for which there is no related allowance.",
        "label": "Impaired Financing Receivable With No Related Allowance",
        "terseLabel": "Related Allowance, with no related allowance recorded"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableWithNoRelatedAllowance",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_ImpairedFinancingReceivableWithRelatedAllowance": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_ImpairedFinancingReceivableRelatedAllowance",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of allowance for credit losses related to recorded investment for which there is a related allowance.",
        "label": "Impaired Financing Receivable With Related Allowance",
        "terseLabel": "Related Allowance, with an allowance recorded"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableWithRelatedAllowance",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_ImpairedLoansCollateral": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of amortized cost basis of collateral dependent impaired loans by class of loans .",
        "label": "Impaired Loans Collateral",
        "terseLabel": "Amortized cost basis of collateral dependent impaired loans"
       }
      }
     },
     "localname": "ImpairedLoansCollateral",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_ImpairedLoansMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Impaired Loans [Member]",
        "label": "Impaired Loans"
       }
      }
     },
     "localname": "ImpairedLoansMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_IndependentDirectorMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information pertaining to an independent director.",
        "label": "Independent Director"
       }
      }
     },
     "localname": "IndependentDirectorMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFour": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payments for operating lease, due after fourth fiscal year following latest fiscal year.",
        "label": "Lessee, Operating Lease, Liability, Payments, Due after Year Four",
        "terseLabel": "Thereafter"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFour",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_LoanPortfolioSegmentPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loan Portfolio Segment",
        "label": "Loan Portfolio Segment [Policy Text Block]",
        "terseLabel": "Loan Portfolio Segment"
       }
      }
     },
     "localname": "LoanPortfolioSegmentPolicyTextBlock",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "fsbw_LoansIndividuallyEvaluatedFairValueDisclosure": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The fair value of loans individually evaluated.",
        "label": "Loans Individually Evaluated, Fair Value Disclosure",
        "terseLabel": "Loans individually evaluated"
       }
      }
     },
     "localname": "LoansIndividuallyEvaluatedFairValueDisclosure",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsLoansIndividuallyEvaluatedOreoAndServicingRightsOnNonRecurringBasisDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_LoansReceivableDiscountsOnAcquiredLoans": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of net discounts on acquired loans receivables.",
        "label": "Loans Receivable, Discounts On Acquired Loans",
        "terseLabel": "Net discounts on acquired loans"
       }
      }
     },
     "localname": "LoansReceivableDiscountsOnAcquiredLoans",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_LoansReceivableNumberOfDaysDelinquentToDiscontinueInterestAccrualMinimum": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The minimum number of days past due for a loan receivable to have interest accrual discontinued.",
        "label": "Loans Receivable Number Of Days Delinquent To Discontinue Interest Accrual Minimum",
        "terseLabel": "Minimum term for accrual of interest on loans to be discontinued"
       }
      }
     },
     "localname": "LoansReceivableNumberOfDaysDelinquentToDiscontinueInterestAccrualMinimum",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "fsbw_MandatoryAndBestEffortForwardCommitmentAssetWithInvestorsFairValueDisclosure": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of the mandatory and best effort forward commitments asset with investors at fair value.",
        "label": "Mandatory And Best Effort Forward Commitment Asset With Investors, Fair Value Disclosure",
        "terseLabel": "Mandatory and best effort forward commitments with investors"
       }
      }
     },
     "localname": "MandatoryAndBestEffortForwardCommitmentAssetWithInvestorsFairValueDisclosure",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_MandatoryAndBestEffortForwardCommitmentsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This member stands for Mandatory and Best Effort Forward Commitments.",
        "label": "Mandatory and best effort forward commitments"
       }
      }
     },
     "localname": "MandatoryAndBestEffortForwardCommitmentsMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_MandatoryAndBestEffortForwardCommitmentsWithInvestorsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents information pertaining to mandatory and best effort forward  commitments with investors.",
        "label": "Mandatory and best effort forward commitments with investors"
       }
      }
     },
     "localname": "MandatoryAndBestEffortForwardCommitmentsWithInvestorsMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_MortgageCommercialAndConsumerServicingRightsFairValueDisclosure": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Mortgage commercial and consumer servicing rights fair value disclosure.",
        "label": "Mortgage, Commercial and Consumer Servicing Rights, Fair Value Disclosure",
        "terseLabel": "Servicing rights, held at lower of cost or fair value"
       }
      }
     },
     "localname": "MortgageCommercialAndConsumerServicingRightsFairValueDisclosure",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_MortgageLoansHeldForSaleMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This member stands for mortgage loans held for sale.",
        "label": "Mortgage loans held for sale"
       }
      }
     },
     "localname": "MortgageLoansHeldForSaleMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_MortgageServicingRightsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This member stands for mortgage servicing rights.",
        "label": "Mortgage servicing rights."
       }
      }
     },
     "localname": "MortgageServicingRightsMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsTables",
      "http://www.fsbwa.com/role/DisclosureServicingRightsValuationAssumptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_MultiFamilyRealEstateLoansMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "-- None. No documentation exists for this element. --",
        "label": "Multi-family"
       }
      }
     },
     "localname": "MultiFamilyRealEstateLoansMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_NonAccrualFinancingReceivablesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Non Accrual Financing Receivables [Member]",
        "label": "Non-Accrual"
       }
      }
     },
     "localname": "NonAccrualFinancingReceivablesMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_NumberOfAdministrativeOfficesThatAcceptDeposits": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The number of administrative offices that accept deposits.",
        "label": "Number Of Administrative Offices That Accept Deposits",
        "terseLabel": "Number of administrative offices that originates loans and accept deposits"
       }
      }
     },
     "localname": "NumberOfAdministrativeOfficesThatAcceptDeposits",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "fsbw_NumberOfBankBranches": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of Bank Branches",
        "label": "Number of Bank Branches",
        "terseLabel": "Number of bank branches"
       }
      }
     },
     "localname": "NumberOfBankBranches",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesDetails",
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "fsbw_NumberOfLoanPortfolioSegments": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of Loan Portfolio Segments",
        "label": "Number of Loan Portfolio Segments",
        "terseLabel": "Number of loan portfolio segments"
       }
      }
     },
     "localname": "NumberOfLoanPortfolioSegments",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "fsbw_NumberOfLoansAccruingInterest": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The number of loans that are accruing interest.",
        "label": "Number Of Loans Accruing Interest"
       }
      }
     },
     "localname": "NumberOfLoansAccruingInterest",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "fsbw_NumberOfTdrsIncurringDefaultWithinTwelveMonthsOfRestructure": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the number of TDRs which incurred a payment default within twelve months of the restructure date.",
        "label": "Number Of TDRs Incurring Default Within Twelve Months Of Restructure",
        "terseLabel": "Number of TDRs which incurred payment default"
       }
      }
     },
     "localname": "NumberOfTdrsIncurringDefaultWithinTwelveMonthsOfRestructure",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "fsbw_NumberOfTroubledDebtRestructuredLoans": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "No definition available.",
        "label": "Number Of Troubled Debt Restructured Loans",
        "terseLabel": "Number of TDR loans"
       }
      }
     },
     "localname": "NumberOfTroubledDebtRestructuredLoans",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "fsbw_NumberOfWarehouseLendingDivisions": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The number of warehouse lending divisions in the company.",
        "label": "Number Of Warehouse Lending Divisions",
        "terseLabel": "Number of warehouse lending divisions"
       }
      }
     },
     "localname": "NumberOfWarehouseLendingDivisions",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "fsbw_NumeratorInThousands": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "n/a",
        "label": "Numerator (in thousands):"
       }
      }
     },
     "localname": "NumeratorInThousands",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareScheduleOfEarningsPerShareBasicAndDilutedDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "fsbw_OfficersAndEmployeesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information pertaining to persons serving as officers of the entity and to employees of the entity.",
        "label": "Officers And Employees"
       }
      }
     },
     "localname": "OfficersAndEmployeesMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_OneToFourFamilyRealEstateLoansMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "-- None. No documentation exists for this element. --",
        "label": "One-to-four-family"
       }
      }
     },
     "localname": "OneToFourFamilyRealEstateLoansMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_OtherRealEstateOwned": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 12.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of other real estate owned not separately identified elsewhere.",
        "label": "Other Real Estate Owned.",
        "terseLabel": "Other real estate owned (\"OREO\")",
        "verboseLabel": "Other real estate owned"
       }
      }
     },
     "localname": "OtherRealEstateOwned",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsLoansIndividuallyEvaluatedOreoAndServicingRightsOnNonRecurringBasisDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_OtherRealEstateOwnedCapitalizedCosts": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of other real estate owned capitalized costs.",
        "label": "Other real estate owned, capitalized costs",
        "verboseLabel": "Additions"
       }
      }
     },
     "localname": "OtherRealEstateOwnedCapitalizedCosts",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureOtherRealEstateOwnedOreoActivityRelatedToOreoDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_OtherRealEstateOwnedDispositionOfAssets": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of gross proceeds from the disposition of other real estate owned (\"OREO\").",
        "label": "Other Real Estate Owned Disposition of Assets",
        "negatedTerseLabel": "Gross proceeds from sale of OREO"
       }
      }
     },
     "localname": "OtherRealEstateOwnedDispositionOfAssets",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureOtherRealEstateOwnedOreoActivityRelatedToOreoDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_OtherRealEstateOwnedMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "OREO",
        "label": "OREO"
       }
      }
     },
     "localname": "OtherRealEstateOwnedMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_OutstandingDelinquenciesOnLoansSoldToFederalHomeLoanBank": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of outstanding delinquencies on loans sold to federal home loan bank.",
        "label": "Outstanding Delinquencies On Loans Sold to Federal Home Loan Bank",
        "terseLabel": "Outstanding delinquencies on loans sold to Federal Home Loan Bank"
       }
      }
     },
     "localname": "OutstandingDelinquenciesOnLoansSoldToFederalHomeLoanBank",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_PacificNorthwestMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Pacific Northwest [Member]",
        "label": "Pacific Northwest"
       }
      }
     },
     "localname": "PacificNorthwestMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_PaymentsForOriginationOfLoansAndPrincipleCollectionsNet": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of cash paid for the origination of loans net of principle collections",
        "label": "Payments for Origination of Loans and Principle Collections Net",
        "negatedLabel": "Portfolio loan originations and principal collections, net"
       }
      }
     },
     "localname": "PaymentsForOriginationOfLoansAndPrincipleCollectionsNet",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_PeriodEndAmountAllocatedTo": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "n/a",
        "label": "Period End Amount Allocated to"
       }
      }
     },
     "localname": "PeriodEndAmountAllocatedTo",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "fsbw_PledgedFinancialInstrumentsNotSeparatelyReportedLoansReceivablePledgedForFederalReserveBankLineOfCredit": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The carrying amount, as of the date of the latest financial statement presented, of loans receivable which are owned but transferred to serve as collateral for the payment of Federal Reserve bank line of credit obligations, and for which the transferee is not permitted to sell or re-pledge them to an unrelated party.",
        "label": "Pledged Financial Instruments Not Separately Reported Loans Receivable Pledged For Federal Reserve Bank Line Of Credit",
        "terseLabel": "Loans that qualify as collateral for Federal Reserve Bank lines of credit"
       }
      }
     },
     "localname": "PledgedFinancialInstrumentsNotSeparatelyReportedLoansReceivablePledgedForFederalReserveBankLineOfCredit",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_ProceedsFromDisbursementsOfStockOptionsExercisedNet": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 7.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of proceeds from disbursements of stock options exercised, net.",
        "label": "Proceeds From (Disbursements) Of Stock Options Exercised, Net",
        "terseLabel": "Proceeds (disbursements) from stock options exercised, net"
       }
      }
     },
     "localname": "ProceedsFromDisbursementsOfStockOptionsExercisedNet",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_PublicDeposits": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Public Deposits",
        "label": "Public Deposits",
        "terseLabel": "Public deposits"
       }
      }
     },
     "localname": "PublicDeposits",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_PugetSoundMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Puget Sound [Member]",
        "label": "Puget Sound"
       }
      }
     },
     "localname": "PugetSoundMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_RealEstateLoanPortfolioSegmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Portfolio segment of the company's total financing receivables related to real estate loans.",
        "label": "REAL ESTATE LOANS"
       }
      }
     },
     "localname": "RealEstateLoanPortfolioSegmentMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_RealEstateOwnedHoldingCosts": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Real Estate Owned, Holding Costs",
        "label": "Real Estate Owned, Holding Costs",
        "terseLabel": "Holding costs"
       }
      }
     },
     "localname": "RealEstateOwnedHoldingCosts",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureOtherRealEstateOwnedOreoNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_RetailDepositMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Retail Deposit [Member]",
        "label": "Retail Deposit"
       }
      }
     },
     "localname": "RetailDepositMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_RetentionOfMortgageServicingRightsFromLoanSales": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Retention of mortgage servicing rights from loan sales.",
        "label": "Retention of Mortgage Servicing Rights from Loan Sales",
        "terseLabel": "Retention in gross mortgage servicing rights from loan sales"
       }
      }
     },
     "localname": "RetentionOfMortgageServicingRightsFromLoanSales",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_RightOfUseAssetObtainedInExchangeForLeaseLiability": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase in right-of-use asset obtained in exchange for lease liability.",
        "label": "Right Of Use Asset Obtained In Exchange For Lease Liability",
        "terseLabel": "Right-of-use assets in exchange for lease liabilities"
       }
      }
     },
     "localname": "RightOfUseAssetObtainedInExchangeForLeaseLiability",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_SaleOfLoansToFederalHomeLoanBank": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of sale of loans to federal home loan bank.",
        "label": "Sale of Loans to Federal Home Loan Bank",
        "terseLabel": "Amount of loans sold to FHLB"
       }
      }
     },
     "localname": "SaleOfLoansToFederalHomeLoanBank",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_ScheduleOfAccountingPoliciesLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "[Line Items] for Schedule of Accounting Policies [Table]",
        "label": "Schedule of Accounting Policies [Line Items]"
       }
      }
     },
     "localname": "ScheduleOfAccountingPoliciesLineItems",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesDetails",
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesErrorCorrectionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "fsbw_ScheduleOfAccountingPoliciesTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule of Accounting Policies [Table]",
        "label": "Schedule of Accounting Policies [Table]"
       }
      }
     },
     "localname": "ScheduleOfAccountingPoliciesTable",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesDetails",
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesErrorCorrectionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "fsbw_ScheduleOfCollateralDependentImpairedLoansTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of collateral dependent impaired loans by class of loans.",
        "label": "Schedule of Collateral Dependent Impaired Loans [Table Text Block]",
        "terseLabel": "Schedule of amortized cost basis of collateral dependent impaired loans"
       }
      }
     },
     "localname": "ScheduleOfCollateralDependentImpairedLoansTableTextBlock",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "fsbw_ScheduleOfDepositLiabilitiesTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure for schedule of deposit liabilities.",
        "label": "Schedule of Deposit Liabilities [Table Text Block]",
        "terseLabel": "Schedule of Deposit Liabilities"
       }
      }
     },
     "localname": "ScheduleOfDepositLiabilitiesTableTextBlock",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "fsbw_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsByMajorClassTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of amortizable finite-lived intangible assets, in total and by major class, including the gross carrying amount and accumulated amortization, and indefinite-lived intangible assets not subject to amortization, excluding goodwill, in total and by major class. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.",
        "label": "Schedule Of Finite Lived And Indefinite Lived Intangible Assets By Major Class Table Text Block",
        "terseLabel": "Schedule of changes in other intangible assets"
       }
      }
     },
     "localname": "ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsByMajorClassTableTextBlock",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "fsbw_ScheduleOfInterestExpenseByDepositCategoryTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of summary of interest expense by deposit category.",
        "label": "Schedule of Interest Expense by Deposit Category [Table Text Block]",
        "terseLabel": "Schedule of Interest Expense by Deposit Category"
       }
      }
     },
     "localname": "ScheduleOfInterestExpenseByDepositCategoryTableTextBlock",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "fsbw_ScheduleOfMaturitiesOfTimeDepositsTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of schedule of maturities of time deposits.",
        "label": "Schedule of Maturities of Time Deposits [Table Text Block]",
        "terseLabel": "Schedule of Maturities of Time Deposits for Future Periods"
       }
      }
     },
     "localname": "ScheduleOfMaturitiesOfTimeDepositsTableTextBlock",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "fsbw_ScheduleOfOutstandingCommitmentsTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of outstanding commitments",
        "label": "Schedule of Outstanding Commitments [Table Text Block]",
        "verboseLabel": "Schedule of Commitments to Extend Credit"
       }
      }
     },
     "localname": "ScheduleOfOutstandingCommitmentsTableTextBlock",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "fsbw_SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsAmountAfter0.5AdverseChangeInDiscountRate": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sensitivity analysis of fair value transferors interests in transferred financial assets amount after 0.5 adverse change in discount rate",
        "label": "Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Amount After 0.5% Adverse Change in Discount Rate",
        "terseLabel": "Fair value MSR, 0.5% Adverse Change"
       }
      }
     },
     "localname": "SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsAmountAfter0.5AdverseChangeInDiscountRate",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsAmountAfter0.5AdverseChangeInNoteRate": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sensitivity analysis of fair value transferors interests in transferred financial assets amount after 0.5 adverse change in note rate.",
        "label": "Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Amount After 0.5% Adverse Change in Note Rate",
        "terseLabel": "Fair value MSR, 0.5% Adverse Change"
       }
      }
     },
     "localname": "SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsAmountAfter0.5AdverseChangeInNoteRate",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsAmountAfter1AdverseChangeInDiscountRate": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sensitivity analysis of fair value transferors interests in transferred financial assets amount after 1 adverse change in discount rate",
        "label": "Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Amount After 1% Adverse Change in Discount Rate",
        "terseLabel": "Fair value MSR, 1.0% Adverse Change"
       }
      }
     },
     "localname": "SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsAmountAfter1AdverseChangeInDiscountRate",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsAmountAfter1AdverseChangeInNoteRate": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sensitivity analysis of fair value transferors interests in transferred financial assets amount after 1 adverse change in note rate",
        "label": "Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Amount After 1% Adverse Change in Note Rate",
        "terseLabel": "Fair value of MSR, 1.0% Adverse Change"
       }
      }
     },
     "localname": "SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsAmountAfter1AdverseChangeInNoteRate",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsConditionalRepaymentRateAfter0.5AdverseChangeInNoteRate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The percentage of sensitivity analysis of fair value transferors interests in transferred financial assets conditional repayment rate after 0.5 adverse change in note rate.",
        "label": "Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Conditional Repayment Rate After 0.5% Adverse Change in Note Rate",
        "terseLabel": "Conditional prepayment rate, 0.5% Adverse Change"
       }
      }
     },
     "localname": "SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsConditionalRepaymentRateAfter0.5AdverseChangeInNoteRate",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsConditionalRepaymentRateAfter1AdverseChangeInNoteRate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The percentage of sensitivity analysis of fair value transferors interests in transferred financial assets conditional repayment rate after 1 adverse change in note rate.",
        "label": "Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Conditional Repayment Rate After 1% Adverse Change in Note Rate",
        "terseLabel": "Conditional prepayment rate, 1.0% Adverse Change"
       }
      }
     },
     "localname": "SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsConditionalRepaymentRateAfter1AdverseChangeInNoteRate",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsDiscountRateAfter0.5AdverseChangeInNoteRate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the sensitivity analysis of fair value transferors interests in transferred financial assets discount rate after 0.5 adverse change in note rate",
        "label": "Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Discount Rate After 0.5% Adverse Change in Note Rate",
        "terseLabel": "Discount rate, 0.5% Adverse Change"
       }
      }
     },
     "localname": "SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsDiscountRateAfter0.5AdverseChangeInNoteRate",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsDiscountRateAfter1AdverseChangeInNoteRate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the sensitivity analysis of fair value transferors interests in transferred financial assets discount rate after 1 adverse change in note rate",
        "label": "Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Discount Rate After 1% Adverse Change in Note Rate",
        "terseLabel": "Discount rate, 1.0% Adverse Change"
       }
      }
     },
     "localname": "SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsDiscountRateAfter1AdverseChangeInNoteRate",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_ServicingAssetAtAmortizedCostImpairmentRecovery": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of servicing asset at amortized cost, impairment (recovery).",
        "label": "Servicing Asset at Amortized Cost, Impairment (Recovery)",
        "negatedTerseLabel": "Impairment of servicing rights"
       }
      }
     },
     "localname": "ServicingAssetAtAmortizedCostImpairmentRecovery",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsServicingRightsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueWeightedAverageRateOfNote": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The percentage of servicing assets and servicing liabilities at fair value assumptions used to estimate fair value weighted average rate of note.",
        "label": "Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Weighted Average Rate of Note",
        "terseLabel": "Weighted average rate of note"
       }
      }
     },
     "localname": "ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueWeightedAverageRateOfNote",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_ServicingLiabilityAtFairValueBasisPointsDropInNoteRateAssumptionOne": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the servicing liability at fair value, basis points drop in note rate, assumption one.",
        "label": "Servicing Liability at Fair Value, Basis Points Drop in Note Rate, Assumption One",
        "terseLabel": "Basis Points Drop in Rate, Assumption One"
       }
      }
     },
     "localname": "ServicingLiabilityAtFairValueBasisPointsDropInNoteRateAssumptionOne",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_ServicingLiabilityAtFairValueBasisPointsDropInNoteRateAssumptionTwo": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the servicing liability at fair value, basis points drop in note rate, assumption two.",
        "label": "Servicing Liability at Fair Value, Basis Points Drop in Note Rate, Assumption Two",
        "terseLabel": "Basis Points Drop in Rate, Assumption Two"
       }
      }
     },
     "localname": "ServicingLiabilityAtFairValueBasisPointsDropInNoteRateAssumptionTwo",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_ServicingLiabilityAtFairValueSingleFamilyMortgageServicingRightsAsAPercentageOfAggregatePortfolioPrincipalBalance": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the servicing liability at fair value single family mortgage servicing rights as a percentage of aggregate portfolio principal balance",
        "label": "Servicing Liability at Fair Value, Single Family Mortgage Servicing Rights as a Percentage of Aggregate Portfolio Principal Balance",
        "terseLabel": "Percentage of MSR"
       }
      }
     },
     "localname": "ServicingLiabilityAtFairValueSingleFamilyMortgageServicingRightsAsAPercentageOfAggregatePortfolioPrincipalBalance",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_ServicingLiabilityAtFairValueSingleFamilyMortgageServicingRightsAsAPercentageOfAggregatePortfolioPrincipalBalanceAfter0.5AdverseChangeInDiscountRate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the servicing liability at fair value single family mortgage servicing rights as a percentage of aggregate portfolio principal balance after 0.5 adverse change in discount rate.",
        "label": "Servicing Liability at Fair Value, Single Family Mortgage Servicing Rights as a Percentage of Aggregate Portfolio Principal Balance, After 0.5% Adverse Change in Discount Rate",
        "terseLabel": "Percentage of MSR, 0.5% Adverse Change"
       }
      }
     },
     "localname": "ServicingLiabilityAtFairValueSingleFamilyMortgageServicingRightsAsAPercentageOfAggregatePortfolioPrincipalBalanceAfter0.5AdverseChangeInDiscountRate",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_ServicingLiabilityAtFairValueSingleFamilyMortgageServicingRightsAsAPercentageOfAggregatePortfolioPrincipalBalanceAfter0.5AdverseChangeInNoteRate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the servicing liability at fair value single family mortgage servicing rights as a percentage of aggregate portfolio principal balance after 0.5 adverse change in note rate",
        "label": "Servicing Liability at Fair Value, Single Family Mortgage Servicing Rights as a Percentage of Aggregate Portfolio Principal Balance, After 0.5% Adverse Change in Note Rate",
        "terseLabel": "Percentage of MSR, 0.5% Adverse Change"
       }
      }
     },
     "localname": "ServicingLiabilityAtFairValueSingleFamilyMortgageServicingRightsAsAPercentageOfAggregatePortfolioPrincipalBalanceAfter0.5AdverseChangeInNoteRate",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_ServicingLiabilityAtFairValueSingleFamilyMortgageServicingRightsAsAPercentageOfAggregatePortfolioPrincipalBalanceAfter1AdverseChangeInDiscountRate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the servicing liability at fair value single family mortgage servicing rights as a percentage of aggregate portfolio principal balance after 1 adverse change in discount rate.",
        "label": "Servicing Liability at Fair Value, Single Family Mortgage Servicing Rights as a Percentage of Aggregate Portfolio Principal Balance, After 1% Adverse Change in Discount Rate",
        "terseLabel": "Percentage of MSR, 1.0% Adverse Change"
       }
      }
     },
     "localname": "ServicingLiabilityAtFairValueSingleFamilyMortgageServicingRightsAsAPercentageOfAggregatePortfolioPrincipalBalanceAfter1AdverseChangeInDiscountRate",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_ServicingLiabilityAtFairValueSingleFamilyMortgageServicingRightsAsAPercentageOfAggregatePortfolioPrincipalBalanceAfter1AdverseChangeInNoteRate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the servicing liability at fair value single family mortgage servicing rights as a percentage of aggregate portfolio principal balance after 1 adverse change in note rate",
        "label": "Servicing Liability at Fair Value, Single Family Mortgage Servicing Rights as a Percentage of Aggregate Portfolio Principal Balance, After 1% Adverse Change in Note Rate",
        "terseLabel": "Percentage of MSR, 1.0% Adverse Change"
       }
      }
     },
     "localname": "ServicingLiabilityAtFairValueSingleFamilyMortgageServicingRightsAsAPercentageOfAggregatePortfolioPrincipalBalanceAfter1AdverseChangeInNoteRate",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_ServicingRights": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The fair value of servicing rights.",
        "label": "Servicing Rights",
        "terseLabel": "Servicing rights."
       }
      }
     },
     "localname": "ServicingRights",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsLoansIndividuallyEvaluatedOreoAndServicingRightsOnNonRecurringBasisDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_ServicingRightsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information related to serving rights.",
        "label": "Servicing rights"
       }
      }
     },
     "localname": "ServicingRightsMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_SeveranceAgreementPeriodOfBaseCompensationDisbursedAsLumpSumPayment": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Severance Agreement, Period of Base Compensation Disbursed as Lump Sum Payment",
        "label": "Severance Agreement, Period of Base Compensation Disbursed as Lump Sum Payment",
        "terseLabel": "Severance agreement, period of base compensation disbursed as lump sum payment (in months)"
       }
      }
     },
     "localname": "SeveranceAgreementPeriodOfBaseCompensationDisbursedAsLumpSumPayment",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "fsbw_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPercentage": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the share-based compensation arrangement by share-based payment award, award vesting percentage.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Percentage",
        "terseLabel": "Annual award vesting percentage"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPercentage",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAggregateIntrinsicValueAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the hare-based compensation arrangement by share-based payment award options aggregate intrinsic value abstract.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Aggregate Intrinsic Value [Abstract]",
        "terseLabel": "Aggregate Intrinsic Value"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAggregateIntrinsicValueAbstract",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "fsbw_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpectedForfeitureRate": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the share-based compensation arrangement by share-based payment award options expected forfeiture rate.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Expected Forfeiture Rate",
        "terseLabel": "Annual forfeiture rate"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpectedForfeitureRate",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpectedForfeitureRateOverContractualTerm": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the share-based compensation arrangement by share -based payment award options expected forfeiture rate over contractual term.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Expected Forfeiture Rate Over Contractual Term",
        "terseLabel": "Expected forfeiture rate over contractual term"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpectedForfeitureRateOverContractualTerm",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "fsbw_ShareBasedCompensationArrangementByShareBasedPaymentAwardWeightedAverageRemainingContractualTermAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the share-based compensation arrangement by share-based payment award weighted average remaining contractual term abstract.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Weighted Average Remaining Contractual Term [Abstract]",
        "terseLabel": "Weighted-Average Remaining Contractual Term In Years"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardWeightedAverageRemainingContractualTermAbstract",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "fsbw_StockOptionsAndRestrictedStockAwardsCompensation": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate amount of noncash, employee remuneration related to stock options and restricted stock awards. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.",
        "label": "Stock Options And Restricted Stock Awards Compensation",
        "terseLabel": "Compensation expense related to stock options and restricted stock awards"
       }
      }
     },
     "localname": "StockOptionsAndRestrictedStockAwardsCompensation",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_SubordinatedDebtGross": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "fsbw_SubordinatedDebtNetOfUnamortizedDebtIssuanceCosts",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Carrying value of the gross amount of subordinated debt including the current and noncurrent portions.",
        "label": "Subordinated Debt Gross",
        "terseLabel": "Principal amount"
       }
      }
     },
     "localname": "SubordinatedDebtGross",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_SubordinatedDebtNetOfUnamortizedDebtIssuanceCosts": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Subordinated Debt, Net of Unamortized Debt Issuance Costs.",
        "label": "Subordinated Debt Net of Unamortized Debt Issuance Costs",
        "totalLabel": "Total subordinated notes less unamortized debt issuance costs"
       }
      }
     },
     "localname": "SubordinatedDebtNetOfUnamortizedDebtIssuanceCosts",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_SupplementalInformationRelatedToOperatingLeasesTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of supplemental information related to operating leases.",
        "label": "Supplemental Information Related To Operating Leases Table Text Block",
        "terseLabel": "Supplemental information related to operating leases"
       }
      }
     },
     "localname": "SupplementalInformationRelatedToOperatingLeasesTableTextBlock",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "fsbw_TimeDepositMaturitiesAfterYearFour": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsMaturitiesOfTimeDepositsForFuturePeriodsDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_TimeDeposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposits maturing after the fourth fiscal year following the latest fiscal year. Time deposits include, but are not limited to, certificates of deposits. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Time Deposit Maturities, after Year Four",
        "terseLabel": "Thereafter"
       }
      }
     },
     "localname": "TimeDepositMaturitiesAfterYearFour",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsMaturitiesOfTimeDepositsForFuturePeriodsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_TimeDeposits250000OrMore": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails": {
       "order": 7.0,
       "parentTag": "us-gaap_Deposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Time Deposits, $250,000 or More",
        "label": "Time Deposits, $250,000 or More",
        "terseLabel": "Certificates of deposit of $250,000 and over"
       }
      }
     },
     "localname": "TimeDeposits250000OrMore",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_TimeDepositsBetween100000And250000": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_Deposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Time Deposits, between $100,000 and $250,000",
        "label": "Time Deposits, between $100,000 and $250,000",
        "terseLabel": "Certificates of deposit of $100,000 through $250,000"
       }
      }
     },
     "localname": "TimeDepositsBetween100000And250000",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_TimeDepositsLessThan100000BrokeredDeposits": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposit liabilities, including certificates of deposit, placed by or through the assistance of a deposit broker, in denominations of less than $100,000.",
        "label": "Time Deposits Less Than 100000 Brokered Deposits",
        "terseLabel": "Certificates of deposits less than 100000 brokered deposits"
       }
      }
     },
     "localname": "TimeDepositsLessThan100000BrokeredDeposits",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "fsbw_UnallocatedMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents information pertaining to unallocated.",
        "label": "Unallocated"
       }
      }
     },
     "localname": "UnallocatedMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_UnearnedEsopSharesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "-- None. No documentation exists for this element. --",
        "label": "Unearned ESOP Shares"
       }
      }
     },
     "localname": "UnearnedEsopSharesMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_WarehouseLendingMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This member stands for warehouse lending.",
        "label": "Warehouse lending"
       }
      }
     },
     "localname": "WarehouseLendingMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_WashingtonPublicDepositProtectionCommissionMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information pertaining to the Washington Public Deposit Protection Commission.",
        "label": "Washington Public Deposit Protection Commission"
       }
      }
     },
     "localname": "WashingtonPublicDepositProtectionCommissionMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "fsbw_WatchMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A category of financing receivables considered to be under watch.",
        "label": "Watch"
       }
      }
     },
     "localname": "WatchMember",
     "nsuri": "http://www.fsbwa.com/20220630",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ChiefExecutiveOfficerMember": {
     "auth_ref": [
      "r189"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "CEO"
       }
      }
     },
     "localname": "ChiefExecutiveOfficerMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ConsolidatedEntitiesAxis": {
     "auth_ref": [
      "r103",
      "r350",
      "r354",
      "r359",
      "r459",
      "r460",
      "r465",
      "r466",
      "r580",
      "r756"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Consolidated Entities [Axis]"
       }
      }
     },
     "localname": "ConsolidatedEntitiesAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRegulatoryCapitalRegulatoryCapitalRatiosPolicyDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_ConsolidatedEntitiesDomain": {
     "auth_ref": [
      "r103",
      "r350",
      "r354",
      "r359",
      "r459",
      "r460",
      "r465",
      "r466",
      "r580",
      "r756"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Consolidated Entities [Domain]"
       }
      }
     },
     "localname": "ConsolidatedEntitiesDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRegulatoryCapitalRegulatoryCapitalRatiosPolicyDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_CounterpartyNameAxis": {
     "auth_ref": [
      "r37",
      "r40",
      "r101",
      "r102",
      "r362",
      "r369"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Counterparty Name [Axis]"
       }
      }
     },
     "localname": "CounterpartyNameAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_CreditRatingStandardPoorsAxis": {
     "auth_ref": [
      "r207",
      "r292",
      "r299",
      "r347",
      "r497"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Credit Rating, Standard &amp; Poor's [Axis]"
       }
      }
     },
     "localname": "CreditRatingStandardPoorsAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAmortizedCostOfDebtDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember": {
     "auth_ref": [
      "r2",
      "r108",
      "r117",
      "r272",
      "r434",
      "r435",
      "r436",
      "r451",
      "r452",
      "r513",
      "r518",
      "r519",
      "r785"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Cumulative Effect, Period of Adoption, Adjusted Balance"
       }
      }
     },
     "localname": "CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember": {
     "auth_ref": [
      "r2",
      "r108",
      "r117",
      "r124",
      "r272",
      "r434",
      "r435",
      "r436",
      "r451",
      "r452",
      "r513",
      "r516",
      "r518",
      "r519",
      "r785"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Cumulative Effect, Period of Adoption, Adjustment"
       }
      }
     },
     "localname": "CumulativeEffectPeriodOfAdoptionAdjustmentMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_CumulativeEffectPeriodOfAdoptionAxis": {
     "auth_ref": [
      "r2",
      "r108",
      "r117",
      "r124",
      "r272",
      "r434",
      "r435",
      "r436",
      "r451",
      "r452",
      "r513",
      "r516",
      "r518",
      "r519",
      "r785"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Cumulative Effect, Period of Adoption [Axis]"
       }
      }
     },
     "localname": "CumulativeEffectPeriodOfAdoptionAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_CumulativeEffectPeriodOfAdoptionDomain": {
     "auth_ref": [
      "r2",
      "r108",
      "r117",
      "r124",
      "r272",
      "r434",
      "r435",
      "r436",
      "r451",
      "r452",
      "r513",
      "r516",
      "r518",
      "r519",
      "r785"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Cumulative Effect, Period of Adoption [Domain]"
       }
      }
     },
     "localname": "CumulativeEffectPeriodOfAdoptionDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ExternalCreditRatingStandardPoorsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "External Credit Rating, Standard &amp; Poor's [Domain]"
       }
      }
     },
     "localname": "ExternalCreditRatingStandardPoorsMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAmortizedCostOfDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ItemsIncludedInConsolidatedStatementOfFinancialConditionAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Items included in Consolidated Balance Sheets"
       }
      }
     },
     "localname": "ItemsIncludedInConsolidatedStatementOfFinancialConditionAbstract",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "srt_MaximumMember": {
     "auth_ref": [
      "r361",
      "r368",
      "r399",
      "r401",
      "r591",
      "r592",
      "r593",
      "r598",
      "r599",
      "r600",
      "r640",
      "r719",
      "r722",
      "r757",
      "r758"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Maximum"
       }
      }
     },
     "localname": "MaximumMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureLeasesDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_MinimumMember": {
     "auth_ref": [
      "r361",
      "r368",
      "r399",
      "r401",
      "r591",
      "r592",
      "r593",
      "r598",
      "r599",
      "r600",
      "r640",
      "r719",
      "r722",
      "r757",
      "r758"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Minimum"
       }
      }
     },
     "localname": "MinimumMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureLeasesDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ProductOrServiceAxis": {
     "auth_ref": [
      "r183",
      "r382",
      "r384",
      "r641",
      "r718",
      "r720"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Products and Services [Axis]"
       }
      }
     },
     "localname": "ProductOrServiceAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomersDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_ProductsAndServicesDomain": {
     "auth_ref": [
      "r183",
      "r382",
      "r384",
      "r641",
      "r718",
      "r720"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Products and Services [Domain]"
       }
      }
     },
     "localname": "ProductsAndServicesDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomersDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RangeAxis": {
     "auth_ref": [
      "r361",
      "r368",
      "r389",
      "r399",
      "r401",
      "r591",
      "r592",
      "r593",
      "r598",
      "r599",
      "r600",
      "r640",
      "r719",
      "r722",
      "r757",
      "r758"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Range [Axis]"
       }
      }
     },
     "localname": "RangeAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureLeasesDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_RangeMember": {
     "auth_ref": [
      "r361",
      "r368",
      "r389",
      "r399",
      "r401",
      "r591",
      "r592",
      "r593",
      "r598",
      "r599",
      "r600",
      "r640",
      "r719",
      "r722",
      "r757",
      "r758"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Range [Domain]"
       }
      }
     },
     "localname": "RangeMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureLeasesDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RegulatoryCapitalRequirementsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "REGULATORY CAPITAL"
       }
      }
     },
     "localname": "RegulatoryCapitalRequirementsAbstract",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "srt_RepurchaseAgreementCounterpartyNameDomain": {
     "auth_ref": [
      "r39",
      "r40",
      "r101",
      "r102",
      "r362",
      "r369"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Counterparty Name [Domain]"
       }
      }
     },
     "localname": "RepurchaseAgreementCounterpartyNameDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RestatementAxis": {
     "auth_ref": [
      "r3",
      "r105",
      "r106",
      "r107",
      "r109",
      "r110",
      "r114",
      "r115",
      "r116",
      "r117",
      "r119",
      "r120",
      "r121",
      "r122",
      "r123",
      "r124",
      "r140",
      "r273",
      "r274",
      "r437",
      "r452",
      "r514",
      "r518",
      "r519",
      "r520",
      "r725",
      "r726",
      "r727",
      "r728",
      "r729",
      "r730",
      "r731",
      "r732",
      "r733",
      "r734",
      "r786",
      "r787"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Revision of Prior Period [Axis]"
       }
      }
     },
     "localname": "RestatementAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesErrorCorrectionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_RestatementDomain": {
     "auth_ref": [
      "r3",
      "r105",
      "r106",
      "r107",
      "r109",
      "r110",
      "r114",
      "r115",
      "r116",
      "r117",
      "r119",
      "r120",
      "r121",
      "r122",
      "r123",
      "r124",
      "r140",
      "r273",
      "r274",
      "r437",
      "r452",
      "r514",
      "r518",
      "r519",
      "r520",
      "r725",
      "r726",
      "r727",
      "r728",
      "r729",
      "r730",
      "r731",
      "r732",
      "r733",
      "r734",
      "r786",
      "r787"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Revision of Prior Period [Domain]"
       }
      }
     },
     "localname": "RestatementDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesErrorCorrectionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RevisionOfPriorPeriodErrorCorrectionAdjustmentMember": {
     "auth_ref": [
      "r114",
      "r115",
      "r116",
      "r119",
      "r120",
      "r122",
      "r123"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Error correction"
       }
      }
     },
     "localname": "RevisionOfPriorPeriodErrorCorrectionAdjustmentMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesErrorCorrectionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ScenarioPreviouslyReportedMember": {
     "auth_ref": [
      "r3",
      "r105",
      "r107",
      "r109",
      "r110",
      "r114",
      "r115",
      "r116",
      "r117",
      "r119",
      "r120",
      "r122",
      "r123",
      "r140",
      "r273",
      "r274",
      "r437",
      "r452",
      "r514",
      "r518",
      "r519",
      "r520",
      "r725",
      "r726",
      "r727",
      "r728",
      "r729",
      "r730",
      "r731",
      "r732",
      "r733",
      "r734",
      "r786",
      "r787"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Previously reported"
       }
      }
     },
     "localname": "ScenarioPreviouslyReportedMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesErrorCorrectionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_SegmentGeographicalDomain": {
     "auth_ref": [
      "r184",
      "r185",
      "r382",
      "r385",
      "r721",
      "r747",
      "r748",
      "r749",
      "r750",
      "r751",
      "r752",
      "r753",
      "r754",
      "r755"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Geographical [Domain]"
       }
      }
     },
     "localname": "SegmentGeographicalDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesDetails",
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_StandardPoorsBBBRatingMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "BBB/BBB-"
       }
      }
     },
     "localname": "StandardPoorsBBBRatingMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAmortizedCostOfDebtDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_StatementGeographicalAxis": {
     "auth_ref": [
      "r184",
      "r185",
      "r382",
      "r385",
      "r721",
      "r745",
      "r747",
      "r748",
      "r749",
      "r750",
      "r751",
      "r752",
      "r753",
      "r754",
      "r755"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Geographical [Axis]"
       }
      }
     },
     "localname": "StatementGeographicalAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesDetails",
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_TitleOfIndividualAxis": {
     "auth_ref": [
      "r189",
      "r579"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Title of Individual [Axis]"
       }
      }
     },
     "localname": "TitleOfIndividualAxis",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_TitleOfIndividualWithRelationshipToEntityDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Relationship to Entity [Domain]"
       }
      }
     },
     "localname": "TitleOfIndividualWithRelationshipToEntityDomain",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_WeightedAverageMember": {
     "auth_ref": [
      "r591",
      "r593",
      "r600",
      "r757",
      "r758"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Weighted Average"
       }
      }
     },
     "localname": "WeightedAverageMember",
     "nsuri": "http://fasb.org/srt/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccountingPoliciesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES"
       }
      }
     },
     "localname": "AccountingPoliciesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccountingStandardsUpdate201613Member": {
     "auth_ref": [
      "r268"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accounting Standards Update 2016-13 Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.",
        "label": "Accounting Standards Update 2016-13",
        "terseLabel": "ASU No 2016-13"
       }
      }
     },
     "localname": "AccountingStandardsUpdate201613Member",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAllowanceForCreditLossesDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccountsNotesAndLoansReceivableLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Accounts, Notes, Loans and Financing Receivable [Line Items]",
        "terseLabel": "Accounts, Notes, Loans and Financing Receivable [Line Items]"
       }
      }
     },
     "localname": "AccountsNotesAndLoansReceivableLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccountsReceivableNoncurrentAccruedInterestAfterAllowanceForCreditLoss": {
     "auth_ref": [
      "r276",
      "r289"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of accrued interest on accounts receivable classified as noncurrent.",
        "label": "Accounts Receivable, Noncurrent, Accrued Interest, after Allowance for Credit Loss",
        "terseLabel": "Accrued interest receivable"
       }
      }
     },
     "localname": "AccountsReceivableNoncurrentAccruedInterestAfterAllowanceForCreditLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccruedLiabilitiesFairValueDisclosure": {
     "auth_ref": [
      "r24"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of accrued expenses.",
        "label": "Accrued Liabilities, Fair Value Disclosure",
        "terseLabel": "Accrued interest payable"
       }
      }
     },
     "localname": "AccruedLiabilitiesFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax": {
     "auth_ref": [
      "r17",
      "r46",
      "r48",
      "r49",
      "r706",
      "r730",
      "r734"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 5.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.",
        "label": "Accumulated Other Comprehensive Income (Loss), Net of Tax",
        "terseLabel": "Accumulated other comprehensive (loss) income, net of tax"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeLossNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeMember": {
     "auth_ref": [
      "r45",
      "r49",
      "r57",
      "r58",
      "r59",
      "r105",
      "r106",
      "r107",
      "r464",
      "r725",
      "r726",
      "r787"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accumulated increase (decrease) in equity from transactions and other events and circumstances from non-owner sources, attributable to the parent. Excludes net income (loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners.",
        "label": "Accumulated Other Comprehensive Income, Net of Tax"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AdditionalPaidInCapitalCommonStock": {
     "auth_ref": [
      "r15"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Value received from shareholders in common stock-related transactions that are in excess of par value or stated value and amounts received from other stock-related transactions. Includes only common stock transactions (excludes preferred stock transactions). May be called contributed capital, capital in excess of par, capital surplus, or paid-in capital.",
        "label": "Additional Paid in Capital, Common Stock",
        "terseLabel": "Additional paid-in capital"
       }
      }
     },
     "localname": "AdditionalPaidInCapitalCommonStock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AdditionalPaidInCapitalMember": {
     "auth_ref": [
      "r105",
      "r106",
      "r107",
      "r434",
      "r435",
      "r436",
      "r518"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders.",
        "label": "Additional Paid-in Capital"
       }
      }
     },
     "localname": "AdditionalPaidInCapitalMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AdjustmentsForNewAccountingPronouncementsAxis": {
     "auth_ref": [
      "r0",
      "r1",
      "r2",
      "r3",
      "r4",
      "r109",
      "r110",
      "r111",
      "r112",
      "r124",
      "r220",
      "r221",
      "r269",
      "r270",
      "r271",
      "r272",
      "r273",
      "r274",
      "r349",
      "r430",
      "r431",
      "r432",
      "r433",
      "r434",
      "r435",
      "r436",
      "r437",
      "r449",
      "r450",
      "r451",
      "r452",
      "r510",
      "r511",
      "r512",
      "r513",
      "r514",
      "r515",
      "r516",
      "r517",
      "r518",
      "r519",
      "r520",
      "r545",
      "r546",
      "r547",
      "r548",
      "r549",
      "r550",
      "r551",
      "r552",
      "r578",
      "r643",
      "r644",
      "r645",
      "r723",
      "r724",
      "r725",
      "r726",
      "r727",
      "r728",
      "r729",
      "r730",
      "r731",
      "r732",
      "r733",
      "r734",
      "r783",
      "r784",
      "r785",
      "r786",
      "r787"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by amendment to accounting standards.",
        "label": "Adjustments for New Accounting Pronouncements [Axis]"
       }
      }
     },
     "localname": "AdjustmentsForNewAccountingPronouncementsAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAllowanceForCreditLossesDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue": {
     "auth_ref": [
      "r403",
      "r405",
      "r440",
      "r441"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase to additional paid-in capital (APIC) for recognition of cost for award under share-based payment arrangement.",
        "label": "Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition",
        "terseLabel": "Share-based compensation"
       }
      }
     },
     "localname": "AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]",
        "terseLabel": "Adjustments to reconcile net income to net cash from operating activities"
       }
      }
     },
     "localname": "AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AgencySecuritiesMember": {
     "auth_ref": [
      "r263"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Securities issued by government sponsored entities.",
        "label": "U.S. agency securities"
       }
      }
     },
     "localname": "AgencySecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AllocatedShareBasedCompensationExpense": {
     "auth_ref": [
      "r405",
      "r427",
      "r439"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.",
        "label": "Allocated Share-based Compensation Expense",
        "terseLabel": "Share-based compensation expense"
       }
      }
     },
     "localname": "AllocatedShareBasedCompensationExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock": {
     "auth_ref": [
      "r199",
      "r283"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of allowance for credit loss on financing receivable.",
        "label": "Allowance for Credit Losses on Financing Receivables [Table Text Block]",
        "terseLabel": "Allowance for Credit Losses on Financing Receivables"
       }
      }
     },
     "localname": "AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_AllowanceForLoanAndLeaseLossesLoansSold": {
     "auth_ref": [
      "r205"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of reduction of allowance reserve for credit loss arising from sale of loan and lease portfolios.",
        "label": "Allowance for Loan and Lease Losses, Loans Sold",
        "terseLabel": "Holdback for loans sold to FHLB"
       }
      }
     },
     "localname": "AllowanceForLoanAndLeaseLossesLoansSold",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AmortizationOfIntangibleAssets": {
     "auth_ref": [
      "r90",
      "r319",
      "r323"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 10.0,
       "parentTag": "us-gaap_NoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.",
        "label": "Amortization of Intangible Assets",
        "negatedLabel": "Amortization",
        "terseLabel": "Amortization of core deposit intangible"
       }
      }
     },
     "localname": "AmortizationOfIntangibleAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount": {
     "auth_ref": [
      "r137"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.",
        "label": "Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount",
        "terseLabel": "Potentially dilutive weighted average share options that were not included in the computation of diluted earnings per share because to do so would be anti-dilutive"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareScheduleOfEarningsPerShareBasicAndDilutedDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_AssetPledgedAsCollateralMember": {
     "auth_ref": [
      "r459",
      "r465",
      "r607"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Asset pledged as collateral.",
        "label": "Asset pledged as collateral"
       }
      }
     },
     "localname": "AssetPledgedAsCollateralMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_Assets": {
     "auth_ref": [
      "r99",
      "r159",
      "r172",
      "r179",
      "r267",
      "r350",
      "r351",
      "r352",
      "r353",
      "r354",
      "r355",
      "r356",
      "r357",
      "r358",
      "r359",
      "r360",
      "r459",
      "r465",
      "r544",
      "r581",
      "r583",
      "r653",
      "r705"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.",
        "label": "Assets",
        "totalLabel": "TOTAL ASSETS"
       }
      }
     },
     "localname": "Assets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Assets [Abstract]",
        "terseLabel": "ASSETS"
       }
      }
     },
     "localname": "AssetsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AssetsAverageOutstanding": {
     "auth_ref": [
      "r765"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Average amount outstanding of interest-earning and noninterest-earning assets.",
        "label": "Assets, Average Outstanding",
        "verboseLabel": "Total average assets for period ended"
       }
      }
     },
     "localname": "AssetsAverageOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetsCurrentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Assets, Current [Abstract]",
        "terseLabel": "Assets"
       }
      }
     },
     "localname": "AssetsCurrentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AssetsFairValueDisclosure": {
     "auth_ref": [
      "r522"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.",
        "label": "Assets, Fair Value Disclosure",
        "terseLabel": "Total assets measured at fair value"
       }
      }
     },
     "localname": "AssetsFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax": {
     "auth_ref": [
      "r230"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax",
        "terseLabel": "Unrealized Gains"
       }
      }
     },
     "localname": "AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax": {
     "auth_ref": [
      "r231"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax",
        "negatedLabel": "Unrealized Losses"
       }
      }
     },
     "localname": "AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis": {
     "auth_ref": [
      "r228",
      "r303"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_DebtSecurities",
       "weight": 1.0
      },
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails1": {
       "order": 2.0,
       "parentTag": "us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturity",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Available-for-sale Debt Securities, Amortized Cost Basis",
        "terseLabel": "Securities available-for-sale, Total",
        "verboseLabel": "Amortized cost"
       }
      }
     },
     "localname": "AvailableForSaleDebtSecuritiesAmortizedCostBasis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "SECURITIES AVAILABLE-FOR-SALE",
        "terseLabel": "Activity in securities available-for-sale:"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]",
        "terseLabel": "Unrealized Losses"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]",
        "terseLabel": "Fair Value"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost": {
     "auth_ref": [
      "r236"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis",
        "terseLabel": "Securities available-for-sale, Due after five years through ten years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue": {
     "auth_ref": [
      "r232",
      "r236",
      "r687"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value",
        "terseLabel": "Securities available-for-sale, Due after five years through ten years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost": {
     "auth_ref": [
      "r235"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis",
        "terseLabel": "Securities available-for-sale, Due after one year through five years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue": {
     "auth_ref": [
      "r232",
      "r235",
      "r686"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value",
        "terseLabel": "Securities available-for-sale, Due after one year through five years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost": {
     "auth_ref": [
      "r237"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing after tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis",
        "terseLabel": "Securities available-for-sale, Due after ten years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue": {
     "auth_ref": [
      "r232",
      "r237",
      "r688"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing after tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value",
        "terseLabel": "Securities available-for-sale, Due after ten years"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]",
        "terseLabel": "Amortized Cost"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesAmortizedCostAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]",
        "terseLabel": "Fair Value"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate": {
     "auth_ref": [
      "r232",
      "r238",
      "r689"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date.",
        "label": "Available-for-sale Securities, Debt Maturities, Single Maturity Date",
        "totalLabel": "Securities available-for-sale, Subtotal"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis": {
     "auth_ref": [
      "r232",
      "r238",
      "r684"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date.",
        "label": "Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis",
        "totalLabel": "Securities available-for-sale, Subtotal"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost": {
     "auth_ref": [
      "r234"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis",
        "terseLabel": "Securities available-for-sale, Due in one year or less"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue": {
     "auth_ref": [
      "r232",
      "r234",
      "r685"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value",
        "terseLabel": "Securities available-for-sale, Due in one year or less"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost": {
     "auth_ref": [
      "r238"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), without single maturity date and not allocated over maturity grouping.",
        "label": "Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis",
        "terseLabel": "Securities available-for-sale, Mortgage-backed securities"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue": {
     "auth_ref": [
      "r238",
      "r689"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), without single maturity date and not allocated over maturity grouping.",
        "label": "Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value",
        "terseLabel": "Securities available-for-sale, Mortgage-backed securities"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtSecurities": {
     "auth_ref": [
      "r224",
      "r229",
      "r303",
      "r655"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityFairValue",
       "weight": 1.0
      },
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails1": {
       "order": 2.0,
       "parentTag": "us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityFairValue",
       "weight": 1.0
      },
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Available-for-sale Securities, Debt Securities",
        "terseLabel": "Securities available-for-sale, at fair value",
        "verboseLabel": "Securities available-for-sale, Total"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtSecurities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainLossAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Available-for-sale Securities, Gross Unrealized Gain (Loss) [Abstract]",
        "terseLabel": "Securities available-for-sale:"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesGrossUnrealizedGainLossAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableforsaleSecuritiesMember": {
     "auth_ref": [
      "r260"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Securities available-for-sale."
       }
      }
     },
     "localname": "AvailableforsaleSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueLevel3OnRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AwardTypeAxis": {
     "auth_ref": [
      "r406",
      "r429"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of award under share-based payment arrangement.",
        "label": "Award Type [Axis]"
       }
      }
     },
     "localname": "AwardTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_BankOwnedLifeInsurance": {
     "auth_ref": [
      "r652"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 13.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The carrying amount of a life insurance policy on an officer, executive or employee for which the reporting entity (a bank) is entitled to proceeds from the policy upon death of the insured or surrender of the insurance policy.",
        "label": "Bank Owned Life Insurance",
        "terseLabel": "Bank owned life insurance (\"BOLI\"), net"
       }
      }
     },
     "localname": "BankOwnedLifeInsurance",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BankOwnedLifeInsuranceIncome": {
     "auth_ref": [
      "r675"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      },
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Earnings on or other increases in the value of the cash surrender value of bank owned life insurance policies.",
        "label": "Bank Owned Life Insurance Income",
        "negatedTerseLabel": "Change in cash surrender value of BOLI",
        "terseLabel": "Earnings on cash surrender value of BOLI"
       }
      }
     },
     "localname": "BankOwnedLifeInsuranceIncome",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BankingAndThriftOtherDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "OTHER REAL ESTATE OWNED (\"OREO\")"
       }
      }
     },
     "localname": "BankingAndThriftOtherDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_BasisOfAccountingPolicyPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy for basis of accounting, or basis of presentation, used to prepare the financial statements (for example, US Generally Accepted Accounting Principles, Other Comprehensive Basis of Accounting, IFRS).",
        "label": "Basis of Accounting, Policy [Policy Text Block]",
        "terseLabel": "Financial Statement Presentation"
       }
      }
     },
     "localname": "BasisOfAccountingPolicyPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock": {
     "auth_ref": [
      "r104"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for the basis of presentation and significant accounting policies concepts. Basis of presentation describes the underlying basis used to prepare the financial statements (for example, US Generally Accepted Accounting Principles, Other Comprehensive Basis of Accounting, IFRS).  Accounting policies describe all significant accounting policies of the reporting entity.",
        "label": "Basis of Presentation and Significant Accounting Policies [Text Block]",
        "terseLabel": "BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES"
       }
      }
     },
     "localname": "BasisOfPresentationAndSignificantAccountingPoliciesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_BusinessAcquisitionAcquireeDomain": {
     "auth_ref": [
      "r398",
      "r400"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Identification of the acquiree in a material business combination (or series of individually immaterial business combinations), which may include the name or other type of identification of the acquiree.",
        "label": "Business Acquisition, Acquiree [Domain]"
       }
      }
     },
     "localname": "BusinessAcquisitionAcquireeDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_BusinessAcquisitionAxis": {
     "auth_ref": [
      "r398",
      "r400",
      "r455",
      "r456"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by business combination or series of individually immaterial business combinations.",
        "label": "Business Acquisition [Axis]"
       }
      }
     },
     "localname": "BusinessAcquisitionAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CarryingReportedAmountFairValueDisclosureMember": {
     "auth_ref": [
      "r542",
      "r543"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Measured as reported on the statement of financial position (balance sheet).",
        "label": "Carrying Amount"
       }
      }
     },
     "localname": "CarryingReportedAmountFairValueDisclosureMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CashAndCashEquivalentsAtCarryingValue": {
     "auth_ref": [
      "r7",
      "r21",
      "r92"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.",
        "label": "Cash and Cash Equivalents, at Carrying Value",
        "totalLabel": "Total cash and cash equivalents"
       }
      }
     },
     "localname": "CashAndCashEquivalentsAtCarryingValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashAndDueFromBanks": {
     "auth_ref": [
      "r650"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_CashAndCashEquivalentsAtCarryingValue",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "For banks and other depository institutions: Includes cash on hand (currency and coin), cash items in process of collection, noninterest bearing deposits due from other financial institutions (including corporate credit unions), and noninterest bearing balances with the Federal Reserve Banks, Federal Home Loan Banks and central banks.",
        "label": "Cash and Due from Banks",
        "terseLabel": "Cash and due from banks"
       }
      }
     },
     "localname": "CashAndDueFromBanks",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents": {
     "auth_ref": [
      "r84",
      "r92",
      "r97"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage. Excludes amount for disposal group and discontinued operations. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.",
        "label": "Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents",
        "periodEndLabel": "CASH AND CASH EQUIVALENTS, end of period",
        "periodStartLabel": "CASH AND CASH EQUIVALENTS, beginning of period"
       }
      }
     },
     "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect": {
     "auth_ref": [
      "r84",
      "r553"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage; excluding effect from exchange rate change. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.",
        "label": "Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect",
        "totalLabel": "NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS"
       }
      }
     },
     "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashFlowHedgingMember": {
     "auth_ref": [
      "r476"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Hedge of the exposure to variability in the cash flows of a recognized asset or liability, or of a forecasted transaction, that is attributable to a particular risk.",
        "label": "Cash Flow Hedges"
       }
      }
     },
     "localname": "CashFlowHedgingMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CertificatesOfDepositAtCarryingValue": {
     "auth_ref": [
      "r21"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A savings certificate entitling the Entity (that is, bearer) to receive interest at an established maturity date, based upon a fixed interest rate.  A certificate of deposit may be issued in any denomination. Certificates of deposit are generally issued by commercial banks and, therefore, insured by the FDIC (up to the prescribed limit).  Certificates of deposit generally restrict holders from withdrawing funds on demand without the incurrence of penalties.  Generally, only certificates of deposit with original maturities of three months or less qualify as cash equivalents. Original maturity means original maturity to the entity holding the investment. As a related example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.",
        "label": "Certificates of Deposit, at Carrying Value",
        "terseLabel": "Certificates of deposit at other financial institutions"
       }
      }
     },
     "localname": "CertificatesOfDepositAtCarryingValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1": {
     "auth_ref": [
      "r506"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.",
        "label": "Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments",
        "terseLabel": "Net gains (losses) on fair value hedging relationships - Recognized on derivatives designated as hedging instruments"
       }
      }
     },
     "localname": "ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1": {
     "auth_ref": [
      "r506"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.",
        "label": "Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge",
        "terseLabel": "Net gains (losses) on fair value hedging relationships - Recognized on hedged items"
       }
      }
     },
     "localname": "ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CollateralAlreadyPostedAggregateFairValue": {
     "auth_ref": [
      "r496"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.",
        "label": "Collateral Already Posted, Aggregate Fair Value",
        "terseLabel": "Fair value of collateral already posted"
       }
      }
     },
     "localname": "CollateralAlreadyPostedAggregateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesCreditRiskRelatedContingentFeaturesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CollateralAxis": {
     "auth_ref": [
      "r297"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by category of collateral or no collateral, from lender's perspective.",
        "label": "Collateral Held [Axis]"
       }
      }
     },
     "localname": "CollateralAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CollateralDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Category of collateral or no collateral, from lender's perspective.",
        "label": "Collateral Held [Domain]"
       }
      }
     },
     "localname": "CollateralDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommercialLoanMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A loan, whether secured or unsecured, to a company for purposes such as seasonal working capital needs, inventory financing, equipment purchases and acquisitions.",
        "label": "COMMERCIAL BUSINESS LOANS."
       }
      }
     },
     "localname": "CommercialLoanMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommercialPortfolioSegmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Portfolio segment of the company's total financing receivables related to commercial receivables.",
        "label": "COMMERCIAL BUSINESS LOANS"
       }
      }
     },
     "localname": "CommercialPortfolioSegmentMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommercialRealEstateMember": {
     "auth_ref": [
      "r298",
      "r390"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Property that is solely used for business purposes.",
        "label": "Commercial"
       }
      }
     },
     "localname": "CommercialRealEstateMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommitmentsAndContingencies": {
     "auth_ref": [
      "r25",
      "r335",
      "r661",
      "r710"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the caption on the face of the balance sheet to indicate that the entity has entered into (1) purchase or supply arrangements that will require expending a portion of its resources to meet the terms thereof, and (2) is exposed to potential losses or, less frequently, gains, arising from (a) possible claims against a company's resources due to future performance under contract terms, and (b) possible losses or likely gains from uncertainties that will ultimately be resolved when one or more future events that are deemed likely to occur do occur or fail to occur.",
        "label": "Commitments and Contingencies",
        "terseLabel": "COMMITMENTS AND CONTINGENCIES (NOTE 9)"
       }
      }
     },
     "localname": "CommitmentsAndContingencies",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CommitmentsAndContingenciesDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Commitments and Contingencies."
       }
      }
     },
     "localname": "CommitmentsAndContingenciesDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_CommitmentsAndContingenciesDisclosureTextBlock": {
     "auth_ref": [
      "r332",
      "r333",
      "r334",
      "r343",
      "r746"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for commitments and contingencies.",
        "label": "Commitments and Contingencies Disclosure [Text Block]",
        "terseLabel": "Commitments and Contingencies"
       }
      }
     },
     "localname": "CommitmentsAndContingenciesDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingencies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_CommitmentsFairValueDisclosure": {
     "auth_ref": [
      "r11"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of arrangements with third parties, including, but not limited to, operating lease arrangement and arrangement in which the entity has agreed to expend funds to procure goods or services, or has agreed to commit resources to supply goods or services.",
        "label": "Commitments, Fair Value Disclosure",
        "terseLabel": "Fair value interest rate locks with customers"
       }
      }
     },
     "localname": "CommitmentsFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CommitmentsToExtendCreditMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loan commitments are legally binding commitments to extend credit to a counterparty under certain terms and conditions.",
        "label": "Commitments to Extend Credit"
       }
      }
     },
     "localname": "CommitmentsToExtendCreditMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommonStockDividendsPerShareCashPaid": {
     "auth_ref": [
      "r372"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate dividends paid during the period for each share of common stock outstanding.",
        "label": "Common Stock, Dividends, Per Share, Cash Paid",
        "terseLabel": "Dividends paid (in dollars per share)"
       }
      }
     },
     "localname": "CommonStockDividendsPerShareCashPaid",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquityParenthetical"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_CommonStockMember": {
     "auth_ref": [
      "r105",
      "r106",
      "r518"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Stock that is subordinate to all other stock of the issuer.",
        "label": "Common Stock"
       }
      }
     },
     "localname": "CommonStockMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommonStockParOrStatedValuePerShare": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Face amount or stated value per share of common stock.",
        "label": "Common Stock, Par or Stated Value Per Share",
        "terseLabel": "Common stock par value, in dollars per share"
       }
      }
     },
     "localname": "CommonStockParOrStatedValuePerShare",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_CommonStockSharesAuthorized": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The maximum number of common shares permitted to be issued by an entity's charter and bylaws.",
        "label": "Common Stock, Shares Authorized",
        "terseLabel": "Common stock, shares authorized"
       }
      }
     },
     "localname": "CommonStockSharesAuthorized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockSharesIssued": {
     "auth_ref": [
      "r13"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.",
        "label": "Common Stock, Shares, Issued",
        "terseLabel": "Common stock, shares issued"
       }
      }
     },
     "localname": "CommonStockSharesIssued",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockSharesOutstanding": {
     "auth_ref": [
      "r13",
      "r371"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.",
        "label": "Common Stock, Shares, Outstanding",
        "terseLabel": "Common stock, shares outstanding"
       }
      }
     },
     "localname": "CommonStockSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockValue": {
     "auth_ref": [
      "r13",
      "r583"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity.",
        "label": "Common Stock, Value, Issued",
        "terseLabel": "Common stock, $.01 par value; 45,000,000 shares authorized;7,726,232 and 8,169,887 shares issued and outstanding at June 30, 2022 and December 31, 2021, respectively"
       }
      }
     },
     "localname": "CommonStockValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CompensationAndEmployeeBenefitPlansTextBlock": {
     "auth_ref": [
      "r387",
      "r388",
      "r402",
      "r445"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for an entity's employee compensation and benefit plans, including, but not limited to, postemployment and postretirement benefit plans, defined benefit pension plans, defined contribution plans, non-qualified and supplemental benefit plans, deferred compensation, share-based compensation, life insurance, severance, health care, unemployment and other benefit plans.",
        "label": "Compensation and Employee Benefit Plans [Text Block]",
        "terseLabel": "EMPLOYEE BENEFITS"
       }
      }
     },
     "localname": "CompensationAndEmployeeBenefitPlansTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEmployeeBenefits"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_CompensationAndRetirementDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "EMPLOYEE BENEFITS"
       }
      }
     },
     "localname": "CompensationAndRetirementDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]",
        "terseLabel": "Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]"
       }
      }
     },
     "localname": "ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRegulatoryCapitalRegulatoryCapitalRatiosPolicyDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ComprehensiveIncomeNetOfTax": {
     "auth_ref": [
      "r53",
      "r55",
      "r56",
      "r65",
      "r667",
      "r713"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.",
        "label": "Comprehensive Income (Loss), Net of Tax, Attributable to Parent",
        "totalLabel": "COMPREHENSIVE (LOSS) INCOME"
       }
      }
     },
     "localname": "ComprehensiveIncomeNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ConsolidationPolicyTextBlock": {
     "auth_ref": [
      "r98",
      "r461"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy regarding (1) the principles it follows in consolidating or combining the separate financial statements, including the principles followed in determining the inclusion or exclusion of subsidiaries or other entities in the consolidated or combined financial statements and (2) its treatment of interests (for example, common stock, a partnership interest or other means of exerting influence) in other entities, for example consolidation or use of the equity or cost methods of accounting.  The accounting policy may also address the accounting treatment for intercompany accounts and transactions, noncontrolling interest, and the income statement treatment in consolidation for issuances of stock by a subsidiary.",
        "label": "Consolidation, Policy [Policy Text Block]",
        "terseLabel": "Principles of Consolidation"
       }
      }
     },
     "localname": "ConsolidationPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ConstructionLoansMember": {
     "auth_ref": [
      "r745"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A borrowing arrangement which provides the entity constructing a facility (such as a building and a landfill) with funds to effect construction, generally on a draw down, or as needed, basis.",
        "label": "Construction and development"
       }
      }
     },
     "localname": "ConstructionLoansMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ConsumerLoanMember": {
     "auth_ref": [
      "r301"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loan or extension of credit for personal, family, or household use excluding real estate.",
        "label": "CONSUMER LOANS."
       }
      }
     },
     "localname": "ConsumerLoanMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ConsumerPortfolioSegmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Portfolio segment of the company's total financing receivables related to consumer receivables.",
        "label": "CONSUMER LOANS"
       }
      }
     },
     "localname": "ConsumerPortfolioSegmentMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets": {
     "auth_ref": [
      "r616"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of contractually specified servicing fee, late fee, and ancillary fee recognized as income for servicing asset and servicing liability.",
        "label": "Contractually Specified Servicing Fees, Late Fees, and Ancillary Fees Earned in Exchange for Servicing Financial Assets",
        "terseLabel": "Contractually specified servicing fees, late fees, and other ancillary fees"
       }
      }
     },
     "localname": "ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CorporateDebtSecuritiesMember": {
     "auth_ref": [
      "r390",
      "r397",
      "r735"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Debt securities issued by domestic or foreign corporate business, banks and other entities with a promise of repayment.",
        "label": "Corporate securities"
       }
      }
     },
     "localname": "CorporateDebtSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAllowanceForCreditLossesDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAmortizedCostOfDebtDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DebtInstrumentFairValue": {
     "auth_ref": [
      "r363",
      "r365",
      "r366",
      "r541"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.",
        "label": "Debt Instrument, Fair Value Disclosure",
        "terseLabel": "Borrowings"
       }
      }
     },
     "localname": "DebtInstrumentFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecurities": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), investment in debt security measured at amortized cost (held-to-maturity), and investment in debt security measured at fair value with change in fair value recognized in net income (trading).",
        "label": "Debt Securities",
        "totalLabel": "Total securities"
       }
      }
     },
     "localname": "DebtSecurities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss": {
     "auth_ref": [
      "r233",
      "r303",
      "r304",
      "r305"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of accrued interest on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss",
        "verboseLabel": "Accrued interest receivable on available-for-sale debt securities"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturity": {
     "auth_ref": [
      "r655"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails1": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) and investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities, Available-for-sale and Held-to-maturity",
        "totalLabel": "Amortized cost"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleAndHeldToMaturity",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Debt Securities, Available-for-sale and Held-to-maturity [Abstract]",
        "terseLabel": "Total securities"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleAndHeldToMaturityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityCumulativeUnrecognizedGain": {
     "auth_ref": [
      "r230",
      "r249"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cumulative unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity) and investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities, Held to Maturity and Available for Sale, Accumulated Unrecognized Gain",
        "terseLabel": "Unrealized gains"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleAndHeldToMaturityCumulativeUnrecognizedGain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityCumulativeUnrecognizedLoss": {
     "auth_ref": [
      "r231",
      "r250"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cumulative unrecognized loss on investment in debt security measured at amortized cost (held-to-maturity) and investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities, Held to Maturity and Available for Sale, Accumulated Unrecognized Loss",
        "negatedLabel": "Unrealized losses"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleAndHeldToMaturityCumulativeUnrecognizedLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityFairValue": {
     "auth_ref": [
      "r229",
      "r248"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails1": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (held-to-maturity) and investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities, Available-for-sale and Held-to-maturity, Fair Value",
        "terseLabel": "Total securities, at fair value",
        "totalLabel": "Total securities"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleAndHeldToMaturityFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger": {
     "auth_ref": [
      "r258",
      "r309",
      "r312"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.",
        "label": "Debt Securities Available For Sale Continuous Unrealized Loss Position 12 Months Or Longer",
        "terseLabel": "Securities available-for-sale, Unrealized loss position, Fair Value, 12 Months or Longer"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss": {
     "auth_ref": [
      "r258",
      "r309"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.",
        "label": "Debt Securities Available For Sale Continuous Unrealized Loss Position 12 Months Or Longer Accumulated Loss",
        "negatedLabel": "Securities available-for-sale, Unrealized loss position, Unrealized losses, 12 Months or Longer"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months": {
     "auth_ref": [
      "r258",
      "r309",
      "r312"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.",
        "label": "Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months",
        "terseLabel": "Securities available-for-sale, Unrealized loss position, Fair Value, Less than 12 Months"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss": {
     "auth_ref": [
      "r258",
      "r309"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.",
        "label": "Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss",
        "negatedLabel": "Securities available-for-sale, Unrealized loss position, Unrealized losses, Less than 12 Months"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleExcludedAccruedInterestFromAmortizedCost": {
     "auth_ref": [
      "r233",
      "r305"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicates (true false) whether practical expedient was elected to exclude accrued interest from amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities, Available-for-Sale, Excluded Accrued Interest from Amortized Cost [true false]",
        "terseLabel": "Accrued interest from amortized cost"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleExcludedAccruedInterestFromAmortizedCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails"
     ],
     "xbrltype": "booleanItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleMeasurementInput": {
     "auth_ref": [
      "r527"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Value of input used to measure investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities, Available-for-sale, Measurement Input",
        "terseLabel": "Measurement inputs (as a percent)"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleMeasurementInput",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails"
     ],
     "xbrltype": "decimalItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleMeasurementInputExtensibleList": {
     "auth_ref": [
      "r526"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicates measurement input for investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities, Available-for-sale, Measurement Input [Extensible List]"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleMeasurementInputExtensibleList",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails"
     ],
     "xbrltype": "enumerationSetItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleRealizedGain": {
     "auth_ref": [
      "r261"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities Available For Sale Realized Gain",
        "terseLabel": "Gains from securities available-for-sale"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleRealizedGain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleRealizedLoss": {
     "auth_ref": [
      "r261"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities Available For Sale Realized Loss",
        "terseLabel": "Losses from securities available-for-sale"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleRealizedLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleTable": {
     "auth_ref": [
      "r263"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities, Available-for-sale [Table]"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition": {
     "auth_ref": [
      "r255",
      "r306",
      "r312"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position without allowance for credit loss.",
        "label": "Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss",
        "totalLabel": "Securities available-for-sale, Unrealized loss position, Fair Value"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleUnrealizedLossPosition",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss": {
     "auth_ref": [
      "r256",
      "r307"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.",
        "label": "Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss",
        "negatedTotalLabel": "Securities available-for-sale, Unrealized losses"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleValuationTechniqueExtensibleList": {
     "auth_ref": [
      "r526"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicates valuation technique for measuring investment in debt security at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities, Available-for-sale, Valuation Technique [Extensible List]"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleValuationTechniqueExtensibleList",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails"
     ],
     "xbrltype": "enumerationSetItemType"
    },
    "us-gaap_DebtSecuritiesHeldToMaturityAccruedInterestBeforeAllowanceForCreditLoss": {
     "auth_ref": [
      "r290"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before allowance for credit loss, of accrued interest on investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Held-to-Maturity, Accrued Interest, before Allowance for Credit Loss",
        "verboseLabel": "Accrued interest receivable on held to maturity debt securities"
       }
      }
     },
     "localname": "DebtSecuritiesHeldToMaturityAccruedInterestBeforeAllowanceForCreditLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLoss": {
     "auth_ref": [
      "r241",
      "r275",
      "r278",
      "r282"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of allowance for credit loss for debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Held-to-maturity, Allowance for Credit Loss",
        "periodEndLabel": "Total ending allowance balance",
        "periodStartLabel": "Beginning allowance balance",
        "terseLabel": "Allowance for credit losses",
        "verboseLabel": "Balances of corporate securities"
       }
      }
     },
     "localname": "DebtSecuritiesHeldToMaturityAllowanceForCreditLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAllowanceForCreditLossesDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAmortizedCostOfDebtDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLossCurrent": {
     "auth_ref": [
      "r275"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of allowance for credit loss for debt security measured at amortized cost (held-to-maturity), classified as current.",
        "label": "Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Excluding Accrued Interest, Current",
        "terseLabel": "Allowance for credit losses on debt securities held-to-maturity"
       }
      }
     },
     "localname": "DebtSecuritiesHeldToMaturityAllowanceForCreditLossCurrent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLossRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Debt Securities, Held-to-maturity, Allowance for Credit Loss [Roll Forward]"
       }
      }
     },
     "localname": "DebtSecuritiesHeldToMaturityAllowanceForCreditLossRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAllowanceForCreditLossesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLossTable": {
     "auth_ref": [
      "r283"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about allowance for credit loss on investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Held-to-maturity, Allowance for Credit Loss [Table]"
       }
      }
     },
     "localname": "DebtSecuritiesHeldToMaturityAllowanceForCreditLossTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAllowanceForCreditLossesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLossTableTextBlock": {
     "auth_ref": [
      "r283"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of allowance for credit loss on investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Held-to-maturity, Allowance for Credit Loss [Table Text Block]",
        "terseLabel": "Schedule of allowance of credit losses"
       }
      }
     },
     "localname": "DebtSecuritiesHeldToMaturityAllowanceForCreditLossTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss": {
     "auth_ref": [
      "r224",
      "r244",
      "r245",
      "r655"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Available for Sale, and available for sale and held to Maturity, Amortized Cost",
        "terseLabel": "Securities held-to-maturity, net of allowance for credit losses of $31 and none, respectively (fair value of $8,342 and $8,128, respectively)"
       }
      }
     },
     "localname": "DebtSecuritiesHeldToMaturityAmortizedCostAfterAllowanceForCreditLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesHeldToMaturityCreditLossExpenseReversal": {
     "auth_ref": [
      "r279"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of expense (reversal of expense) for expected credit loss on investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Held-to-maturity, Credit Loss Expense (Reversal)",
        "terseLabel": "Recapture of provision for credit losses"
       }
      }
     },
     "localname": "DebtSecuritiesHeldToMaturityCreditLossExpenseReversal",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAllowanceForCreditLossesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesHeldToMaturityCreditQualityIndicatorTableTextBlock": {
     "auth_ref": [
      "r292"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of credit quality indicator for investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Held-to-maturity, Credit Quality Indicator [Table Text Block]",
        "terseLabel": "Schedule of Amortized cost of debt securities"
       }
      }
     },
     "localname": "DebtSecuritiesHeldToMaturityCreditQualityIndicatorTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DebtSecuritiesHeldToMaturityExcludedAccruedInterest": {
     "auth_ref": [
      "r254",
      "r290"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicates (true false) whether practical expedient was elected to exclude accrued interest from investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Held-to-Maturity, Excluded Accrued Interest [true false]",
        "terseLabel": "Excluded accrued interest"
       }
      }
     },
     "localname": "DebtSecuritiesHeldToMaturityExcludedAccruedInterest",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails"
     ],
     "xbrltype": "booleanItemType"
    },
    "us-gaap_DebtSecuritiesHeldToMaturityNonaccrual": {
     "auth_ref": [
      "r285"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of investment in debt security measured at amortized cost (held-to-maturity) on nonaccrual status.",
        "label": "Debt Securities, Held-to-maturity, Nonaccrual",
        "verboseLabel": "Debt securities classified as nonaccrual or 90 days or more past due and still accruing"
       }
      }
     },
     "localname": "DebtSecuritiesHeldToMaturityNonaccrual",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesHeldtomaturityAllowanceForCreditLossLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]"
       }
      }
     },
     "localname": "DebtSecuritiesHeldtomaturityAllowanceForCreditLossLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAllowanceForCreditLossesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtSecuritiesUnrealizedGainLoss": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), investment in debt security measured at amortized cost (held-to-maturity) and investment in debt security measured at fair value with change in fair value recognized in net income (trading).",
        "label": "Debt Securities, Unrealized Gain (Loss)",
        "terseLabel": "Change in unrealized loss on available - for sale investment securities"
       }
      }
     },
     "localname": "DebtSecuritiesUnrealizedGainLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredIncomeTaxAssetsNet": {
     "auth_ref": [
      "r446",
      "r447"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 6.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, with jurisdictional netting.",
        "label": "Deferred Tax Assets, Net",
        "verboseLabel": "Deferred tax asset, net"
       }
      }
     },
     "localname": "DeferredIncomeTaxAssetsNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredIncomeTaxLiabilitiesNet": {
     "auth_ref": [
      "r446",
      "r447"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 5.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences with jurisdictional netting.",
        "label": "Deferred Income Tax Liabilities, Net",
        "terseLabel": "Deferred tax liability, net"
       }
      }
     },
     "localname": "DeferredIncomeTaxLiabilitiesNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DepositLiabilitiesDisclosuresTextBlock": {
     "auth_ref": [
      "r658",
      "r693",
      "r780",
      "r781"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for deposit liabilities including data and tables. It may include a description of the entity's deposit liabilities, the aggregate amount of time deposits (including certificates of deposit) in denominations of $100,000 or more at the balance sheet date; the aggregate amount of any demand deposits that have been reclassified as loan balances, such as overdrafts, at the balance sheet date; deposits that are received on terms other than those in the normal course of business, the amount of accrued interest on deposit liabilities; securities, mortgage loans or other financial instruments that serve as collateral for deposits; for time deposits having a remaining term of more than one year, the aggregate amount of maturities for each of the five years following the balance sheet date; and the weighted average interest rate for all deposit liabilities held by the entity.",
        "label": "Deposit Liabilities Disclosures [Text Block]",
        "terseLabel": "DEPOSITS"
       }
      }
     },
     "localname": "DepositLiabilitiesDisclosuresTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDeposits"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_Deposits": {
     "auth_ref": [
      "r658"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.",
        "label": "Deposits",
        "totalLabel": "Total deposits"
       }
      }
     },
     "localname": "Deposits",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DepositsByTypeAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "DEPOSITS"
       }
      }
     },
     "localname": "DepositsByTypeAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_DepositsFairValueDisclosure": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.",
        "label": "Deposits, Fair Value Disclosure",
        "terseLabel": "Deposits"
       }
      }
     },
     "localname": "DepositsFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DepositsMoneyMarketDeposits": {
     "auth_ref": [
      "r658"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_Deposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of deposits in accounts that offer many of the same services as checking accounts although transactions may be somewhat more limited, share some of the characteristics of a money market fund and are insured by the Federal government, also known as money market accounts.",
        "label": "Deposits, Money Market Deposits",
        "terseLabel": "Money market"
       }
      }
     },
     "localname": "DepositsMoneyMarketDeposits",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DepositsSavingsDeposits": {
     "auth_ref": [
      "r658"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_Deposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest bearing deposits with no stated maturity, which may include passbook and statement savings accounts and money-market deposit accounts (MMDAs).",
        "label": "Deposits, Savings Deposits",
        "terseLabel": "Savings"
       }
      }
     },
     "localname": "DepositsSavingsDeposits",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DepreciationAmortizationAndAccretionNet": {
     "auth_ref": [
      "r90"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate net amount of depreciation, amortization, and accretion recognized during an accounting period. As a noncash item, the net amount is added back to net income when calculating cash provided by or used in operations using the indirect method.",
        "label": "Depreciation, Amortization and Accretion, Net",
        "terseLabel": "Depreciation, amortization and accretion"
       }
      }
     },
     "localname": "DepreciationAmortizationAndAccretionNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeAmountOfHedgedItem": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of hedged item in hedging relationship. Excludes hedged asset or liability.",
        "label": "Derivative, Amount of Hedged Item",
        "terseLabel": "Amount of designated hedged item"
       }
      }
     },
     "localname": "DerivativeAmountOfHedgedItem",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesCumulativeBasisAdjustmentForFairValueHedgesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeAssetFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection": {
     "auth_ref": [
      "r32",
      "r36"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value, after effects of master netting arrangements, deduction of assets not subject to a master netting arrangement and elected not to be offset, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, offset against an obligation to return collateral.",
        "label": "Derivative Asset, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election",
        "terseLabel": "Gross Amounts Not Offset in the Statement of Financial Position - Net Amount"
       }
      }
     },
     "localname": "DerivativeAssetFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeAssets": {
     "auth_ref": [
      "r30",
      "r35",
      "r40",
      "r541"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeAssetsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.",
        "label": "Derivative Asset",
        "terseLabel": "Interest rate swaps",
        "totalLabel": "Net Amounts of Assets Presented in the Statement of Financial Position"
       }
      }
     },
     "localname": "DerivativeAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeAssetsDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeCollateralRightToReclaimCash": {
     "auth_ref": [
      "r31",
      "r36",
      "r38",
      "r499"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities.",
        "label": "Derivative, Collateral, Right to Reclaim Cash",
        "terseLabel": "Gross Amounts Not Offset in the Statement of Financial Position - Cash Collateral Posted"
       }
      }
     },
     "localname": "DerivativeCollateralRightToReclaimCash",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeContractTypeDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financial instrument or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.",
        "label": "Derivative, Name [Domain]"
       }
      }
     },
     "localname": "DerivativeContractTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeAssetsDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeLiabilitiesDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueLevel3OnRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DerivativeCreditRiskRelatedContingentFeaturesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Derivative, Credit Risk Related Contingent Features [Abstract]",
        "terseLabel": "Credit-risk-related Contingent Features"
       }
      }
     },
     "localname": "DerivativeCreditRiskRelatedContingentFeaturesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesCreditRiskRelatedContingentFeaturesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DerivativeFairValueHedgeIncludedInEffectivenessGainLoss": {
     "auth_ref": [
      "r504"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of gain (loss) on derivative instrument designated and qualifying as fair value hedge included in assessment of hedge effectiveness, recognized in earnings.",
        "label": "Derivative, Fair Value Hedge, Included in Effectiveness, Gain (Loss)",
        "terseLabel": "Net income (expense) recognized on fair value hedges"
       }
      }
     },
     "localname": "DerivativeFairValueHedgeIncludedInEffectivenessGainLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeFairValueOfDerivativeAsset": {
     "auth_ref": [
      "r29",
      "r40",
      "r41",
      "r482",
      "r603"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeAssetsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_DerivativeAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.",
        "label": "Derivative Asset, Fair Value, Gross Asset",
        "terseLabel": "Gross Amounts of Recognized Assets"
       }
      }
     },
     "localname": "DerivativeFairValueOfDerivativeAsset",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeFairValueOfDerivativeLiability": {
     "auth_ref": [
      "r29",
      "r40",
      "r41",
      "r482",
      "r603"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeLiabilitiesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_DerivativeLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.",
        "label": "Derivative Liability, Fair Value, Gross Liability",
        "terseLabel": "Gross Amounts of Recognized Liabilities"
       }
      }
     },
     "localname": "DerivativeFairValueOfDerivativeLiability",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeGainLossOnDerivativeNet": {
     "auth_ref": [
      "r480"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.",
        "label": "Derivative, Gain (Loss) on Derivative, Net",
        "terseLabel": "Total amounts presented in the Consolidated Statements of Income",
        "verboseLabel": "Derivative instruments, (loss) gain on sale of loans"
       }
      }
     },
     "localname": "DerivativeGainLossOnDerivativeNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeInstrumentRiskAxis": {
     "auth_ref": [
      "r40",
      "r479",
      "r483",
      "r489",
      "r493"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of derivative contract.",
        "label": "Derivative Instrument [Axis]"
       }
      }
     },
     "localname": "DerivativeInstrumentRiskAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeAssetsDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeLiabilitiesDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueLevel3OnRecurringBasisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "DERIVATIVES"
       }
      }
     },
     "localname": "DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock": {
     "auth_ref": [
      "r509",
      "r521"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for derivative instruments and hedging activities including, but not limited to, risk management strategies, non-hedging derivative instruments, assets, liabilities, revenue and expenses, and methodologies and assumptions used in determining the amounts.",
        "label": "Derivative Instruments and Hedging Activities Disclosure [Text Block]",
        "terseLabel": "DERIVATIVES"
       }
      }
     },
     "localname": "DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivatives"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis": {
     "auth_ref": [
      "r477",
      "r479",
      "r489"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of hedging relationship.",
        "label": "Hedging Relationship [Axis]"
       }
      }
     },
     "localname": "DerivativeInstrumentsGainLossByHedgingRelationshipAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesCumulativeBasisAdjustmentForFairValueHedgesDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable": {
     "auth_ref": [
      "r477",
      "r479",
      "r489",
      "r493",
      "r494",
      "r501",
      "r507"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about the location and amount of derivative instruments and nonderivative instruments designated as hedging instruments reported before netting adjustments, and the amount of gain (loss) on derivative instruments and nonderivative instruments designated and qualified as hedging instruments.",
        "label": "Derivative Instruments, Gain (Loss) [Table]"
       }
      }
     },
     "localname": "DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesCumulativeBasisAdjustmentForFairValueHedgesDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DerivativeInstrumentsGainLossLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Derivative Instruments, Gain (Loss) [Line Items]",
        "terseLabel": "DERIVATIVES"
       }
      }
     },
     "localname": "DerivativeInstrumentsGainLossLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesCumulativeBasisAdjustmentForFairValueHedgesDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DerivativeLiabilities": {
     "auth_ref": [
      "r30",
      "r35",
      "r40",
      "r541"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeLiabilitiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.",
        "label": "Derivative Liability",
        "terseLabel": "Interest rate swaps",
        "totalLabel": "Net Amounts of Liabilities Presented in the Statement of Financial Position"
       }
      }
     },
     "localname": "DerivativeLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeLiabilitiesDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Derivative [Line Items]",
        "terseLabel": "Derivative [Line Items]"
       }
      }
     },
     "localname": "DerivativeLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DerivativeMember": {
     "auth_ref": [
      "r469"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This element represents types of derivative financial instruments which are financial instruments or other contractual arrangements with all three of the following characteristics: (a) it has (1) one or more underlyings and (2) one or more notional amounts or payment provisions or both. Those terms determine the amount of the settlement or settlements, and, in some cases, whether or not a settlement is required; (b) it requires no initial net investment or an initial net investment that is smaller than would be required for other types of contracts that would be expected to have a similar response to changes in market factors; and (c) its terms require or permit net settlement, it can readily be settled net by a means outside the contract, or it provides for delivery of an asset that puts the recipient in a position not substantially different from net settlement. Notwithstanding the above characteristics, loan commitments that relate to the origination of mortgage loans that will be held for sale are accounted for as derivative instruments by the issuer of the loan commitment (that is, the potential lender).",
        "label": "Derivative"
       }
      }
     },
     "localname": "DerivativeMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DerivativeNetLiabilityPositionAggregateFairValue": {
     "auth_ref": [
      "r495"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument.",
        "label": "Derivative, Net Liability Position, Aggregate Fair Value",
        "terseLabel": "Derivative, net liability position"
       }
      }
     },
     "localname": "DerivativeNetLiabilityPositionAggregateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesCreditRiskRelatedContingentFeaturesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeNotionalAmount": {
     "auth_ref": [
      "r472",
      "r474"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Nominal or face amount used to calculate payment on derivative.",
        "label": "Derivative, Notional Amount",
        "terseLabel": "Notional"
       }
      }
     },
     "localname": "DerivativeNotionalAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DerivativeTable": {
     "auth_ref": [
      "r471",
      "r473",
      "r474",
      "r477",
      "r478",
      "r484",
      "r489",
      "r498",
      "r500",
      "r507",
      "r509"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule that describes and identifies a derivative or group of derivatives on a disaggregated basis, such as for individual instruments, or small groups of similar instruments. May include a combination of the type of instrument, risks being hedged, notional amount, hedge designation, related hedged item, inception date, maturity date, or other relevant item.",
        "label": "Derivative [Table]",
        "terseLabel": "Derivative [Table]"
       }
      }
     },
     "localname": "DerivativeTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DesignatedAsHedgingInstrumentMember": {
     "auth_ref": [
      "r477"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Derivative instrument designated as hedging instrument under Generally Accepted Accounting Principles (GAAP).",
        "label": "Designated as Hedging Instrument"
       }
      }
     },
     "localname": "DesignatedAsHedgingInstrumentMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DisaggregationOfRevenueTableTextBlock": {
     "auth_ref": [
      "r382"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of disaggregation of revenue into categories depicting how nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factor.",
        "label": "Disaggregation of Revenue [Table Text Block]",
        "terseLabel": "Schedule of noninterest income, segregated by revenue streams in-scope and out-of-scope of Topic 606"
       }
      }
     },
     "localname": "DisaggregationOfRevenueTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomersTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock": {
     "auth_ref": [
      "r445"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for share-based payment arrangement.",
        "label": "Disclosure of Compensation Related Costs, Share-based Payments [Text Block]",
        "terseLabel": "Stock-Based Compensation"
       }
      }
     },
     "localname": "DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensation"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "STOCK-BASED COMPENSATION"
       }
      }
     },
     "localname": "DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_DividendsCommonStockCash": {
     "auth_ref": [
      "r372"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.",
        "label": "Dividends, Common Stock, Cash",
        "negatedLabel": "Dividends paid"
       }
      }
     },
     "localname": "DividendsCommonStockCash",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EarningsPerShareAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "EARNINGS PER SHARE"
       }
      }
     },
     "localname": "EarningsPerShareAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_EarningsPerShareBasic": {
     "auth_ref": [
      "r66",
      "r114",
      "r115",
      "r117",
      "r118",
      "r119",
      "r125",
      "r127",
      "r133",
      "r135",
      "r136",
      "r140",
      "r141",
      "r519",
      "r520",
      "r668",
      "r714"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.",
        "label": "Earnings Per Share, Basic",
        "terseLabel": "Basic earnings per share (in dollars per share)"
       }
      }
     },
     "localname": "EarningsPerShareBasic",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesErrorCorrectionsDetails",
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareScheduleOfEarningsPerShareBasicAndDilutedDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_EarningsPerShareDiluted": {
     "auth_ref": [
      "r66",
      "r114",
      "r115",
      "r117",
      "r118",
      "r119",
      "r127",
      "r133",
      "r135",
      "r136",
      "r140",
      "r141",
      "r519",
      "r520",
      "r668",
      "r714"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.",
        "label": "Earnings Per Share, Diluted",
        "terseLabel": "Diluted earnings per share (in dollars per share)"
       }
      }
     },
     "localname": "EarningsPerShareDiluted",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesErrorCorrectionsDetails",
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareScheduleOfEarningsPerShareBasicAndDilutedDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_EarningsPerSharePolicyTextBlock": {
     "auth_ref": [
      "r137",
      "r138"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy for computing basic and diluted earnings or loss per share for each class of common stock and participating security. Addresses all significant policy factors, including any antidilutive items that have been excluded from the computation and takes into account stock dividends, splits and reverse splits that occur after the balance sheet date of the latest reporting period but before the issuance of the financial statements.",
        "label": "Earnings Per Share, Policy [Policy Text Block]",
        "terseLabel": "Earnings Per Share"
       }
      }
     },
     "localname": "EarningsPerSharePolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_EarningsPerShareTextBlock": {
     "auth_ref": [
      "r137",
      "r138",
      "r139",
      "r142"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for earnings per share.",
        "label": "Earnings Per Share [Text Block]",
        "terseLabel": "EARNINGS PER SHARE"
       }
      }
     },
     "localname": "EarningsPerShareTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEarningsPerShare"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions": {
     "auth_ref": [
      "r428"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cost to be recognized for option under share-based payment arrangement.",
        "label": "Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options",
        "terseLabel": "Unrecognized compensation cost, nonvested awards"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeStockOwnershipPlanESOPCompensationExpense": {
     "auth_ref": [
      "r444"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 6.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of plan compensation cost recognized during the period.",
        "label": "Employee Stock Ownership Plan (ESOP), Compensation Expense",
        "terseLabel": "ESOP compensation expense for allocated shares"
       }
      }
     },
     "localname": "EmployeeStockOwnershipPlanESOPCompensationExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEmployeeBenefitsNarrativeDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeStockOwnershipPlanESOPInterestPaymentsFromESOP": {
     "auth_ref": [
      "r443"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "An entity often discloses the amount of interest paid by the ESOP to a lender.",
        "label": "Employee Stock Ownership Plan (ESOP), Interest Payments from ESOP",
        "terseLabel": "Employee stock ownership plan (ESOP), interest payments from esop"
       }
      }
     },
     "localname": "EmployeeStockOwnershipPlanESOPInterestPaymentsFromESOP",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEmployeeBenefitsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeStockOwnershipPlanESOPWeightedAveragePurchasePriceOfSharesPurchased": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average purchase price of capital shares purchased through an employee stock ownership plan.",
        "label": "Employee Stock Ownership Plan (ESOP), Weighted Average Purchase Price of Shares Purchased",
        "terseLabel": "Employee stock ownership plan (ESOP), weighted average purchase price of shares purchased (in dollars per share)"
       }
      }
     },
     "localname": "EmployeeStockOwnershipPlanESOPWeightedAveragePurchasePriceOfSharesPurchased",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEmployeeBenefitsNarrativeDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_EquipmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tangible personal property used to produce goods and services.",
        "label": "Equipment"
       }
      }
     },
     "localname": "EquipmentMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_EquityComponentDomain": {
     "auth_ref": [
      "r2",
      "r57",
      "r58",
      "r59",
      "r105",
      "r106",
      "r107",
      "r110",
      "r120",
      "r123",
      "r145",
      "r272",
      "r371",
      "r372",
      "r434",
      "r435",
      "r436",
      "r451",
      "r452",
      "r518",
      "r554",
      "r555",
      "r556",
      "r557",
      "r558",
      "r560",
      "r725",
      "r726",
      "r727",
      "r787"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Components of equity are the parts of the total Equity balance including that which is allocated to common, preferred, treasury stock, retained earnings, etc.",
        "label": "Equity Component [Domain]"
       }
      }
     },
     "localname": "EquityComponentDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_EstimateOfFairValueFairValueDisclosureMember": {
     "auth_ref": [
      "r363",
      "r365",
      "r366",
      "r541"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Measured as an estimate of fair value.",
        "label": "Fair Value"
       }
      }
     },
     "localname": "EstimateOfFairValueFairValueDisclosureMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]",
        "terseLabel": "Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsLoansIndividuallyEvaluatedOreoAndServicingRightsOnNonRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsTables"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable": {
     "auth_ref": [
      "r522",
      "r523",
      "r524",
      "r535"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about asset and liability measured at fair value on recurring and nonrecurring basis.",
        "label": "Fair Value Measurements, Recurring and Nonrecurring [Table]",
        "terseLabel": "Fair Value Measurements, Recurring and Nonrecurring [Table]"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsLoansIndividuallyEvaluatedOreoAndServicingRightsOnNonRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsTables"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock": {
     "auth_ref": [
      "r525"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of input and valuation technique used to measure fair value and change in valuation approach and technique for each separate class of asset and liability measured on recurring and nonrecurring basis.",
        "label": "Fair Value Inputs, Assets, Quantitative Information [Table Text Block]",
        "verboseLabel": "Valuation assumptions"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsTables",
      "http://www.fsbwa.com/role/DisclosureServicingRightsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]",
        "terseLabel": "Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]"
       }
      }
     },
     "localname": "FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueLevel3OnRecurringBasisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]",
        "terseLabel": "Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]"
       }
      }
     },
     "localname": "FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueLevel3OnRecurringBasisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable": {
     "auth_ref": [
      "r528",
      "r535"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule of information required and determined to be provided for purposes of reconciling beginning and ending balances of fair value measurements of assets using significant unobservable inputs (level 3). Such reconciliation, separately presenting changes during the period, at a minimum, may include, but is not limited to: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets) and gains or losses recognized in other comprehensive income, and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issues, and settlements (each type disclosed separately); and (3) transfers in and transfers out of level 3 (for example, transfers due to changes in the observability of significant inputs), by class of asset.",
        "label": "Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table]",
        "terseLabel": "Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table]"
       }
      }
     },
     "localname": "FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueLevel3OnRecurringBasisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]",
        "terseLabel": "Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]"
       }
      }
     },
     "localname": "FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByBalanceSheetGroupingTable": {
     "auth_ref": [
      "r522",
      "r542",
      "r543"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about the fair value of financial instruments, including financial assets and financial liabilities, and the measurements of those instruments, assets, and liabilities.",
        "label": "Fair Value, by Balance Sheet Grouping [Table]",
        "terseLabel": "Fair Value, by Balance Sheet Grouping [Table]"
       }
      }
     },
     "localname": "FairValueByBalanceSheetGroupingTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByBalanceSheetGroupingTextBlock": {
     "auth_ref": [
      "r522",
      "r542"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the fair value of financial instruments, including financial assets and financial liabilities, and the measurements of those instruments, assets, and liabilities.",
        "label": "Fair Value, by Balance Sheet Grouping [Table Text Block]",
        "terseLabel": "Fair Value, by Balance Sheet Grouping"
       }
      }
     },
     "localname": "FairValueByBalanceSheetGroupingTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueByFairValueHierarchyLevelAxis": {
     "auth_ref": [
      "r363",
      "r365",
      "r366",
      "r390",
      "r391",
      "r392",
      "r393",
      "r394",
      "r395",
      "r396",
      "r397",
      "r523",
      "r587",
      "r588",
      "r589"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by level within fair value hierarchy and fair value measured at net asset value per share as practical expedient.",
        "label": "Fair Value, Hierarchy [Axis]"
       }
      }
     },
     "localname": "FairValueByFairValueHierarchyLevelAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsLoansIndividuallyEvaluatedOreoAndServicingRightsOnNonRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsTables"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByMeasurementBasisAxis": {
     "auth_ref": [
      "r363",
      "r365",
      "r366",
      "r522",
      "r536"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by measurement basis.",
        "label": "Measurement Basis [Axis]"
       }
      }
     },
     "localname": "FairValueByMeasurementBasisAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByMeasurementFrequencyAxis": {
     "auth_ref": [
      "r522",
      "r523",
      "r526",
      "r527",
      "r537"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by measurement frequency.",
        "label": "Measurement Frequency [Axis]"
       }
      }
     },
     "localname": "FairValueByMeasurementFrequencyAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsLoansIndividuallyEvaluatedOreoAndServicingRightsOnNonRecurringBasisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueDisclosureOffbalanceSheetRisksAmountAsset": {
     "auth_ref": [
      "r541"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The fair value of financial assets, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.",
        "label": "Fair Value Disclosure, Off-balance Sheet Risks, Amount, Asset",
        "terseLabel": "Fair market value of servicing rights' assets"
       }
      }
     },
     "localname": "FairValueDisclosureOffbalanceSheetRisksAmountAsset",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueDisclosureOffbalanceSheetRisksFaceAmountAsset": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The face amount of financial assets, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.",
        "label": "Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Asset",
        "terseLabel": "The unpaid principal balances of mortgage loans serviced",
        "verboseLabel": "Commitments"
       }
      }
     },
     "localname": "FairValueDisclosureOffbalanceSheetRisksFaceAmountAsset",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "FAIR VALUE MEASUREMENTS"
       }
      }
     },
     "localname": "FairValueDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueDisclosuresTextBlock": {
     "auth_ref": [
      "r533"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.",
        "label": "Fair Value Disclosures [Text Block]",
        "terseLabel": "FAIR VALUE MEASUREMENTS"
       }
      }
     },
     "localname": "FairValueDisclosuresTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurements"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueHedgesAtFairValueNet": {
     "auth_ref": [
      "r470"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Net fair value of all derivative instruments designated as fair value hedging instruments.",
        "label": "Fair Value Hedges, Net",
        "terseLabel": "Fair value hedges"
       }
      }
     },
     "localname": "FairValueHedgesAtFairValueNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesCumulativeBasisAdjustmentForFairValueHedgesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueHedgingMember": {
     "auth_ref": [
      "r475"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A hedge of the exposure to changes in the fair value of a recognized asset or liability, or of an unrecognized firm commitment, that are attributable to a particular risk.",
        "label": "Fair Value Hedging [Member]",
        "terseLabel": "Fair Value Hedges"
       }
      }
     },
     "localname": "FairValueHedgingMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesCumulativeBasisAdjustmentForFairValueHedgesDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueInputsLevel1Member": {
     "auth_ref": [
      "r363",
      "r390",
      "r391",
      "r396",
      "r397",
      "r523",
      "r587"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Quoted prices in active markets for identical assets or liabilities that the reporting entity can access at the measurement date.",
        "label": "Level 1"
       }
      }
     },
     "localname": "FairValueInputsLevel1Member",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsLoansIndividuallyEvaluatedOreoAndServicingRightsOnNonRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueInputsLevel2Member": {
     "auth_ref": [
      "r363",
      "r365",
      "r366",
      "r390",
      "r391",
      "r396",
      "r397",
      "r523",
      "r588"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Inputs other than quoted prices included within level 1 that are observable for an asset or liability, either directly or indirectly, including, but not limited to, quoted prices for similar assets or liabilities in active markets, or quoted prices for identical or similar assets or liabilities in inactive markets.",
        "label": "Level 2"
       }
      }
     },
     "localname": "FairValueInputsLevel2Member",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsLoansIndividuallyEvaluatedOreoAndServicingRightsOnNonRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueInputsLevel3Member": {
     "auth_ref": [
      "r363",
      "r365",
      "r366",
      "r390",
      "r391",
      "r392",
      "r393",
      "r394",
      "r395",
      "r396",
      "r397",
      "r523",
      "r589"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Level 3"
       }
      }
     },
     "localname": "FairValueInputsLevel3Member",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsLoansIndividuallyEvaluatedOreoAndServicingRightsOnNonRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsTables"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations": {
     "auth_ref": [
      "r522",
      "r523"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of subordinated debt obligations including, but not limited to, subordinated loan, subordinated bond, subordinated debenture or junior debt.",
        "label": "Subordinated Debt Obligations, Fair Value Disclosure",
        "terseLabel": "Subordinated notes, excluding unamortized debt issuance costs"
       }
      }
     },
     "localname": "FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueMeasurementFrequencyDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Measurement frequency.",
        "label": "Fair Value, Measurement Frequency [Domain]"
       }
      }
     },
     "localname": "FairValueMeasurementFrequencyDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsLoansIndividuallyEvaluatedOreoAndServicingRightsOnNonRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1": {
     "auth_ref": [
      "r529"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).",
        "label": "Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings",
        "terseLabel": "Net change in fair value for gains/(losses) relating to items held at end of period included in income"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueLevel3OnRecurringBasisDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss": {
     "auth_ref": [
      "r530"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of gain (loss) recognized in other comprehensive income (OCI) from asset measured at fair value on recurring basis using unobservable input (level 3).",
        "label": "Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)",
        "terseLabel": "Net change in fair value for gains/(losses) relating to items held at end of period included in other comprehensive"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueLevel3OnRecurringBasisDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases": {
     "auth_ref": [
      "r531"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases",
        "terseLabel": "Purchases and Issuances"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueLevel3OnRecurringBasisDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements": {
     "auth_ref": [
      "r531"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements",
        "negatedTerseLabel": "Sales and Settlements"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueLevel3OnRecurringBasisDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue": {
     "auth_ref": [
      "r528"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value",
        "periodEndLabel": "Ending Balance",
        "periodStartLabel": "Beginning Balance"
       }
      }
     },
     "localname": "FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueLevel3OnRecurringBasisDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueMeasurementsFairValueHierarchyDomain": {
     "auth_ref": [
      "r363",
      "r365",
      "r366",
      "r390",
      "r391",
      "r392",
      "r393",
      "r394",
      "r395",
      "r396",
      "r397",
      "r587",
      "r588",
      "r589"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Categories used to prioritize the inputs to valuation techniques to measure fair value.",
        "label": "Fair Value, Measurements, Fair Value Hierarchy [Domain]"
       }
      }
     },
     "localname": "FairValueMeasurementsFairValueHierarchyDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsLoansIndividuallyEvaluatedOreoAndServicingRightsOnNonRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsTables"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueMeasurementsNonrecurringMember": {
     "auth_ref": [
      "r522",
      "r523",
      "r526",
      "r527",
      "r532",
      "r537"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Infrequent fair value measurement. Includes, but is not limited to, fair value adjustment for impairment of asset, liability or equity, not frequently measured at fair value.",
        "label": "Fair Value, Measurements, Nonrecurring"
       }
      }
     },
     "localname": "FairValueMeasurementsNonrecurringMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsLoansIndividuallyEvaluatedOreoAndServicingRightsOnNonRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueMeasurementsRecurringMember": {
     "auth_ref": [
      "r533",
      "r537"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Frequent fair value measurement. Includes, but is not limited to, fair value adjustment for impairment of asset, liability or equity, frequently measured at fair value.",
        "label": "Fair Value, Measurements, Recurring"
       }
      }
     },
     "localname": "FairValueMeasurementsRecurringMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTableTextBlock": {
     "auth_ref": [
      "r528",
      "r534"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of financial instrument classified as a derivative asset (liability) after deduction of derivative liability (asset) using recurring unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.",
        "label": "Fair Value, Instruments Classified in Shareholders' Equity Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]",
        "verboseLabel": "Fair value reconciliation - Level 3 on recurring basis"
       }
      }
     },
     "localname": "FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputReconciliationTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueOfAssetsAcquired": {
     "auth_ref": [
      "r94",
      "r95",
      "r96"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The fair value of assets acquired in noncash investing or financing activities.",
        "label": "Fair Value of Assets Acquired",
        "terseLabel": "OREO received in settlement of loans"
       }
      }
     },
     "localname": "FairValueOfAssetsAcquired",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FairValueOfFinancialInstrumentsPolicy": {
     "auth_ref": [
      "r538",
      "r540"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy for determining the fair value of financial instruments.",
        "label": "Fair Value of Financial Instruments, Policy [Policy Text Block]",
        "terseLabel": "Determination of Fair Market Values"
       }
      }
     },
     "localname": "FairValueOfFinancialInstrumentsPolicy",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueOffBalanceSheetRisksDisclosureInformationLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]",
        "terseLabel": "Off-balance Sheet Risks, Disclosure Information [Line Items]"
       }
      }
     },
     "localname": "FairValueOffBalanceSheetRisksDisclosureInformationLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsTables",
      "http://www.fsbwa.com/role/DisclosureServicingRightsValuationAssumptionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FederalDepositInsuranceCorporationPremiumExpense": {
     "auth_ref": [
      "r678"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_NoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of expense for Federal Deposit Insurance Corporation (FDIC) insurance.",
        "label": "Federal Deposit Insurance Corporation Premium Expense",
        "terseLabel": "Federal Deposit Insurance Corporation (\"FDIC\") insurance"
       }
      }
     },
     "localname": "FederalDepositInsuranceCorporationPremiumExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FederalHomeLoanBankStock": {
     "auth_ref": [
      "r691"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 5.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).",
        "label": "Federal Home Loan Bank Stock.",
        "terseLabel": "Federal Home Loan Bank (\"FHLB\") stock, at cost"
       }
      }
     },
     "localname": "FederalHomeLoanBankStock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FederalHomeLoanMortgageCorporationFhlmcInsuredLoansMember": {
     "auth_ref": [
      "r743",
      "r744"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Government-sponsored enterprise under conservatorship of Federal Housing Finance Agency known as Federal Home Loan Mortgage Corporation (FHLMC or Freddie Mac).",
        "label": "Federal Home Loan Mortgage Corporation (\"FHLMC\")"
       }
      }
     },
     "localname": "FederalHomeLoanMortgageCorporationFhlmcInsuredLoansMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FederalNationalMortgageAssociationFnmaInsuredLoansMember": {
     "auth_ref": [
      "r743",
      "r744"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Government-sponsored enterprise under conservatorship of Federal Housing Finance Agency known as Federal National Mortgage Association (FNMA or Fannie Mae).",
        "label": "Federal National Mortgage Association (\"FNMA\")"
       }
      }
     },
     "localname": "FederalNationalMortgageAssociationFnmaInsuredLoansMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FinancialAssetNotPastDueMember": {
     "auth_ref": [
      "r284",
      "r302"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financial asset not past due.",
        "label": "Not Past Due"
       }
      }
     },
     "localname": "FinancialAssetNotPastDueMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FinancialAssetPastDueMember": {
     "auth_ref": [
      "r214",
      "r284",
      "r302"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financial asset past due.",
        "label": "Past Due"
       }
      }
     },
     "localname": "FinancialAssetPastDueMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FinancialInstrumentAxis": {
     "auth_ref": [
      "r247",
      "r251",
      "r264",
      "r265",
      "r266",
      "r277",
      "r283",
      "r284",
      "r288",
      "r292",
      "r308",
      "r310",
      "r311",
      "r312",
      "r364",
      "r370",
      "r509",
      "r584",
      "r585",
      "r586",
      "r587",
      "r588",
      "r589",
      "r591",
      "r592",
      "r593",
      "r598",
      "r599",
      "r600",
      "r601",
      "r605",
      "r609",
      "r619",
      "r620",
      "r621",
      "r622",
      "r626",
      "r627",
      "r628",
      "r629",
      "r630",
      "r631",
      "r632",
      "r633",
      "r636",
      "r637",
      "r638",
      "r765",
      "r766",
      "r767",
      "r768",
      "r769",
      "r770",
      "r771"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of financial instrument.",
        "label": "Financial Instrument [Axis]"
       }
      }
     },
     "localname": "FinancialInstrumentAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAllowanceForCreditLossesDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAmortizedCostOfDebtDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsTables",
      "http://www.fsbwa.com/role/DisclosureServicingRightsValuationAssumptionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]",
        "terseLabel": "Financial Assets"
       }
      }
     },
     "localname": "FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]",
        "terseLabel": "Financial Liabilities"
       }
      }
     },
     "localname": "FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancialLiabilitiesFairValueDisclosure": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities.",
        "label": "Financial Liabilities Fair Value Disclosure",
        "negatedLabel": "Total liabilities measured at fair value"
       }
      }
     },
     "localname": "FinancialLiabilitiesFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableAccruedInterestAfterAllowanceForCreditLoss": {
     "auth_ref": [
      "r276",
      "r289"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of accrued interest on financing receivable.",
        "label": "Financing Receivable, Accrued Interest, after Allowance for Credit Loss",
        "terseLabel": "Accrued interest on loans"
       }
      }
     },
     "localname": "FinancingReceivableAccruedInterestAfterAllowanceForCreditLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableAllowanceForCreditLosses": {
     "auth_ref": [
      "r193",
      "r275",
      "r278",
      "r282",
      "r656",
      "r775",
      "r777",
      "r779"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.",
        "label": "Financing Receivable, Allowance for Credit Losses",
        "periodEndLabel": "Ending balance",
        "periodStartLabel": "Beginning balance",
        "totalLabel": "Ending balance"
       }
      }
     },
     "localname": "FinancingReceivableAllowanceForCreditLosses",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment": {
     "auth_ref": [
      "r197"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_FinancingReceivableAllowanceForCreditLosses",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.",
        "label": "Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment",
        "terseLabel": "Loans collectively evaluated for impairment"
       }
      }
     },
     "localname": "FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1": {
     "auth_ref": [
      "r197"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_FinancingReceivableAllowanceForCreditLosses",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.",
        "label": "Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment",
        "terseLabel": "Loans individually evaluated for impairment"
       }
      }
     },
     "localname": "FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Financing Receivable, Allowance for Credit Losses [Line Items]",
        "terseLabel": "Financing Receivable, Allowance for Credit Losses [Line Items]"
       }
      }
     },
     "localname": "FinancingReceivableAllowanceForCreditLossesLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancingReceivableAllowanceForCreditLossesPeriodIncreaseDecrease": {
     "auth_ref": [
      "r192",
      "r283"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in allowance for credit loss on financing receivable.",
        "label": "Financing Receivable, Allowance for Credit Loses, Recovery (Write-downs), Net",
        "totalLabel": "Net charge-offs"
       }
      }
     },
     "localname": "FinancingReceivableAllowanceForCreditLossesPeriodIncreaseDecrease",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery": {
     "auth_ref": [
      "r196",
      "r281",
      "r301"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_FinancingReceivableAllowanceForCreditLossesPeriodIncreaseDecrease",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase in allowance for credit loss on financing receivable from recovery.",
        "label": "Financing Receivable, Allowance for Credit Losses, Recovery",
        "terseLabel": "Recoveries"
       }
      }
     },
     "localname": "FinancingReceivableAllowanceForCreditLossesRecovery",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Financing Receivable, Allowance for Credit Losses [Roll Forward]",
        "verboseLabel": "ALLOWANCE FOR LOAN LOSSES"
       }
      }
     },
     "localname": "FinancingReceivableAllowanceForCreditLossesRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs": {
     "auth_ref": [
      "r195",
      "r280",
      "r301"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_FinancingReceivableAllowanceForCreditLossesPeriodIncreaseDecrease",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of writeoff of financing receivable, charged against allowance for credit loss.",
        "label": "Financing Receivable, Allowance for Credit Losses, Write-downs",
        "negatedLabel": "Loans charged-off"
       }
      }
     },
     "localname": "FinancingReceivableAllowanceForCreditLossesWriteOffs",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment": {
     "auth_ref": [
      "r198"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_LoansAndLeasesReceivableGrossCarryingAmount",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The balance of financing receivables that were collectively evaluated for impairment.",
        "label": "Financing Receivable, Collectively Evaluated for Impairment",
        "terseLabel": "Loans collectively evaluated for impairment"
       }
      }
     },
     "localname": "FinancingReceivableCollectivelyEvaluatedForImpairment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableCreditQualityIndicatorsTableTextBlock": {
     "auth_ref": [
      "r207",
      "r292"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of financing receivables by credit quality indicator. The credit quality indicator is a statistic about the credit quality of financing receivables. Examples include, but not limited to, consumer credit risk scores, credit-rating-agency ratings, an entity's internal credit risk grades, loan-to-value ratios, collateral, collection experience and other internal metrics.",
        "label": "Financing Receivable Credit Quality Indicators [Table Text Block]",
        "terseLabel": "Summarize risk rated loan balances"
       }
      }
     },
     "localname": "FinancingReceivableCreditQualityIndicatorsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FinancingReceivableImpairedLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Financing Receivable, Impaired [Line Items]",
        "terseLabel": "Financing Receivable, Impaired [Line Items]"
       }
      }
     },
     "localname": "FinancingReceivableImpairedLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment": {
     "auth_ref": [
      "r198"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_LoansAndLeasesReceivableGrossCarryingAmount",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The balance of financing receivables that were individually evaluated for impairment.",
        "label": "Financing Receivable, Individually Evaluated for Impairment",
        "terseLabel": "Loans individually evaluated for impairment"
       }
      }
     },
     "localname": "FinancingReceivableIndividuallyEvaluatedForImpairment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableNonaccrualInterestIncome": {
     "auth_ref": [
      "r286"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest income on financing receivable on nonaccrual status.",
        "label": "Financing Receivable, Nonaccrual, Interest Income",
        "terseLabel": "Recognized interest income on nonaccrual loans"
       }
      }
     },
     "localname": "FinancingReceivableNonaccrualInterestIncome",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableNonaccrualNoAllowance": {
     "auth_ref": [
      "r287"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of financing receivable on nonaccrual status with no allowance for credit loss.",
        "label": "Financing Receivable, Nonaccrual, No Allowance",
        "terseLabel": "Nonaccrual with no Allowance for Credit Losses"
       }
      }
     },
     "localname": "FinancingReceivableNonaccrualNoAllowance",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear": {
     "auth_ref": [
      "r293",
      "r301"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of financing receivable originated more than five years prior to current fiscal year.",
        "label": "Financing Receivable, Originated, More than Five Years before Current Fiscal Year",
        "terseLabel": "Prior"
       }
      }
     },
     "localname": "FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear": {
     "auth_ref": [
      "r293",
      "r301"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of financing receivable originated four years prior to current fiscal year.",
        "label": "Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year",
        "terseLabel": "2018"
       }
      }
     },
     "localname": "FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear": {
     "auth_ref": [
      "r293",
      "r301"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of financing receivable originated in current fiscal year.",
        "label": "Financing Receivable, Year One, Originated, Current Fiscal Year",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "FinancingReceivableOriginatedInCurrentFiscalYear",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear": {
     "auth_ref": [
      "r293",
      "r301"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of financing receivable originated in fiscal year prior to current fiscal year.",
        "label": "Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year",
        "terseLabel": "2021"
       }
      }
     },
     "localname": "FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear": {
     "auth_ref": [
      "r293",
      "r301"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of financing receivable originated three years prior to current fiscal year.",
        "label": "Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year",
        "terseLabel": "2019"
       }
      }
     },
     "localname": "FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear": {
     "auth_ref": [
      "r293",
      "r301"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of financing receivable originated two years prior to current fiscal year.",
        "label": "Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year",
        "terseLabel": "2020"
       }
      }
     },
     "localname": "FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivablePortfolioSegmentAxis": {
     "auth_ref": [
      "r277",
      "r283",
      "r294",
      "r765",
      "r766",
      "r767",
      "r768",
      "r769",
      "r770",
      "r771",
      "r773",
      "r774",
      "r775",
      "r776",
      "r777",
      "r778",
      "r779"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by the level at which an entity develops and documents a systematic methodology to determine its allowance for credit losses.",
        "label": "Financing Receivable Portfolio Segment [Axis]"
       }
      }
     },
     "localname": "FinancingReceivablePortfolioSegmentAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancingReceivablePortfolioSegmentDomain": {
     "auth_ref": [
      "r765",
      "r766",
      "r767",
      "r768",
      "r769",
      "r770",
      "r771",
      "r773",
      "r774",
      "r775",
      "r776",
      "r777",
      "r778",
      "r779"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Level at which an entity develops and documents a systematic methodology to determine its allowance for credit losses.",
        "label": "Financing Receivable Portfolio Segment [Domain]"
       }
      }
     },
     "localname": "FinancingReceivablePortfolioSegmentDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis": {
     "auth_ref": [
      "r208",
      "r213",
      "r214",
      "r284",
      "r288",
      "r292",
      "r295",
      "r296",
      "r301",
      "r302",
      "r765",
      "r766",
      "r767",
      "r768",
      "r769",
      "r770",
      "r771",
      "r773",
      "r774",
      "r775",
      "r776",
      "r777",
      "r778",
      "r779"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by class of financing receivable determined on the basis of initial measurement attribute, risk characteristics and method of monitoring and assessing credit risk.",
        "label": "Class of Financing Receivable, Type [Axis]"
       }
      }
     },
     "localname": "FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain": {
     "auth_ref": [
      "r765",
      "r766",
      "r767",
      "r768",
      "r769",
      "r770",
      "r771",
      "r773",
      "r774",
      "r775",
      "r776",
      "r777",
      "r778",
      "r779"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financing receivables determined on the basis of initial measurement attribute, risk characteristics and method of monitoring and assessing credit risk.",
        "label": "Class of Financing Receivable [Domain]"
       }
      }
     },
     "localname": "FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FinancingReceivableRecordedInvestmentLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Financing Receivable, Recorded Investment [Line Items]",
        "terseLabel": "Financing Receivable, Recorded Investment [Line Items]"
       }
      }
     },
     "localname": "FinancingReceivableRecordedInvestmentLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAmortizedCostOfDebtDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus": {
     "auth_ref": [
      "r212",
      "r285",
      "r776",
      "r777"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of financing receivable on nonaccrual status.",
        "label": "Financing Receivable, Recorded Investment, Nonaccrual Status",
        "terseLabel": "Non-Accrual",
        "verboseLabel": "Total Nonaccrual"
       }
      }
     },
     "localname": "FinancingReceivableRecordedInvestmentNonaccrualStatus",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Financing Receivable, Recorded Investment, Past Due [Line Items]"
       }
      }
     },
     "localname": "FinancingReceivableRecordedInvestmentPastDueLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancingReceivableRevolving": {
     "auth_ref": [
      "r293",
      "r301"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of financing receivable that can be withdrawn, repaid and redrawn.",
        "label": "Financing Receivable, Revolving",
        "terseLabel": "Revolving Loans"
       }
      }
     },
     "localname": "FinancingReceivableRevolving",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount": {
     "auth_ref": [
      "r210",
      "r218",
      "r219"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of unamortized loan commitment, origination, and other fees (costs) and purchase premium (discount) on financing receivable. Excludes financing receivable covered under loss sharing agreement.",
        "label": "Financing Receivable, Unamortized Loan Fee (Cost) and Purchase Premium (Discount)",
        "terseLabel": "Unamortized costs and premiums"
       }
      }
     },
     "localname": "FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FinancingReceivables30To59DaysPastDueMember": {
     "auth_ref": [
      "r302"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financial asset more than 29 days past due but fewer than 60 days past due.",
        "label": "30-59 Days Past Due"
       }
      }
     },
     "localname": "FinancingReceivables30To59DaysPastDueMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FinancingReceivables60To89DaysPastDueMember": {
     "auth_ref": [
      "r302"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financial asset more than 59 days past due but fewer than 90 days past due.",
        "label": "60-89 Days Past Due"
       }
      }
     },
     "localname": "FinancingReceivables60To89DaysPastDueMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember": {
     "auth_ref": [
      "r302"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financial asset equal to or greater than 90 days past due.",
        "label": "90 Days or More Past Due"
       }
      }
     },
     "localname": "FinancingReceivablesEqualToGreaterThan90DaysPastDueMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FinancingReceivablesPeriodPastDueAxis": {
     "auth_ref": [
      "r214",
      "r284",
      "r302"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by period in which financial asset is past due or not past due.",
        "label": "Financing Receivables, Period Past Due [Axis]"
       }
      }
     },
     "localname": "FinancingReceivablesPeriodPastDueAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancingReceivablesPeriodPastDueDomain": {
     "auth_ref": [
      "r214",
      "r284",
      "r302"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period in which financial asset is past due or not past due. For past due, element name and standard label in Financial Asset, [numeric lower end] to [numeric higher end] [date measure] Past Due [Member] or Financial Asset, Greater than [low end numeric value] [date measure] Past Due [Member] or Financial Asset, Less than [high end numeric value] [date measure] Past Due [Member] formats.",
        "label": "Financing Receivables, Period Past Due [Domain]"
       }
      }
     },
     "localname": "FinancingReceivablesPeriodPastDueDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FinancingReceivablesTextBlock": {
     "auth_ref": [
      "r217",
      "r222"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for financing receivable.",
        "label": "Financing Receivables [Text Block]",
        "terseLabel": "LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS"
       }
      }
     },
     "localname": "FinancingReceivablesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoans"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetUsefulLife": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Finite-Lived Intangible Asset, Useful Life",
        "terseLabel": "Amortization period - CDI"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetUsefulLife",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization": {
     "auth_ref": [
      "r322"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetailsCalc2": {
       "order": 1.0,
       "parentTag": "us-gaap_FiniteLivedIntangibleAssetsNet",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.",
        "label": "Finite-Lived Intangible Assets, Accumulated Amortization",
        "negatedPeriodEndLabel": "Finite-Lived Intangible Assets, Accumulated Amortization",
        "negatedPeriodStartLabel": "Finite-Lived Intangible Assets, Accumulated Amortization"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAccumulatedAmortization",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths": {
     "auth_ref": [
      "r324"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_FiniteLivedIntangibleAssetsNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_FiniteLivedIntangibleAssetsNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in remainder of current fiscal year.",
        "label": "Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year",
        "terseLabel": "Remainder of 2022"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour": {
     "auth_ref": [
      "r324"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_FiniteLivedIntangibleAssetsNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Finite-Lived Intangible Assets, Amortization Expense, Year Four",
        "verboseLabel": "2026"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseYearFour",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree": {
     "auth_ref": [
      "r324"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_FiniteLivedIntangibleAssetsNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Finite-Lived Intangible Assets, Amortization Expense, Year Three",
        "verboseLabel": "2025"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseYearThree",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo": {
     "auth_ref": [
      "r324"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_FiniteLivedIntangibleAssetsNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of amortization for assets, excluding financial assets and goodwill, lacking physical substance with finite life expected to be recognized in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Finite-Lived Intangible Assets, Amortization Expense, Year Two",
        "verboseLabel": "2024"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsGross": {
     "auth_ref": [
      "r322",
      "r646"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetailsCalc2": {
       "order": 2.0,
       "parentTag": "us-gaap_FiniteLivedIntangibleAssetsNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.",
        "label": "Finite-Lived Intangible Assets, Gross",
        "periodEndLabel": "Finite-Lived Intangible Assets, Gross, Total",
        "periodStartLabel": "Finite-Lived Intangible Assets, Gross, Total"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsGross",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Finite-Lived Intangible Assets [Line Items]"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsNet": {
     "auth_ref": [
      "r322",
      "r642"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetailsCalc2": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 17.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.",
        "label": "Finite-Lived Intangible Assets, Net",
        "periodEndLabel": "Finite-Lived Intangible Assets, Net, Ending Balance",
        "periodStartLabel": "Finite-Lived Intangible Assets, Net, Beginning Balance",
        "terseLabel": "Core deposit intangible, net",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsNetAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Finite-Lived Intangible Assets, Net [Abstract]"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsNetAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ForwardContractsMember": {
     "auth_ref": [
      "r490"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Contracts negotiated between two parties to purchase and sell a specific quantity of a financial instrument, foreign currency, or commodity at a price specified at origination of the contract, with delivery and settlement at a specified future date.",
        "label": "Individual forward sale commitments with investors"
       }
      }
     },
     "localname": "ForwardContractsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueLevel3OnRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_GainLossFromComponentsExcludedFromAssessmentOfCashFlowHedgeEffectivenessNet": {
     "auth_ref": [
      "r488"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The net gain (loss) relating to components of the gain (loss) on the cash flow hedging instrument excluded from the assessment of cash flow hedge effectiveness. Recognized in earnings.",
        "label": "Gain (Loss) from Components Excluded from Assessment of Cash Flow Hedge Effectiveness, Net",
        "terseLabel": "Net income (expense) recognized on cash flow hedges"
       }
      }
     },
     "localname": "GainLossFromComponentsExcludedFromAssessmentOfCashFlowHedgeEffectivenessNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GainLossOnSalesOfLoansNet": {
     "auth_ref": [
      "r90",
      "r674",
      "r717"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 3.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The net gain (loss) resulting from a sale of loans, including adjustments to record loans classified as held-for-sale at the lower-of-cost-or-market and fair value adjustments to loan held for investment purposes.",
        "label": "Gain (Loss) on Sales of Loans, Net",
        "verboseLabel": "Gain on sale of loans"
       }
      }
     },
     "localname": "GainLossOnSalesOfLoansNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GainsLossesOnSalesOfOtherRealEstate": {
     "auth_ref": [
      "r677"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 12.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      },
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 4.0,
       "parentTag": "us-gaap_NoninterestExpense",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The net gain (loss) resulting from sales and other disposals of other real estate owned, increases (decreases) in the valuation allowance for foreclosed real estate, and write-downs of other real estate owned after acquisition or physical possession.",
        "label": "Gains (Losses) on Sales of Other Real Estate",
        "negatedLabel": "Loss on sale of OREO",
        "negatedTerseLabel": "Loss on sale of OREO"
       }
      }
     },
     "localname": "GainsLossesOnSalesOfOtherRealEstate",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_Goodwill": {
     "auth_ref": [
      "r313",
      "r315",
      "r583",
      "r651"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 16.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.",
        "label": "Goodwill",
        "terseLabel": "Goodwill"
       }
      }
     },
     "localname": "Goodwill",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "GOODWILL AND OTHER INTANGIBLE ASSETS"
       }
      }
     },
     "localname": "GoodwillAndIntangibleAssetsDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock": {
     "auth_ref": [
      "r325"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for goodwill and intangible assets.",
        "label": "Goodwill and Intangible Assets Disclosure [Text Block]",
        "terseLabel": "GOODWILL AND OTHER INTANGIBLE ASSETS"
       }
      }
     },
     "localname": "GoodwillAndIntangibleAssetsDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssets"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_GoodwillImpairmentLoss": {
     "auth_ref": [
      "r90",
      "r314",
      "r316",
      "r318"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.",
        "label": "Goodwill, Impairment Loss",
        "terseLabel": "Goodwill, Impairment Loss"
       }
      }
     },
     "localname": "GoodwillImpairmentLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GovernmentNationalMortgageAssociationGnmaInsuredLoansMember": {
     "auth_ref": [
      "r743",
      "r744"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Government-owned corporation within Department of Housing and Urban Development known as Government National Mortgage Association (GNMA or Ginnie Mae).",
        "label": "Government National Mortgage Association (\"GNMA\")"
       }
      }
     },
     "localname": "GovernmentNationalMortgageAssociationGnmaInsuredLoansMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_GuaranteeOfIndebtednessOfOthersMember": {
     "auth_ref": [
      "r344",
      "r457",
      "r736"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Agreements (contracts) that contingently require the guarantor to make payments of principal and interest to a lender on another party's debt if that party fails to comply with the terms of the borrowing arrangement.",
        "label": "Guarantee on loans sold"
       }
      }
     },
     "localname": "GuaranteeOfIndebtednessOfOthersMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_HedgingDesignationAxis": {
     "auth_ref": [
      "r477",
      "r494"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by designation of purpose of derivative instrument.",
        "label": "Hedging Designation [Axis]"
       }
      }
     },
     "localname": "HedgingDesignationAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_HedgingDesignationDomain": {
     "auth_ref": [
      "r477"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Designation of purpose of derivative instrument.",
        "label": "Hedging Designation [Domain]"
       }
      }
     },
     "localname": "HedgingDesignationDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_HedgingRelationshipDomain": {
     "auth_ref": [
      "r477"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Nature or intent of a hedge.",
        "label": "Hedging Relationship [Domain]"
       }
      }
     },
     "localname": "HedgingRelationshipDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesCumulativeBasisAdjustmentForFairValueHedgesDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_HeldToMaturitySecurities": {
     "auth_ref": [
      "r214",
      "r239",
      "r275",
      "r284"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails1": {
       "order": 1.0,
       "parentTag": "us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturity",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Held-to-maturity",
        "netLabel": "Securities held-to-maturity",
        "verboseLabel": "Amortized cost"
       }
      }
     },
     "localname": "HeldToMaturitySecurities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]",
        "terseLabel": "SECURITIES HELD-TO-MATURITY"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain": {
     "auth_ref": [
      "r242",
      "r249"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain",
        "terseLabel": "Unrealized gains"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss": {
     "auth_ref": [
      "r243",
      "r250"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss",
        "negatedLabel": "Unrealized losses"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesClassifiedAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Activity in securities held-to-maturity:"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesClassifiedAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss": {
     "auth_ref": [
      "r256"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position.",
        "label": "Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss",
        "negatedLabel": "Securities held-to-maturity, Unrealized losses"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue": {
     "auth_ref": [
      "r255"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position.",
        "label": "Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value",
        "totalLabel": "Securities held-to-maturity, Unrealized loss position, Fair Value"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss": {
     "auth_ref": [
      "r256",
      "r258"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in continuous loss position for less than 12 months.",
        "label": "Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss",
        "negatedLabel": "Securities held-to-maturity, Unrealized loss position, Unrealized losses, Less than 12 Months"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue": {
     "auth_ref": [
      "r258"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (held-to-maturity), in continuous unrealized loss position for less than 12 months.",
        "label": "Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value",
        "terseLabel": "Securities held-to-maturity, Unrealized loss position, Fair Value, Less than 12 Months"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue": {
     "auth_ref": [
      "r246",
      "r252",
      "r683",
      "r687"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10",
        "terseLabel": "Securities held-to-maturity, Due after five years through ten years"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount": {
     "auth_ref": [
      "r246",
      "r683"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Debt Securities, Held-to-Maturity, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10",
        "terseLabel": "Securities held-to-maturity, Due after five years through ten years"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis": {
     "auth_ref": [
      "r245",
      "r684"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_DebtSecurities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) with single maturity date and allocated without single maturity date.",
        "label": "Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost",
        "totalLabel": "Securities held-to-maturity, Total"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue": {
     "auth_ref": [
      "r245",
      "r253",
      "r684",
      "r689"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityFairValue",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date.",
        "label": "Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Fair Value",
        "totalLabel": "Securities held-to-maturity, Total"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HeldToMaturitySecuritiesFairValue": {
     "auth_ref": [
      "r240",
      "r248",
      "r655"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails1": {
       "order": 1.0,
       "parentTag": "us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityFairValue",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of investment in debt security measured at amortized cost (held-to-maturity).",
        "label": "Debt Securities, Held-to-maturity, Fair Value",
        "terseLabel": "Securities held-to-maturity, at fair value"
       }
      }
     },
     "localname": "HeldToMaturitySecuritiesFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_HomeEquityMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Revolving, open-end loan extended under a line of credit and secured by the borrower's residential property.",
        "label": "Home equity."
       }
      }
     },
     "localname": "HomeEquityMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment": {
     "auth_ref": [
      "r203",
      "r206"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.",
        "label": "Impaired Financing Receivable, Average Recorded Investment",
        "totalLabel": "Average Recorded Investment"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableAverageRecordedInvestment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableAverageRecordedInvestmentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Impaired Financing Receivable, Average Recorded Investment [Abstract]",
        "terseLabel": "Impaired Financing Receivable, Average Recorded Investment [Abstract]"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableAverageRecordedInvestmentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod": {
     "auth_ref": [
      "r204"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.",
        "label": "Impaired Financing Receivable, Interest Income, Accrual Method",
        "totalLabel": "Interest Income Recognized"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableInterestIncomeAccrualMethod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethodAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Impaired Financing Receivable, Interest Income, Accrual Method [Abstract]",
        "terseLabel": "Impaired Financing Receivable, Interest Income [Abstract]"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableInterestIncomeAccrualMethodAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ImpairedFinancingReceivableRecordedInvestment": {
     "auth_ref": [
      "r200"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.",
        "label": "Impaired Financing Receivable, Recorded Investment",
        "totalLabel": "Recorded Investment"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableRecordedInvestment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableRecordedInvestmentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Impaired Financing Receivable, Recorded Investment [Abstract]",
        "terseLabel": "Impaired Financing Receivable, Recorded Investment [Abstract]"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableRecordedInvestmentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ImpairedFinancingReceivableRelatedAllowance": {
     "auth_ref": [
      "r201"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of allowance for credit losses related to recorded investment.",
        "label": "Impaired Financing Receivable, Related Allowance",
        "totalLabel": "Related Allowance"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableRelatedAllowance",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance": {
     "auth_ref": [
      "r202"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.",
        "label": "Impaired Financing Receivable, Unpaid Principal Balance",
        "totalLabel": "Impaired Financing Receivable, Unpaid Principal Balance, Total"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableUnpaidPrincipalBalance",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalanceAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Impaired Financing Receivable, Unpaid Principal Balance [Abstract]",
        "terseLabel": "Impaired Financing Receivable, Unpaid Principal Balance [Abstract]"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableUnpaidPrincipalBalanceAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment": {
     "auth_ref": [
      "r203",
      "r206"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of average investment of impaired financing receivables for which there is no related allowance for credit losses.",
        "label": "Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment",
        "verboseLabel": "Average Recorded Investment, with no related allowance recorded"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod": {
     "auth_ref": [
      "r204"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest income, recognized on accrual basis, on financing receivables that are recognized as impaired, for which there is no related allowance for credit losses.",
        "label": "Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method",
        "terseLabel": "Interest Income Recognized, with no related allowance recorded"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment": {
     "auth_ref": [
      "r200"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_ImpairedFinancingReceivableRecordedInvestment",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.",
        "label": "Impaired Financing Receivable, with No Related Allowance, Recorded Investment",
        "terseLabel": "Recorded Investment, with no related allowance recorded"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance": {
     "auth_ref": [
      "r202"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of unpaid principal balance of impaired financing receivables for which there is no related allowance for credit losses.",
        "label": "Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance",
        "terseLabel": "Unpaid Principal Balance, with no related allowance recorded"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment": {
     "auth_ref": [
      "r203",
      "r206"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of average investment of impaired financing receivables for which there is a related allowance for credit losses.",
        "label": "Impaired Financing Receivable, with Related Allowance, Average Recorded Investment",
        "terseLabel": "Average Recorded Investment, with an allowance recorded"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod": {
     "auth_ref": [
      "r204"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest income, recognized on accrual basis, on financing receivables, for which there is a related allowance for credit losses and are recognized as impaired.",
        "label": "Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method",
        "terseLabel": "Interest Income Recognized, with an allowance recorded"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment": {
     "auth_ref": [
      "r200"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_ImpairedFinancingReceivableRecordedInvestment",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.",
        "label": "Impaired Financing Receivable, with Related Allowance, Recorded Investment",
        "terseLabel": "Recorded Investment, with an allowance recorded"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance": {
     "auth_ref": [
      "r202"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Unpaid principal balance of impaired financing receivables for which there is a related allowance for credit losses.",
        "label": "Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance",
        "terseLabel": "Unpaid Principal Balance, with an allowance recorded"
       }
      }
     },
     "localname": "ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ImpairedFinancingReceivablesTableTextBlock": {
     "auth_ref": [
      "r205"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of impaired financing receivables.",
        "label": "Impaired Financing Receivables [Table Text Block]",
        "terseLabel": "Impaired Financing Receivables"
       }
      }
     },
     "localname": "ImpairedFinancingReceivablesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ImpairmentOfInvestments": {
     "auth_ref": [
      "r226"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.",
        "label": "Other than Temporary Impairment Losses, Investments",
        "terseLabel": "Other than temporary impairment losses, investments"
       }
      }
     },
     "localname": "ImpairmentOfInvestments",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest": {
     "auth_ref": [
      "r62",
      "r159",
      "r171",
      "r175",
      "r178",
      "r181",
      "r647",
      "r664",
      "r682",
      "r715"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.",
        "label": "Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest",
        "totalLabel": "INCOME BEFORE PROVISION FOR INCOME TAXES"
       }
      }
     },
     "localname": "IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeStatementAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "CONSOLIDATED STATEMENTS OF INCOME"
       }
      }
     },
     "localname": "IncomeStatementAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeStatementLocationAxis": {
     "auth_ref": [
      "r327",
      "r329"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by location in the income statement.",
        "label": "Income Statement Location [Axis]"
       }
      }
     },
     "localname": "IncomeStatementLocationAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeStatementLocationDomain": {
     "auth_ref": [
      "r329"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Location in the income statement.",
        "label": "Income Statement Location [Domain]"
       }
      }
     },
     "localname": "IncomeStatementLocationDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_IncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r100",
      "r122",
      "r123",
      "r157",
      "r448",
      "r453",
      "r454",
      "r716"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.",
        "label": "Income Tax Expense (Benefit)",
        "negatedLabel": "(Provision) benefit for income taxes",
        "terseLabel": "PROVISION FOR INCOME TAXES"
       }
      }
     },
     "localname": "IncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxesPaid": {
     "auth_ref": [
      "r86",
      "r93"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income.",
        "label": "Income Taxes Paid",
        "terseLabel": "Income taxes"
       }
      }
     },
     "localname": "IncomeTaxesPaid",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet": {
     "auth_ref": [
      "r89"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 13.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in the amount due from borrowers for interest payments.",
        "label": "Increase (Decrease) in Accrued Interest Receivable, Net",
        "negatedTerseLabel": "Accrued interest receivable"
       }
      }
     },
     "localname": "IncreaseDecreaseInAccruedInterestReceivableNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInDepositOtherAssets": {
     "auth_ref": [
      "r89"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in moneys or securities given as security including, but not limited to, contract, escrow, or earnest money deposits, retainage (if applicable), deposits with clearing organizations and others, collateral, or margin deposits.",
        "label": "Increase (Decrease) in Deposit Assets",
        "negatedTerseLabel": "Net increase in deposits"
       }
      }
     },
     "localname": "IncreaseDecreaseInDepositOtherAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInOperatingAssetsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Increase (Decrease) in Operating Assets [Abstract]",
        "terseLabel": "Changes in operating assets and liabilities"
       }
      }
     },
     "localname": "IncreaseDecreaseInOperatingAssetsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncreaseDecreaseInOtherAccruedLiabilities": {
     "auth_ref": [
      "r89"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 15.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in other expenses incurred but not yet paid.",
        "label": "Increase (Decrease) in Other Accrued Liabilities",
        "terseLabel": "Other liabilities"
       }
      }
     },
     "localname": "IncreaseDecreaseInOtherAccruedLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInOtherCurrentAssets": {
     "auth_ref": [
      "r89"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 14.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in current assets classified as other.",
        "label": "Increase (Decrease) in Other Current Assets",
        "negatedTerseLabel": "Other assets"
       }
      }
     },
     "localname": "IncreaseDecreaseInOtherCurrentAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInStockholdersEquityRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Increase (Decrease) in Stockholders' Equity [Roll Forward]",
        "terseLabel": "Increase (Decrease) in Stockholders' Equity [Roll Forward]"
       }
      }
     },
     "localname": "IncreaseDecreaseInStockholdersEquityRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements": {
     "auth_ref": [
      "r128",
      "r129",
      "r130",
      "r136"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareEarningsPerShareBasicAndDilutesDetailsCalc": {
       "order": 2.0,
       "parentTag": "us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding",
       "weight": 1.0
      }
     },
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.",
        "label": "Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements",
        "terseLabel": "Dilutive shares (in shares)"
       }
      }
     },
     "localname": "IncrementalCommonSharesAttributableToShareBasedPaymentArrangements",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareScheduleOfEarningsPerShareBasicAndDilutedDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_InformationByCategoryOfDebtSecurityAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by category of debt security, either available-for-sale or held-to-maturity.",
        "label": "Debt Security Category [Axis]"
       }
      }
     },
     "localname": "InformationByCategoryOfDebtSecurityAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_InformationTechnologyAndDataProcessing": {
     "auth_ref": [
      "r69"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 3.0,
       "parentTag": "us-gaap_NoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of expenses incurred in the period for information technology and data processing products and services.",
        "label": "Information Technology and Data Processing",
        "terseLabel": "Data processing"
       }
      }
     },
     "localname": "InformationTechnologyAndDataProcessing",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestAndDividendIncomeOperating": {
     "auth_ref": [
      "r670"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_InterestIncomeExpenseNet",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the total of interest and dividend income, including any amortization and accretion (as applicable) of discounts and premiums, earned from (1) loans and leases whether held-for-sale or held-in-portfolio; (2) investment securities; (3) federal funds sold; (4) securities purchased under agreements to resell; (5) investments in banker's acceptances, commercial paper, or certificates of deposit; (6) dividend income; or (7) other investments not otherwise specified herein.",
        "label": "Interest and Dividend Income, Operating",
        "totalLabel": "Total interest and dividend income"
       }
      }
     },
     "localname": "InterestAndDividendIncomeOperating",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestAndFeeIncomeOtherLoans": {
     "auth_ref": [
      "r669"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_InterestAndDividendIncomeOperating",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest and fee income from loans classified as other.",
        "label": "Interest and Fee Income, Other Loans",
        "terseLabel": "Loans receivable, including fees"
       }
      }
     },
     "localname": "InterestAndFeeIncomeOtherLoans",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestBearingDepositLiabilities": {
     "auth_ref": [
      "r658"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_Deposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate of all domestic and foreign interest-bearing deposit liabilities.",
        "label": "Interest-bearing Deposit Liabilities",
        "terseLabel": "Interest-bearing accounts"
       }
      }
     },
     "localname": "InterestBearingDepositLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestBearingDepositsInBanks": {
     "auth_ref": [
      "r649",
      "r662"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_CashAndCashEquivalentsAtCarryingValue",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "For banks and other depository institutions (including Federal Reserve Banks, if applicable): Interest-bearing deposits in other financial institutions for relatively short periods of time including, for example, certificates of deposits, which are presented separately from cash on the balance sheet.",
        "label": "Interest-bearing Deposits in Banks and Other Financial Institutions",
        "terseLabel": "Interest-bearing deposits at other financial institutions"
       }
      }
     },
     "localname": "InterestBearingDepositsInBanks",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestBearingDomesticDepositBrokered": {
     "auth_ref": [
      "r658"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest-bearing domestic third-party deposits placed by or through the assistance of a deposit broker, also known as brokered deposit liabilities.",
        "label": "Interest-bearing Domestic Deposit, Brokered",
        "terseLabel": "Interest-bearing domestic deposit, brokered deposits"
       }
      }
     },
     "localname": "InterestBearingDomesticDepositBrokered",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestBearingDomesticDepositChecking": {
     "auth_ref": [
      "r658"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_Deposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest-bearing domestic checking deposit liabilities.",
        "label": "Interest-bearing Domestic Deposit, Checking",
        "terseLabel": "Interest-bearing checking"
       }
      }
     },
     "localname": "InterestBearingDomesticDepositChecking",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestExpense": {
     "auth_ref": [
      "r61",
      "r153",
      "r561",
      "r562",
      "r681"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_InterestIncomeExpenseNet",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of the cost of borrowed funds accounted for as interest expense.",
        "label": "Interest Expense",
        "totalLabel": "Total interest expense"
       }
      }
     },
     "localname": "InterestExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestExpenseAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Interest Expense [Abstract]",
        "terseLabel": "INTEREST EXPENSE"
       }
      }
     },
     "localname": "InterestExpenseAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_InterestExpenseDeposits": {
     "auth_ref": [
      "r679"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsInterestExpenseByDepositCategoryDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_InterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate amount of interest expense on all deposits.",
        "label": "Interest Expense, Deposits",
        "terseLabel": "Deposits",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "InterestExpenseDeposits",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsInterestExpenseByDepositCategoryDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestExpenseDomesticDepositLiabilitiesCertificatesOfDeposit": {
     "auth_ref": [
      "r679"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsInterestExpenseByDepositCategoryDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_InterestExpenseDeposits",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest expense on domestic certificates of deposit liabilities.",
        "label": "Interest Expense Domestic Deposit Liabilities, Certificates of Deposit",
        "terseLabel": "Certificates of deposit"
       }
      }
     },
     "localname": "InterestExpenseDomesticDepositLiabilitiesCertificatesOfDeposit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsInterestExpenseByDepositCategoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestExpenseDomesticDepositLiabilitiesChecking": {
     "auth_ref": [
      "r679"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsInterestExpenseByDepositCategoryDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_InterestExpenseDeposits",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest expense on domestic checking deposit liabilities.",
        "label": "Interest Expense Domestic Deposit Liabilities, Checking",
        "terseLabel": "Interest-bearing checking"
       }
      }
     },
     "localname": "InterestExpenseDomesticDepositLiabilitiesChecking",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsInterestExpenseByDepositCategoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesLongTerm": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_InterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Interest expense incurred during the reporting period on long-term borrowings associated with Federal Home Loan Bank and Federal Reserve Bank advances.",
        "label": "Interest Expense, Borrowings",
        "terseLabel": "Borrowings"
       }
      }
     },
     "localname": "InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesLongTerm",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestExpenseMember": {
     "auth_ref": [
      "r492"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Primary financial statement caption encompassing interest expense.",
        "label": "Interest Expense Deposits"
       }
      }
     },
     "localname": "InterestExpenseMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_InterestExpenseSavingsDeposits": {
     "auth_ref": [
      "r679",
      "r765",
      "r766"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsInterestExpenseByDepositCategoryDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_InterestExpenseDeposits",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Interest expense incurred on all savings account deposits.",
        "label": "Interest Expense, Savings Deposits",
        "terseLabel": "Savings and money market"
       }
      }
     },
     "localname": "InterestExpenseSavingsDeposits",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsInterestExpenseByDepositCategoryDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestExpenseSubordinatedNotesAndDebentures": {
     "auth_ref": [
      "r680"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 3.0,
       "parentTag": "us-gaap_InterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Interest expense incurred during the reporting period on subordinated notes and debentures. Includes amortization of expenses incurred in the issuance of subordinated notes and debentures.",
        "label": "Interest Expense, Subordinated Notes and Debentures",
        "terseLabel": "Subordinated notes"
       }
      }
     },
     "localname": "InterestExpenseSubordinatedNotesAndDebentures",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss": {
     "auth_ref": [
      "r673"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of interest income or expense, including any amortization and accretion (as applicable) of discounts and premiums, including consideration of the provisions for loan, lease, credit, and other related losses.",
        "label": "Interest Income (Expense), after Provision for Loan Loss",
        "totalLabel": "NET INTEREST INCOME AFTER PROVISION FOR CREDIT LOSSES"
       }
      }
     },
     "localname": "InterestIncomeExpenseAfterProvisionForLoanLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestIncomeExpenseNet": {
     "auth_ref": [
      "r671"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
       "weight": 1.0
      },
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The net amount of operating interest income (expense).",
        "label": "Interest Income (Expense), Net",
        "totalLabel": "NET INTEREST INCOME",
        "verboseLabel": "Net interest income"
       }
      }
     },
     "localname": "InterestIncomeExpenseNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestIncomeMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Primary financial statement caption in which reported facts about interest income have been included.",
        "label": "Interest Income Securities"
       }
      }
     },
     "localname": "InterestIncomeMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_InterestPaidNet": {
     "auth_ref": [
      "r80",
      "r85",
      "r93"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash paid for interest, excluding capitalized interest, classified as operating activity. Includes, but is not limited to, payment to settle zero-coupon bond for accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount.",
        "label": "Interest Paid, Net",
        "terseLabel": "Interest on deposits and borrowings"
       }
      }
     },
     "localname": "InterestPaidNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet": {
     "auth_ref": [
      "r508"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The estimated net amount of unrealized gains or losses on interest rate cash flow hedges as of the balance sheet date expected to be reclassified to earnings within the next twelve months.",
        "label": "Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net",
        "terseLabel": "Reclassification to interest expense related to cash flow hedges over next 12 months"
       }
      }
     },
     "localname": "InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestRateDerivativeAssetsAtFairValue": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value as of the balance sheet date of interest rate derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets.",
        "label": "Interest Rate Derivative Assets, at Fair Value",
        "verboseLabel": "Fair Value, Asset"
       }
      }
     },
     "localname": "InterestRateDerivativeAssetsAtFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestRateDerivativeLiabilitiesAtFairValue": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities.",
        "label": "Interest Rate Derivative Liabilities, at Fair Value",
        "verboseLabel": "Fair Value, Liability"
       }
      }
     },
     "localname": "InterestRateDerivativeLiabilitiesAtFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestRateLockCommitmentsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Commitments to extend credit where the interest rate is locked in advance of funds being disbursed for a specified period of time.",
        "label": "Interest rate lock commitments with customers"
       }
      }
     },
     "localname": "InterestRateLockCommitmentsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueLevel3OnRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_InterestRateSwapMember": {
     "auth_ref": [
      "r491"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Forward based contracts in which two parties agree to swap periodic payments that are fixed at the outset of the swap contract with variable payments based on a market interest rate (index rate) over a specified period.",
        "label": "Interest rate swaps"
       }
      }
     },
     "localname": "InterestRateSwapMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeAssetsDetails",
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeLiabilitiesDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_InterestReceivable": {
     "auth_ref": [
      "r28"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 9.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.",
        "label": "Interest Receivable",
        "verboseLabel": "Accrued interest receivable"
       }
      }
     },
     "localname": "InterestReceivable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestsContinuedToBeHeldByTransferorFairValue": {
     "auth_ref": [
      "r595"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The carrying amount (fair value) as of the balance sheet date of the transferor's interests in transferred financial assets (typically securitized receivables, generally not involved in the collection of principal) following transfer of significant portions of such financial instruments to other parties. Such interests could be ancillary cash flows and interest-only strips.",
        "label": "Transferor's Interests in Transferred Financial Assets, Fair Value",
        "terseLabel": "Aggregate portfolio principal balance"
       }
      }
     },
     "localname": "InterestsContinuedToBeHeldByTransferorFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InternalCreditAssessmentAxis": {
     "auth_ref": [
      "r207",
      "r292",
      "r300",
      "r301",
      "r347",
      "r497"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by entity-defined rating.",
        "label": "Internal Credit Assessment [Axis]"
       }
      }
     },
     "localname": "InternalCreditAssessmentAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_InternalCreditAssessmentDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Entity defined credit risk rating.",
        "label": "Internal Credit Assessment [Domain]"
       }
      }
     },
     "localname": "InternalCreditAssessmentDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_InvestmentInFederalHomeLoanBankStockFairValueDisclosure": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of investments in Federal Home Loan Bank (FHLBank) stock.",
        "label": "Investment in Federal Home Loan Bank Stock, Fair Value Disclosure",
        "terseLabel": "FHLB stock, at cost"
       }
      }
     },
     "localname": "InvestmentInFederalHomeLoanBankStockFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InvestmentIncomeInterestAndDividend": {
     "auth_ref": [
      "r70"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_InterestAndDividendIncomeOperating",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount before accretion (amortization) of purchase discount (premium) of interest income and dividend income on nonoperating securities.",
        "label": "Investment Income, Interest and Dividend",
        "terseLabel": "Interest and dividends on investment securities, cash and cash equivalents, and certificates of deposit at other financial institutions"
       }
      }
     },
     "localname": "InvestmentIncomeInterestAndDividend",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of maturities of an entity's investments as well as any other information pertinent to the investments.",
        "label": "Investments Classified by Contractual Maturity Date [Table Text Block]",
        "terseLabel": "Schedule of Available-for-Sale and Held-To-Maturity Securities by Contractual Maturity"
       }
      }
     },
     "localname": "InvestmentsClassifiedByContractualMaturityDateTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "INVESTMENTS"
       }
      }
     },
     "localname": "InvestmentsDebtAndEquitySecuritiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock": {
     "auth_ref": [
      "r263",
      "r648",
      "r690",
      "r742",
      "r772"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for  investments in certain debt and equity securities.",
        "label": "Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]",
        "verboseLabel": "INVESTMENTS"
       }
      }
     },
     "localname": "InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestments"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LaborAndRelatedExpense": {
     "auth_ref": [
      "r67"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_NoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of expense for salary, wage, profit sharing; incentive and equity-based compensation; and other employee benefit.",
        "label": "Labor and Related Expense",
        "terseLabel": "Salaries and benefits"
       }
      }
     },
     "localname": "LaborAndRelatedExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LeaseCost": {
     "auth_ref": [
      "r574",
      "r576"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLeasesComponentsOfLeaseCostAndSupplementalInformationRelatedToOperatingLeasesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lease cost recognized by lessee for lease contract.",
        "label": "Lease, Cost",
        "totalLabel": "Total lease cost"
       }
      }
     },
     "localname": "LeaseCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesComponentsOfLeaseCostAndSupplementalInformationRelatedToOperatingLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LeaseCostAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Lease, Cost [Abstract]",
        "terseLabel": "Lease cost:"
       }
      }
     },
     "localname": "LeaseCostAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesComponentsOfLeaseCostAndSupplementalInformationRelatedToOperatingLeasesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LeaseCostTableTextBlock": {
     "auth_ref": [
      "r574"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of lessee's lease cost. Includes, but is not limited to, interest expense for finance lease, amortization of right-of-use asset for finance lease, operating lease cost, short-term lease cost, variable lease cost and sublease income.",
        "label": "Lease, Cost [Table Text Block]",
        "terseLabel": "Summary of lease cost"
       }
      }
     },
     "localname": "LeaseCostTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LeasesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "LEASES"
       }
      }
     },
     "localname": "LeasesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_LesseeLeaseDescriptionLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Lessee, Lease, Description [Line Items]"
       }
      }
     },
     "localname": "LesseeLeaseDescriptionLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LesseeLeaseDescriptionTable": {
     "auth_ref": [
      "r568"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about lessee's leases.",
        "label": "Lessee, Lease, Description [Table]"
       }
      }
     },
     "localname": "LesseeLeaseDescriptionTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LesseeOperatingLeaseExistenceOfOptionToExtend": {
     "auth_ref": [
      "r567"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicates (true false) whether lessee has option to extend operating lease.",
        "label": "Lessee, Operating Lease, Existence of Option to Extend [true false]",
        "terseLabel": "Options to extend"
       }
      }
     },
     "localname": "LesseeOperatingLeaseExistenceOfOptionToExtend",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesDetails"
     ],
     "xbrltype": "booleanItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock": {
     "auth_ref": [
      "r575"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of undiscounted cash flows of lessee's operating lease liability. Includes, but is not limited to, reconciliation of undiscounted cash flows to operating lease liability recognized in statement of financial position.",
        "label": "Lessee, Operating Lease, Liability, Maturity [Table Text Block]",
        "terseLabel": "Summary of maturities of operating lease liabilities"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityMaturityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue": {
     "auth_ref": [
      "r575"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetailscalc2": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease.",
        "label": "Lessee, Operating Lease, Liability, Payments, Due",
        "totalLabel": "Total lease payments"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths": {
     "auth_ref": [
      "r575"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Operating Leases, Future Minimum Payments Due, Next Twelve Months",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour": {
     "auth_ref": [
      "r575"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Lessee, Operating Lease, Liability, Payments, Due Year Four",
        "terseLabel": "2026"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearFour",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree": {
     "auth_ref": [
      "r575"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Lessee, Operating Lease, Liability, Payments, Due Year Three",
        "terseLabel": "2025"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearThree",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo": {
     "auth_ref": [
      "r575"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Lessee, Operating Lease, Liability, Payments, Due Year Two",
        "terseLabel": "2024"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearTwo",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear": {
     "auth_ref": [
      "r575"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease having initial or remaining lease term in excess of one year to be paid in remainder of current fiscal year.",
        "label": "Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount": {
     "auth_ref": [
      "r575"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetailscalc2": {
       "order": 1.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating lease.",
        "label": "Lessee, Operating Lease, Liability, Undiscounted Excess Amount",
        "negatedLabel": "Less imputed interest"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityUndiscountedExcessAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseRenewalTerm": {
     "auth_ref": [
      "r567"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.",
        "label": "Lessee Leasing Arrangements, Operating Leases, Renewal Term",
        "verboseLabel": "Renewal term"
       }
      }
     },
     "localname": "LesseeOperatingLeaseRenewalTerm",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_LesseeOperatingLeaseTermOfContract": {
     "auth_ref": [
      "r567"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.",
        "label": "Lessee, Operating Lease, Term of Contract",
        "verboseLabel": "Remaining lease terms"
       }
      }
     },
     "localname": "LesseeOperatingLeaseTermOfContract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_LesseeOperatingLeasesTextBlock": {
     "auth_ref": [
      "r577"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for operating leases of lessee. Includes, but is not limited to, description of operating lease and maturity analysis of operating lease liability.",
        "label": "Lessee, Operating Leases [Text Block]",
        "terseLabel": "LEASES"
       }
      }
     },
     "localname": "LesseeOperatingLeasesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeases"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_Liabilities": {
     "auth_ref": [
      "r23",
      "r99",
      "r173",
      "r267",
      "r350",
      "r351",
      "r352",
      "r354",
      "r355",
      "r356",
      "r357",
      "r358",
      "r359",
      "r360",
      "r460",
      "r465",
      "r466",
      "r544",
      "r581",
      "r582"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.",
        "label": "Liabilities",
        "totalLabel": "Total liabilities"
       }
      }
     },
     "localname": "Liabilities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Liabilities [Abstract]",
        "terseLabel": "LIABILITIES"
       }
      }
     },
     "localname": "LiabilitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LiabilitiesAndStockholdersEquity": {
     "auth_ref": [
      "r20",
      "r99",
      "r267",
      "r544",
      "r583",
      "r654",
      "r708"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of liabilities and equity items, including the portion of equity attributable to noncontrolling interests, if any.",
        "label": "Liabilities and Equity",
        "totalLabel": "TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY"
       }
      }
     },
     "localname": "LiabilitiesAndStockholdersEquity",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesCurrentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Liabilities, Current [Abstract]",
        "terseLabel": "Liabilities"
       }
      }
     },
     "localname": "LiabilitiesCurrentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LoanCommitmentsPolicy": {
     "auth_ref": [
      "r502",
      "r503"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy for loan commitments accounted for as derivatives, including the methods and assumptions used to estimate fair value and any associated hedging strategies.",
        "label": "Loan Commitments, Policy [Policy Text Block]",
        "terseLabel": "Loan Commitments"
       }
      }
     },
     "localname": "LoanCommitmentsPolicy",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LoanProcessingFee": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 5.0,
       "parentTag": "us-gaap_NoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Expenses paid for obtaining loans which includes expenses such as application and origination fees.",
        "label": "Loan Processing Fee",
        "terseLabel": "Loan costs"
       }
      }
     },
     "localname": "LoanProcessingFee",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LoansAndLeasesReceivableAllowance": {
     "auth_ref": [
      "r193",
      "r197",
      "r216",
      "r223"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_NotesReceivableNet",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.",
        "label": "Loans and Leases Receivable, Allowance",
        "negatedTerseLabel": "Allowance for credit losses on loans",
        "terseLabel": "Allowance for credit losses on loans"
       }
      }
     },
     "localname": "LoansAndLeasesReceivableAllowance",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LoansAndLeasesReceivableGrossCarryingAmount": {
     "auth_ref": [
      "r190"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_NotesReceivableNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.",
        "label": "Loans and Leases Receivable, Gross",
        "netLabel": "Total loans receivable",
        "terseLabel": "Loans receivable, gross",
        "totalLabel": "Total loans receivable",
        "verboseLabel": "Total loans receivable, gross"
       }
      }
     },
     "localname": "LoansAndLeasesReceivableGrossCarryingAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LoansAndLeasesReceivableNetReportedAmountAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Loans Receivable, Net [Abstract]",
        "terseLabel": "LOANS RECEIVABLE"
       }
      }
     },
     "localname": "LoansAndLeasesReceivableNetReportedAmountAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LoansAndLeasesReceivablePastDueStatusPolicy": {
     "auth_ref": [
      "r211"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of the accounting policy for past due status of loans and leases receivable.",
        "label": "Loans and Leases Receivable, Past Due Status, Policy [Policy Text Block]",
        "terseLabel": "Nonaccrual and Past Due Loans"
       }
      }
     },
     "localname": "LoansAndLeasesReceivablePastDueStatusPolicy",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LoansHeldForSaleFairValueDisclosure": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 7.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.",
        "label": "Loans Held-for-sale, Fair Value Disclosure",
        "terseLabel": "Loans held for sale, at fair value"
       }
      }
     },
     "localname": "LoansHeldForSaleFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LoansReceivableFairValueDisclosure": {
     "auth_ref": [
      "r217"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.",
        "label": "Loans Receivable, Fair Value Disclosure",
        "verboseLabel": "Loans receivable, at fair value"
       }
      }
     },
     "localname": "LoansReceivableFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LossContingenciesByNatureOfContingencyAxis": {
     "auth_ref": [
      "r335",
      "r336",
      "r337",
      "r339",
      "r340",
      "r341",
      "r342",
      "r345",
      "r346"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of existing condition, situation, or set of circumstances involving uncertainty as to possible loss to an enterprise that will ultimately be resolved when one or more future events occur or fail to occur.",
        "label": "Loss Contingency Nature [Axis]"
       }
      }
     },
     "localname": "LossContingenciesByNatureOfContingencyAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LossContingenciesLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Loss Contingencies [Line Items]",
        "terseLabel": "Loss Contingencies [Line Items]"
       }
      }
     },
     "localname": "LossContingenciesLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LossContingenciesTable": {
     "auth_ref": [
      "r335",
      "r336",
      "r337",
      "r339",
      "r340",
      "r341",
      "r342",
      "r345",
      "r346"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Discloses the specific components (such as the nature, name, and date) of the loss contingency and gives an estimate of the possible loss or range of loss, or states that a reasonable estimate cannot be made. Excludes environmental contingencies, warranties and unconditional purchase obligations.",
        "label": "Loss Contingencies [Table]",
        "terseLabel": "Loss Contingencies [Table]"
       }
      }
     },
     "localname": "LossContingenciesTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LossContingencyAccrualAtCarryingValue": {
     "auth_ref": [
      "r335"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of loss contingency liability.",
        "label": "Loss Contingency Accrual",
        "terseLabel": "Reserve for estimated losses"
       }
      }
     },
     "localname": "LossContingencyAccrualAtCarryingValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LossContingencyNatureDomain": {
     "auth_ref": [
      "r335",
      "r336",
      "r337",
      "r339",
      "r340",
      "r341",
      "r342",
      "r345",
      "r346"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "An existing condition, situation, or set of circumstances involving uncertainty as to possible loss to an enterprise that will ultimately be resolved when one or more future events occur or fail to occur. Resolution of the uncertainty may confirm the incurrence of a loss or impairment of an asset or the incurrence of a liability.",
        "label": "Loss Contingency, Nature [Domain]"
       }
      }
     },
     "localname": "LossContingencyNatureDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LossContingencyPendingClaimsNumber": {
     "auth_ref": [
      "r338"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of pending claims pertaining to a loss contingency.",
        "label": "Loss Contingency, Pending Claims, Number",
        "terseLabel": "Pending material legal actions"
       }
      }
     },
     "localname": "LossContingencyPendingClaimsNumber",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "us-gaap_MarketingAndAdvertisingExpense": {
     "auth_ref": [
      "r68"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 6.0,
       "parentTag": "us-gaap_NoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The total expense recognized in the period for promotion, public relations, and brand or product advertising.",
        "label": "Marketing and Advertising Expense",
        "terseLabel": "Marketing and advertising"
       }
      }
     },
     "localname": "MarketingAndAdvertisingExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_MortgageBackedSecuritiesMember": {
     "auth_ref": [
      "r227",
      "r390",
      "r391",
      "r397",
      "r735"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Securities collateralized by mortgage loans.",
        "label": "Mortgage-backed securities"
       }
      }
     },
     "localname": "MortgageBackedSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_MortgageBackedSecuritiesOtherMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Securities collateralized by other mortgage loans.",
        "label": "Forward TBA mortgage-backed securities"
       }
      }
     },
     "localname": "MortgageBackedSecuritiesOtherMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_MortgageLoansInProcessOfForeclosureAmount": {
     "auth_ref": [
      "r209"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.",
        "label": "Mortgage Loans in Process of Foreclosure, Amount",
        "terseLabel": "Mortgage loans in process of foreclosure"
       }
      }
     },
     "localname": "MortgageLoansInProcessOfForeclosureAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureOtherRealEstateOwnedOreoNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_MortgageServicingRightsMSRImpairmentRecovery": {
     "auth_ref": [
      "r90",
      "r631"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 11.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      },
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 11.0,
       "parentTag": "us-gaap_NoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The adjustment to the carrying value of the rights retained or purchased to service mortgages. These adjustments are made when the estimate of the fair value is changed. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.",
        "label": "Mortgage Servicing Rights (MSR) Impairment (Recovery)",
        "terseLabel": "Impairment (recovery) of servicing rights",
        "verboseLabel": "Recovery of servicing rights"
       }
      }
     },
     "localname": "MortgageServicingRightsMSRImpairmentRecovery",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_MortgagesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A loan to finance the purchase of real estate where the lender has a lien on the property as collateral for the loan.",
        "label": "REAL ESTATE LOANS."
       }
      }
     },
     "localname": "MortgagesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_MunicipalBondsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long-term debt securities issued by state, city or local governments or the agencies operated by state, city or local governments.",
        "label": "Municipal bonds"
       }
      }
     },
     "localname": "MunicipalBondsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsDiscountRateDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_NetCashProvidedByUsedInFinancingActivities": {
     "auth_ref": [
      "r84"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.",
        "label": "Net Cash Provided by (Used in) Financing Activities",
        "totalLabel": "Net cash from financing activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInFinancingActivities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Net Cash Provided by (Used in) Financing Activities [Abstract]",
        "terseLabel": "CASH FLOWS FROM FINANCING ACTIVITIES"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInFinancingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetCashProvidedByUsedInInvestingActivities": {
     "auth_ref": [
      "r84"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash inflow (outflow) from investing activities, including discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.",
        "label": "Net Cash Provided by (Used in) Investing Activities",
        "totalLabel": "Net cash used by investing activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInInvestingActivities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Net Cash Provided by (Used in) Investing Activities [Abstract]",
        "terseLabel": "CASH FLOWS USED BY INVESTING ACTIVITIES"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInInvestingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetCashProvidedByUsedInOperatingActivities": {
     "auth_ref": [
      "r84",
      "r88",
      "r91"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect",
       "weight": 1.0
      }
     },
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.",
        "label": "Net Cash Provided by (Used in) Operating Activities",
        "totalLabel": "Net cash from operating activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInOperatingActivities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Net Cash Provided by (Used in) Operating Activities [Abstract]",
        "terseLabel": "CASH FLOWS FROM OPERATING ACTIVITIES"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInOperatingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetIncomeLoss": {
     "auth_ref": [
      "r6",
      "r51",
      "r54",
      "r59",
      "r63",
      "r91",
      "r99",
      "r109",
      "r114",
      "r115",
      "r117",
      "r118",
      "r122",
      "r123",
      "r131",
      "r159",
      "r171",
      "r175",
      "r178",
      "r181",
      "r267",
      "r350",
      "r351",
      "r352",
      "r354",
      "r355",
      "r356",
      "r357",
      "r358",
      "r359",
      "r360",
      "r520",
      "r544",
      "r665",
      "r711"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareEarningsPerShareBasicAndDilutesDetailsCalc": {
       "order": 1.0,
       "parentTag": "us-gaap_UndistributedEarningsLossAvailableToCommonShareholdersBasic",
       "weight": 1.0
      },
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_ComprehensiveIncomeNetOfTax",
       "weight": 1.0
      },
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.",
        "label": "Net Income (Loss) Attributable to Parent",
        "terseLabel": "Net Income",
        "totalLabel": "NET INCOME",
        "verboseLabel": "Net income"
       }
      }
     },
     "localname": "NetIncomeLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails",
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareScheduleOfEarningsPerShareBasicAndDilutedDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy pertaining to new accounting pronouncements that may impact the entity's financial reporting. Includes, but is not limited to, quantification of the expected or actual impact.",
        "label": "New Accounting Pronouncements, Policy [Policy Text Block]",
        "terseLabel": "RECENT ACCOUNTING PRONOUNCEMENTS"
       }
      }
     },
     "localname": "NewAccountingPronouncementsPolicyPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_NoncashInvestingAndFinancingItemsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Noncash Investing and Financing Items [Abstract]",
        "terseLabel": "SUPPLEMENTARY DISCLOSURES OF NONCASH OPERATING, INVESTING AND FINANCING ACTIVITIES"
       }
      }
     },
     "localname": "NoncashInvestingAndFinancingItemsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NondesignatedMember": {
     "auth_ref": [
      "r477"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Derivative instrument not designated as hedging instrument under Generally Accepted Accounting Principles (GAAP).",
        "label": "Not Designated as Hedging Instrument"
       }
      }
     },
     "localname": "NondesignatedMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesDerivativeInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_NoninterestBearingDepositLiabilities": {
     "auth_ref": [
      "r658"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_Deposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate amount of all domestic and foreign noninterest-bearing deposits liabilities held by the entity.",
        "label": "Noninterest-bearing Deposit Liabilities",
        "terseLabel": "Noninterest-bearing accounts"
       }
      }
     },
     "localname": "NoninterestBearingDepositLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesErrorCorrectionsDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NoninterestBearingDomesticDepositChecking": {
     "auth_ref": [
      "r658"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_Deposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of noninterest-bearing domestic checking deposit liabilities.",
        "label": "Noninterest-bearing Domestic Deposit, Checking",
        "terseLabel": "Noninterest-bearing checking"
       }
      }
     },
     "localname": "NoninterestBearingDomesticDepositChecking",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NoninterestExpense": {
     "auth_ref": [
      "r678"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
       "weight": -1.0
      },
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 3.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total aggregate amount of all noninterest expense.",
        "label": "Noninterest Expense",
        "negatedTerseLabel": "Noninterest expense",
        "totalLabel": "Total noninterest expense"
       }
      }
     },
     "localname": "NoninterestExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NoninterestExpenseAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Noninterest Expense [Abstract]",
        "terseLabel": "NONINTEREST EXPENSE"
       }
      }
     },
     "localname": "NoninterestExpenseAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NoninterestIncome": {
     "auth_ref": [
      "r675"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
       "weight": 1.0
      },
      "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomersDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The total amount of noninterest income which may be derived from: (1) fees and commissions; (2) premiums earned; (3) insurance policy charges; (4) the sale or disposal of assets; and (5) other sources not otherwise specified.",
        "label": "Noninterest Income",
        "terseLabel": "Noninterest income",
        "totalLabel": "Total noninterest income"
       }
      }
     },
     "localname": "NoninterestIncome",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails",
      "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomersDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NoninterestIncomeAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Noninterest Income [Abstract]",
        "terseLabel": "NONINTEREST INCOME",
        "verboseLabel": "Noninterest Income"
       }
      }
     },
     "localname": "NoninterestIncomeAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomersDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NoninterestIncomeOther": {
     "auth_ref": [
      "r675"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 4.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Represents the total of noninterest income derived from certain activities and assets including (for example): (1) venture capital investments; (2) bank owned life insurance; (3) foreign currency transactions; and (4) mortgage servicing rights.",
        "label": "Noninterest Income, Other",
        "terseLabel": "Other noninterest income"
       }
      }
     },
     "localname": "NoninterestIncomeOther",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NotesReceivableNet": {
     "auth_ref": [
      "r14",
      "r190",
      "r291"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 8.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement.",
        "label": "Financing Receivable, Net",
        "terseLabel": "Loans receivable, net (includes $14,863 and $16,083, at fair value, respectively)",
        "totalLabel": "Total loans receivable, net"
       }
      }
     },
     "localname": "NotesReceivableNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NumberOfOperatingSegments": {
     "auth_ref": [
      "r147"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.",
        "label": "Number of Operating Segments",
        "terseLabel": "Number of operating segments"
       }
      }
     },
     "localname": "NumberOfOperatingSegments",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesDetails",
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "us-gaap_NumberOfRealEstateProperties": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The number of real estate properties owned as of the balance sheet date.",
        "label": "Number of Real Estate Properties",
        "verboseLabel": "Number of OREO Properties"
       }
      }
     },
     "localname": "NumberOfRealEstateProperties",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureOtherRealEstateOwnedOreoNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "us-gaap_NumberOfUnitsInRealEstateProperty": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The number of units in a real estate property owned as of the balance sheet date.",
        "label": "Number of Units in Real Estate Property"
       }
      }
     },
     "localname": "NumberOfUnitsInRealEstateProperty",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "us-gaap_OccupancyNet": {
     "auth_ref": [
      "r69",
      "r563",
      "r676"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 7.0,
       "parentTag": "us-gaap_NoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of net occupancy expense that may include items, such as depreciation of facilities and equipment, lease expenses, property taxes and property and casualty insurance expense.",
        "label": "Occupancy, Net",
        "terseLabel": "Occupancy"
       }
      }
     },
     "localname": "OccupancyNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OffsettingAssetsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Offsetting Assets [Line Items]"
       }
      }
     },
     "localname": "OffsettingAssetsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OffsettingAssetsTable": {
     "auth_ref": [
      "r33",
      "r34"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about derivative and financial assets that are subject to offsetting, including enforceable master netting arrangements.",
        "label": "Offsetting Assets [Table]"
       }
      }
     },
     "localname": "OffsettingAssetsTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OffsettingAssetsTableTextBlock": {
     "auth_ref": [
      "r33",
      "r34"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of derivative and other financial assets that are subject to offsetting, including master netting arrangements.",
        "label": "Offsetting Assets [Table Text Block]",
        "terseLabel": "Schedule of offsetting derivative assets"
       }
      }
     },
     "localname": "OffsettingAssetsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_OffsettingLiabilitiesLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Offsetting Liabilities [Line Items]"
       }
      }
     },
     "localname": "OffsettingLiabilitiesLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeLiabilitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OffsettingLiabilitiesTable": {
     "auth_ref": [
      "r33",
      "r34"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about derivative and financial liabilities that are subject to offsetting, including enforceable master netting arrangements.",
        "label": "Offsetting Liabilities [Table]"
       }
      }
     },
     "localname": "OffsettingLiabilitiesTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesOffsettingDerivativeLiabilitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OffsettingLiabilitiesTableTextBlock": {
     "auth_ref": [
      "r33",
      "r34"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of derivative and other financial liabilities that are subject to offsetting, including master netting arrangements.",
        "label": "Offsetting Liabilities [Table Text Block]",
        "terseLabel": "Schedule of offsetting derivative liabilities"
       }
      }
     },
     "localname": "OffsettingLiabilitiesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_OperatingLeaseCost": {
     "auth_ref": [
      "r569",
      "r576"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLeasesComponentsOfLeaseCostAndSupplementalInformationRelatedToOperatingLeasesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_LeaseCost",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.",
        "label": "Operating Lease, Cost",
        "terseLabel": "Operating lease cost"
       }
      }
     },
     "localname": "OperatingLeaseCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesComponentsOfLeaseCostAndSupplementalInformationRelatedToOperatingLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Operating Lease Liabilities, Payments Due [Abstract]",
        "terseLabel": "Maturities of operating lease liabilities"
       }
      }
     },
     "localname": "OperatingLeaseLiabilitiesPaymentsDueAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OperatingLeaseLiability": {
     "auth_ref": [
      "r565"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetailscalc2": {
       "order": 2.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      },
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Present value of lessee's discounted obligation for lease payments from operating lease.",
        "label": "Operating Lease, Liability",
        "netLabel": "Total",
        "verboseLabel": "Operating lease liabilities"
       }
      }
     },
     "localname": "OperatingLeaseLiability",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasePayments": {
     "auth_ref": [
      "r566",
      "r571"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.",
        "label": "Operating Lease, Payments",
        "terseLabel": "Operating cash flows from operating leases"
       }
      }
     },
     "localname": "OperatingLeasePayments",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesComponentsOfLeaseCostAndSupplementalInformationRelatedToOperatingLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseRightOfUseAsset": {
     "auth_ref": [
      "r564"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 11.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's right to use underlying asset under operating lease.",
        "label": "Operating Lease, Right-of-Use Asset",
        "verboseLabel": "Operating lease right-of-use (\"ROU\") assets"
       }
      }
     },
     "localname": "OperatingLeaseRightOfUseAsset",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent": {
     "auth_ref": [
      "r573",
      "r576"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average discount rate for operating lease calculated at point in time.",
        "label": "Operating Lease, Weighted Average Discount Rate, Percent",
        "terseLabel": "Weighted average discount rate- operating leases"
       }
      }
     },
     "localname": "OperatingLeaseWeightedAverageDiscountRatePercent",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesComponentsOfLeaseCostAndSupplementalInformationRelatedToOperatingLeasesDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1": {
     "auth_ref": [
      "r572",
      "r576"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.",
        "label": "Operating Lease, Weighted Average Remaining Lease Term",
        "terseLabel": "Weighted average remaining lease term- operating leases"
       }
      }
     },
     "localname": "OperatingLeaseWeightedAverageRemainingLeaseTerm1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesComponentsOfLeaseCostAndSupplementalInformationRelatedToOperatingLeasesDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_OtherAggregatedInvestmentsMember": {
     "auth_ref": [
      "r739",
      "r740",
      "r741"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Other investments in debt and equity securities and other forms of securities that provide ownership interests.",
        "label": "U.S. Small Business Administration securities"
       }
      }
     },
     "localname": "OtherAggregatedInvestmentsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_OtherAssets": {
     "auth_ref": [
      "r10",
      "r652",
      "r704"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 15.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of assets classified as other.",
        "label": "Other Assets",
        "verboseLabel": "Other assets"
       }
      }
     },
     "localname": "OtherAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherBorrowings": {
     "auth_ref": [
      "r659"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The carrying amount as of the balance sheet date for the aggregate of other miscellaneous borrowings owed by the reporting entity.",
        "label": "Other Borrowings",
        "terseLabel": "Borrowings"
       }
      }
     },
     "localname": "OtherBorrowings",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Other Comprehensive Income Cash Flow Hedges [Abstract]",
        "terseLabel": "Derivative financial instruments:"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax": {
     "auth_ref": [
      "r42",
      "r46",
      "r481",
      "r486",
      "r505"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome": {
       "order": 3.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before tax and reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness.",
        "label": "Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax",
        "terseLabel": "Unrealized derivative gain (loss) during period"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax": {
     "auth_ref": [
      "r47"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome": {
       "order": 5.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before reclassification, of tax expense (benefit) for gain (loss) from derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.",
        "label": "Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax",
        "negatedLabel": "Income tax (provision) benefit related to unrealized derivative gain"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax": {
     "auth_ref": [
      "r46",
      "r50",
      "r487"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome": {
       "order": 4.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before tax, of reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.",
        "label": "Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax",
        "negatedLabel": "Reclassification adjustment for realized (gain) loss, net included in net income",
        "terseLabel": "Realized gains (losses) (pre-tax) reclassified from AOCI into net income"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesEffectOfFairValueAndCashFlowHedgeAccountingDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax": {
     "auth_ref": [
      "r47"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome": {
       "order": 6.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of tax expense (benefit) for reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.",
        "label": "Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax",
        "terseLabel": "Income tax provision (benefit) related to reclassification, net"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossNetOfTax": {
     "auth_ref": [
      "r52",
      "r55",
      "r57",
      "r58",
      "r60",
      "r64",
      "r371",
      "r554",
      "r559",
      "r560",
      "r666",
      "r712"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_ComprehensiveIncomeNetOfTax",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after tax and reclassification adjustments of other comprehensive income (loss).",
        "label": "Other Comprehensive Income (Loss), Net of Tax",
        "netLabel": "Other comprehensive loss, net of tax",
        "totalLabel": "Other comprehensive loss, net of tax"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]",
        "terseLabel": "Other comprehensive loss:"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax": {
     "auth_ref": [
      "r43",
      "r46",
      "r262"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before tax and adjustment, of unrealized holding gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Excludes unrealized gain (loss) on investment in debt security measured at amortized cost (held-to-maturity) from transfer to available-for-sale.",
        "label": "Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax",
        "terseLabel": "Unrealized loss during period"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax": {
     "auth_ref": [
      "r44",
      "r47"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before adjustment, of tax expense (benefit) for unrealized holding gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Excludes tax expense (benefit) for unrealized gain (loss) on investment in debt security measured at amortized cost (held-to-maturity) from transfer to available-for-sale.",
        "label": "Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax",
        "negatedTerseLabel": "Income tax benefit related to unrealized holding loss"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfComprehensiveLossIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherLiabilities": {
     "auth_ref": [
      "r660"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 6.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of liabilities classified as other.",
        "label": "Other Liabilities",
        "terseLabel": "Other liabilities"
       }
      }
     },
     "localname": "OtherLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherRealEstateAndForeclosedAssets": {
     "auth_ref": [
      "r657"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Carrying amount as of the balance sheet date of other real estate and foreclosed assets. Other real estate may include real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. Foreclosed assets include all assets obtained in full or partial satisfaction of a debt arrangement through foreclosure proceedings.",
        "label": "Other Real Estate, Foreclosed Assets, and Repossessed Assets",
        "periodEndLabel": "Ending balance",
        "periodStartLabel": "Beginning balance"
       }
      }
     },
     "localname": "OtherRealEstateAndForeclosedAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureOtherRealEstateOwnedOreoActivityRelatedToOreoDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherRealEstatePeriodIncreaseDecrease": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Change in carrying amount of other real estate not separately disclosed. The change includes for example, but is not limited to, additions, improvements, disposals and valuation adjustments.",
        "label": "Other Real Estate, Period Increase (Decrease)",
        "verboseLabel": "Loss on sale of OREO"
       }
      }
     },
     "localname": "OtherRealEstatePeriodIncreaseDecrease",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureOtherRealEstateOwnedOreoActivityRelatedToOreoDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherRealEstateRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Other Real Estate [Roll Forward]",
        "terseLabel": "Other Real Estate [Roll Forward]"
       }
      }
     },
     "localname": "OtherRealEstateRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureOtherRealEstateOwnedOreoActivityRelatedToOreoDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OtherRealEstateRollForwardTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the change in other real estate on properties owned. Excludes real estate assets taken in settlement of troubled loans through surrender or foreclosure by banks.",
        "label": "Other Real Estate, Roll Forward [Table Text Block]",
        "terseLabel": "Schedule of Other Real Estate Owned"
       }
      }
     },
     "localname": "OtherRealEstateRollForwardTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureOtherRealEstateOwnedOreoTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCategoriesOfInvestmentsDomain": {
     "auth_ref": [
      "r259"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Provides the categories of debt securities, available-for-sale or held-to-maturity, on which an entity may recognize other than temporary impairments (OTTI) for which a portion related to credit losses has been recognized in earnings and a portion related to all other factors has been recognized in other comprehensive income.",
        "label": "Other than Temporary Impairment, Credit Losses Recognized in Earnings, Categories of Investments [Domain]"
       }
      }
     },
     "localname": "OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCategoriesOfInvestmentsDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PassMember": {
     "auth_ref": [
      "r207",
      "r292"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A category of financing receivables not considered to be special mention, substandard, doubtful, and loss receivables.",
        "label": "Pass"
       }
      }
     },
     "localname": "PassMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PastDueFinancingReceivablesTableTextBlock": {
     "auth_ref": [
      "r213",
      "r214",
      "r284",
      "r302"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of aging analysis for financing receivable.",
        "label": "Past Due Financing Receivables [Table Text Block]",
        "terseLabel": "Past Due Financing Receivables"
       }
      }
     },
     "localname": "PastDueFinancingReceivablesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_PaymentsForOriginationOfMortgageLoansHeldForSale": {
     "auth_ref": [
      "r82",
      "r87"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 9.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of cash paid for the origination of mortgages that are held for sale.",
        "label": "Payments for Origination of Mortgage Loans Held-for-sale",
        "negatedTerseLabel": "Origination of loans held for sale"
       }
      }
     },
     "localname": "PaymentsForOriginationOfMortgageLoansHeldForSale",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsForProceedsFromFederalHomeLoanBankStock": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 11.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow (inflow) from acquisition (sale) of Federal Home Loan Bank (FHLBank) stock.",
        "label": "Payments for (Proceeds from) Federal Home Loan Bank Stock",
        "negatedTerseLabel": "Change in FHLB stock, net"
       }
      }
     },
     "localname": "PaymentsForProceedsFromFederalHomeLoanBankStock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsForRepurchaseOfCommonStock": {
     "auth_ref": [
      "r77"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 8.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash outflow to reacquire common stock during the period.",
        "label": "Payments for Repurchase of Common Stock",
        "negatedTerseLabel": "Common stock repurchased"
       }
      }
     },
     "localname": "PaymentsForRepurchaseOfCommonStock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsOfDividends": {
     "auth_ref": [
      "r77"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests.",
        "label": "Payments of Dividends",
        "negatedTerseLabel": "Dividends paid on common stock"
       }
      }
     },
     "localname": "PaymentsOfDividends",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquireHeldToMaturitySecurities": {
     "auth_ref": [
      "r74",
      "r225"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow through purchase of long-term held-to-maturity securities.",
        "label": "Payments to Acquire Held-to-maturity Securities",
        "negatedLabel": "Purchases"
       }
      }
     },
     "localname": "PaymentsToAcquireHeldToMaturitySecurities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquireLoansHeldForInvestment": {
     "auth_ref": [
      "r74"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 6.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash outflow associated with purchasing loans held for investment purposes during the period.",
        "label": "Payments to Acquire Loans Held-for-investment",
        "negatedLabel": "Purchase of portfolio loans"
       }
      }
     },
     "localname": "PaymentsToAcquireLoansHeldForInvestment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquireMarketableSecurities": {
     "auth_ref": [
      "r225"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow for purchase of marketable security.",
        "label": "Payments for (Proceeds from) Investments",
        "negatedTerseLabel": "Purchases"
       }
      }
     },
     "localname": "PaymentsToAcquireMarketableSecurities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquirePropertyPlantAndEquipment": {
     "auth_ref": [
      "r75"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 9.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.",
        "label": "Payments to Acquire Property, Plant, and Equipment",
        "negatedTerseLabel": "Purchase of premises and equipment"
       }
      }
     },
     "localname": "PaymentsToAcquirePropertyPlantAndEquipment",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PlanNameAxis": {
     "auth_ref": [
      "r406",
      "r429"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by plan name for share-based payment arrangement.",
        "label": "Plan Name [Axis]"
       }
      }
     },
     "localname": "PlanNameAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PlanNameDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Plan name for share-based payment arrangement.",
        "label": "Plan Name [Domain]"
       }
      }
     },
     "localname": "PlanNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PledgedFinancialInstrumentsNotSeparatelyReportedLoansReceivablePledgedForFederalHomeLoanBankDebt": {
     "auth_ref": [
      "r606"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The carrying amount, as of the date of the latest financial statement presented, of loans receivable which are owned but transferred to serve as collateral for the payment of FHLB debt obligations, and for which the transferee is not permitted to sell or re-pledge them to an unrelated party.",
        "label": "Pledged Financial Instruments, Not Separately Reported, Loans Receivable, for Federal Home Loan Bank Debt",
        "terseLabel": "Loans that qualify as collateral for FHLB advances"
       }
      }
     },
     "localname": "PledgedFinancialInstrumentsNotSeparatelyReportedLoansReceivablePledgedForFederalHomeLoanBankDebt",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesForFederalHomeLoanBank": {
     "auth_ref": [
      "r606"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The carrying amount as of the date of the latest financial statement presented of securities which are owned but transferred to serve as collateral for FHLB debt obligations, and for which the transferee does not have the right by contract or custom to sell or re-pledge them to an unrelated party.",
        "label": "Pledged Financial Instruments, Not Separately Reported, Securities for Federal Home Loan Bank",
        "terseLabel": "Pledged securities to secure public deposits"
       }
      }
     },
     "localname": "PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesForFederalHomeLoanBank",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PledgedStatusAxis": {
     "auth_ref": [
      "r459",
      "r465"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by pledged or not pledged status of asset owned by entity.",
        "label": "Pledged Status [Axis]"
       }
      }
     },
     "localname": "PledgedStatusAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PledgedStatusDomain": {
     "auth_ref": [
      "r459",
      "r465"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Pledged or not pledged status of asset owned by entity.",
        "label": "Pledged Status [Domain]"
       }
      }
     },
     "localname": "PledgedStatusDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PortionAtFairValueFairValueDisclosureMember": {
     "auth_ref": [
      "r539"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Measured at fair value for financial reporting purposes.",
        "label": "Portion at Fair Value Measurement"
       }
      }
     },
     "localname": "PortionAtFairValueFairValueDisclosureMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsFairValueByBalanceSheetGroupingDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PreferredStockParOrStatedValuePerShare": {
     "auth_ref": [
      "r12",
      "r367"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.",
        "label": "Preferred Stock, Par or Stated Value Per Share",
        "terseLabel": "Preferred stock par value, in dollars per share"
       }
      }
     },
     "localname": "PreferredStockParOrStatedValuePerShare",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_PreferredStockSharesAuthorized": {
     "auth_ref": [
      "r12"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.",
        "label": "Preferred Stock, Shares Authorized",
        "terseLabel": "Preferred stock, shares authorized"
       }
      }
     },
     "localname": "PreferredStockSharesAuthorized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_PreferredStockSharesIssued": {
     "auth_ref": [
      "r12",
      "r367"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt.",
        "label": "Preferred Stock, Shares Issued",
        "terseLabel": "Preferred stock, shares issued"
       }
      }
     },
     "localname": "PreferredStockSharesIssued",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_PreferredStockSharesOutstanding": {
     "auth_ref": [
      "r12"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.",
        "label": "Preferred Stock, Shares Outstanding",
        "terseLabel": "Preferred stock, shares outstanding"
       }
      }
     },
     "localname": "PreferredStockSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_PreferredStockValue": {
     "auth_ref": [
      "r12",
      "r583"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate par or stated value of issued nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable preferred shares, par value and other disclosure concepts are in another section within stockholders' equity.",
        "label": "Preferred Stock, Value, Issued",
        "terseLabel": "Preferred stock, $.01 par value; 5,000,000 shares authorized; none issued or outstanding"
       }
      }
     },
     "localname": "PreferredStockValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromFederalHomeLoanBankBorrowings": {
     "auth_ref": [
      "r76"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash inflow from Federal Home Loan Bank (FHLBank) borrowing, classified as financing activity.",
        "label": "Proceeds from Federal Home Loan Bank Borrowings",
        "terseLabel": "Proceeds from borrowings"
       }
      }
     },
     "localname": "ProceedsFromFederalHomeLoanBankBorrowings",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromLifeInsurancePolicies": {
     "auth_ref": [
      "r73",
      "r83"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 10.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash inflow for proceeds from settlement of corporate-owned life insurance policy, classified as investing activities. Includes, but is not limited to, bank-owned life insurance policy.",
        "label": "Proceeds from Life Insurance Policy",
        "terseLabel": "Proceeds from bank owned life insurance death benefits"
       }
      }
     },
     "localname": "ProceedsFromLifeInsurancePolicies",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities": {
     "auth_ref": [
      "r71",
      "r72",
      "r225"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash inflow from maturity, prepayment and call of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities",
        "terseLabel": "Maturities, prepayments, and calls"
       }
      }
     },
     "localname": "ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities": {
     "auth_ref": [
      "r72",
      "r225"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash inflow associated with the maturity, prepayments and calls (requests for early payments) of debt securities designated as held-to-maturity.",
        "label": "Proceeds from Maturities, Prepayments and Calls of Held-to-maturity Securities",
        "terseLabel": "Maturities of certificates of deposit at other financial institutions"
       }
      }
     },
     "localname": "ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromNotesPayable": {
     "auth_ref": [
      "r76"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash inflow from a borrowing supported by a written promise to pay an obligation.",
        "label": "Proceeds from Notes Payable",
        "terseLabel": "Net proceeds from issuance of subordinated notes"
       }
      }
     },
     "localname": "ProceedsFromNotesPayable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt": {
     "auth_ref": [
      "r71",
      "r72",
      "r225"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash inflow from sale of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Proceeds from Sale of Debt Securities, Available-for-sale",
        "terseLabel": "Proceeds from sale of available-for-sale securities"
       }
      }
     },
     "localname": "ProceedsFromSaleOfAvailableForSaleSecuritiesDebt",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromSaleOfLoansHeldForSale": {
     "auth_ref": [
      "r79",
      "r82"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 10.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash inflow resulting from the sale of loans classified as held-for-sale, including proceeds from loans sold through mortgage securitization.",
        "label": "Proceeds from Sale of Loans Held-for-sale",
        "terseLabel": "Proceeds from sale of loans held for sale"
       }
      }
     },
     "localname": "ProceedsFromSaleOfLoansHeldForSale",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromSaleOfLoansReceivable": {
     "auth_ref": [
      "r72"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 7.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash inflow associated with the sale of loans receivables arising from the financing of goods and services.",
        "label": "Proceeds from Sale of Loans Receivable",
        "terseLabel": "Proceeds from sale of portfolio loans"
       }
      }
     },
     "localname": "ProceedsFromSaleOfLoansReceivable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans": {
     "auth_ref": [
      "r73"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 8.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash inflow from proceeds From Sales of Wholly Owned Real Estate and Real Estate Acquired in Settlement of Loans.",
        "label": "Proceeds from Sale of Wholly Owned Real Estate and Real Estate Acquired in Settlement of Loans",
        "terseLabel": "Proceeds from sale of OREO, net"
       }
      }
     },
     "localname": "ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProfessionalFees": {
     "auth_ref": [
      "r737",
      "r738"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 8.0,
       "parentTag": "us-gaap_NoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A fee charged for services from professionals such as doctors, lawyers and accountants. The term is often expanded to include other professions, for example, pharmacists charging to maintain a medicinal profile of a client or customer.",
        "label": "Professional Fees",
        "terseLabel": "Professional and board fees"
       }
      }
     },
     "localname": "ProfessionalFees",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProfitLoss": {
     "auth_ref": [
      "r6",
      "r51",
      "r54",
      "r59",
      "r81",
      "r99",
      "r109",
      "r122",
      "r123",
      "r159",
      "r171",
      "r175",
      "r178",
      "r181",
      "r267",
      "r350",
      "r351",
      "r352",
      "r354",
      "r355",
      "r356",
      "r357",
      "r358",
      "r359",
      "r360",
      "r458",
      "r462",
      "r463",
      "r467",
      "r468",
      "r520",
      "r544",
      "r682"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.",
        "label": "Net Income (Loss), Including Portion Attributable to Noncontrolling Interest",
        "terseLabel": "Net income"
       }
      }
     },
     "localname": "ProfitLoss",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentNet": {
     "auth_ref": [
      "r8",
      "r9",
      "r326",
      "r583",
      "r692",
      "r709"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 10.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.",
        "label": "Property, Plant and Equipment, Net",
        "terseLabel": "Premises and equipment, net"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentNet",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProvisionForLoanAndLeaseLosses": {
     "auth_ref": [
      "r89",
      "r194",
      "r672"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest",
       "weight": -1.0
      },
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      },
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 2.0,
       "parentTag": "us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of expense related to estimated loss from loan and lease transactions.",
        "label": "Provision for Loan and Lease Losses",
        "negatedLabel": "Benefit (provision) for loan losses",
        "terseLabel": "Provision for credit losses",
        "verboseLabel": "PROVISION FOR CREDIT LOSSES"
       }
      }
     },
     "localname": "ProvisionForLoanAndLeaseLosses",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProvisionForLoanLeaseAndOtherLosses": {
     "auth_ref": [
      "r89",
      "r194",
      "r672"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.",
        "label": "Provision for Loan, Lease, and Other Losses",
        "netLabel": "Provision for loan losses"
       }
      }
     },
     "localname": "ProvisionForLoanLeaseAndOtherLosses",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RealEstateLoanMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loan to finance the purchase of real estate, including but not limited to, land or building.",
        "label": "Total real estate loans"
       }
      }
     },
     "localname": "RealEstateLoanMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RealEstateMember": {
     "auth_ref": [
      "r384"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Property consisting of land, land improvement and buildings.",
        "label": "Real Estate"
       }
      }
     },
     "localname": "RealEstateMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RealEstateOwnedTextBlock": {
     "auth_ref": [
      "r191"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for real estate owned (as defined). Generally, the largest component of real estate owned by lenders is assets taken in settlement of troubled loans through surrender or foreclosure. Real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned.",
        "label": "Real Estate Owned [Text Block]",
        "terseLabel": "OTHER REAL ESTATE OWNED (\"OREO\")"
       }
      }
     },
     "localname": "RealEstateOwnedTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureOtherRealEstateOwnedOreo"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ReceivablesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - LOANS"
       }
      }
     },
     "localname": "ReceivablesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock": {
     "auth_ref": [
      "r694",
      "r695",
      "r696",
      "r698",
      "r699",
      "r700",
      "r702",
      "r703"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for regulatory capital requirement for depository and lending institutions. Institutions include, but not are not limited to, finance company, insured depository institution, bank holding company, savings and loan association holding company, bank and savings institution not federally insured, mortgage company, foreign financial institution and credit union.",
        "label": "Regulatory Capital Requirements under Banking Regulations [Text Block]",
        "terseLabel": "REGULATORY CAPITAL"
       }
      }
     },
     "localname": "RegulatoryCapitalRequirementsUnderBankingRegulationsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRegulatoryCapital"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_RepaymentsOfFederalHomeLoanBankBorrowings": {
     "auth_ref": [
      "r78"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow for repayment of Federal Home Loan Bank (FHLBank) borrowing, classified as financing activity.",
        "label": "Repayments of Federal Home Loan Bank Borrowings",
        "negatedLabel": "Repayments of borrowings"
       }
      }
     },
     "localname": "RepaymentsOfFederalHomeLoanBankBorrowings",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RepaymentsOfNotesPayable": {
     "auth_ref": [
      "r78"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows": {
       "order": 6.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash outflow for a borrowing supported by a written promise to pay an obligation.",
        "label": "Repayments of Notes Payable",
        "negatedLabel": "Repayment of subordinated notes"
       }
      }
     },
     "localname": "RepaymentsOfNotesPayable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ResidentialMortgageMember": {
     "auth_ref": [
      "r301"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Loan to purchase or refinance residential real estate for example, but not limited to, a home, in which the real estate itself serves as collateral for the loan.",
        "label": "Residential Mortgage"
       }
      }
     },
     "localname": "ResidentialMortgageMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RestrictedStockMember": {
     "auth_ref": [
      "r137"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Stock including a provision that prohibits sale or substantive sale of an equity instrument for a specified period of time or until specified performance conditions are met.",
        "label": "Restricted stock awards"
       }
      }
     },
     "localname": "RestrictedStockMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RetainedEarningsAccumulatedDeficit": {
     "auth_ref": [
      "r16",
      "r372",
      "r437",
      "r583",
      "r707",
      "r729",
      "r734"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cumulative amount of the reporting entity's undistributed earnings or deficit.",
        "label": "Retained Earnings (Accumulated Deficit)",
        "terseLabel": "Retained earnings",
        "verboseLabel": "Increase in retained earnings"
       }
      }
     },
     "localname": "RetainedEarningsAccumulatedDeficit",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RetainedEarningsMember": {
     "auth_ref": [
      "r2",
      "r105",
      "r106",
      "r107",
      "r110",
      "r120",
      "r123",
      "r272",
      "r434",
      "r435",
      "r436",
      "r451",
      "r452",
      "r518",
      "r725",
      "r727"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cumulative amount of the reporting entity's undistributed earnings or deficit.",
        "label": "Retained Earnings"
       }
      }
     },
     "localname": "RetainedEarningsMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "REVENUE FROM CONTRACTS WITH CUSTOMERS"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax": {
     "auth_ref": [
      "r150",
      "r151",
      "r170",
      "r176",
      "r177",
      "r183",
      "r184",
      "r187",
      "r381",
      "r382",
      "r641"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomersDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.",
        "label": "Revenue from Contract with Customer, Excluding Assessed Tax",
        "terseLabel": "Noninterest income (in-scope of Topic 606)"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerExcludingAssessedTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomersDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax": {
     "auth_ref": [
      "r150",
      "r151",
      "r170",
      "r176",
      "r177",
      "r183",
      "r184",
      "r187",
      "r381",
      "r382",
      "r641"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 1.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.",
        "label": "Fees and Commissions, Depositor Accounts",
        "terseLabel": "Service charges and fee income"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerIncludingAssessedTax",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerTextBlock": {
     "auth_ref": [
      "r373",
      "r374",
      "r375",
      "r376",
      "r377",
      "r378",
      "r379",
      "r380",
      "r383",
      "r386"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.",
        "label": "Revenue from Contract with Customer [Text Block]",
        "terseLabel": "REVENUE FROM CONTRACTS WITH CUSTOMERS"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomers"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_RevenueNotFromContractWithCustomerExcludingInterestIncome": {
     "auth_ref": [
      "r663"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomersDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_NoninterestIncome",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, excluding interest income, of revenue not accounted for under Topic 606.",
        "label": "Revenue Not from Contract with Customer, Excluding Interest Income",
        "terseLabel": "Noninterest income (out-of-scope of Topic 606)"
       }
      }
     },
     "localname": "RevenueNotFromContractWithCustomerExcludingInterestIncome",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomersDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RevenuesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Revenues [Abstract]",
        "terseLabel": "INTEREST INCOME"
       }
      }
     },
     "localname": "RevenuesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable": {
     "auth_ref": [
      "r27"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule itemizing specific types of trade accounts and notes receivable, and for each the gross carrying value, allowance, and net carrying value as of the balance sheet date. Presentation is categorized by current, noncurrent and unclassified receivables.",
        "label": "Schedule of Accounts, Notes, Loans and Financing Receivable [Table]",
        "terseLabel": "Schedule of Accounts, Notes, Loans and Financing Receivable [Table]"
       }
      }
     },
     "localname": "ScheduleOfAccountsNotesLoansAndFinancingReceivableTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock": {
     "auth_ref": [
      "r27"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the various types of trade accounts and notes receivable and for each the gross carrying value, allowance, and net carrying value as of the balance sheet date. Presentation is categorized by current, noncurrent and unclassified receivables.",
        "label": "Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]",
        "terseLabel": "Schedule of Accounts, Notes, Loans and Financing Receivable"
       }
      }
     },
     "localname": "ScheduleOfAccountsNotesLoansAndFinancingReceivableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the reconciliation of available-for-sale securities from cost basis to fair value.",
        "label": "Schedule of Available-for-sale Securities Reconciliation [Table Text Block]",
        "terseLabel": "Schedule of Available-for-sale Securities Reconciliation"
       }
      }
     },
     "localname": "ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable": {
     "auth_ref": [
      "r697",
      "r701"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A table disclosing the capital amounts and ratios as of the balance sheet date indicating whether the entity or entities are in compliance with regulatory capital requirements, by entity.",
        "label": "Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table]",
        "terseLabel": "Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table]"
       }
      }
     },
     "localname": "ScheduleOfComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRegulatoryCapitalRegulatoryCapitalRatiosPolicyDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfDerivativeInstrumentsGainLossInStatementOfFinancialPerformanceTextBlock": {
     "auth_ref": [
      "r479",
      "r489",
      "r494"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the location and amount of derivative instruments and nonderivative instruments designated as hedging instruments reported before netting adjustments, and the amount of gain (loss) on derivative instruments and nonderivative instruments designated and qualified as hedging instruments.",
        "label": "Derivative Instruments, Gain (Loss) [Table Text Block]",
        "terseLabel": "Schedule of effect of fair value and cash flow hedge accounting on the income statement"
       }
      }
     },
     "localname": "ScheduleOfDerivativeInstrumentsGainLossInStatementOfFinancialPerformanceTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock": {
     "auth_ref": [
      "r484"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the location and fair value amounts of derivative instruments (and nonderivative instruments that are designated and qualify as hedging instruments) reported in the statement of financial position.",
        "label": "Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]",
        "terseLabel": "Schedule of Derivative Instruments"
       }
      }
     },
     "localname": "ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock": {
     "auth_ref": [
      "r136"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of an entity's basic and diluted earnings per share calculations, including a reconciliation of numerators and denominators of the basic and diluted per-share computations for income from continuing operations.",
        "label": "Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]",
        "terseLabel": "Schedule of Earnings Per Share, Basic and Diluted"
       }
      }
     },
     "localname": "ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock": {
     "auth_ref": [
      "r522",
      "r523"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of assets and liabilities, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, that are measured at fair value on a recurring basis. The disclosures contemplated herein include the fair value measurements at the reporting date by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3).",
        "label": "Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]",
        "terseLabel": "Schedule of assets and liabilities measured at fair value on a recurring basis"
       }
      }
     },
     "localname": "ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfFairValueHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock": {
     "auth_ref": [
      "r485"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure for fair value hedging instruments of (a) the location and amount of gains and losses reported in the statement of financial performance and (b) the location and fair value amounts of the instruments reported in the statement of financial position.",
        "label": "Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]",
        "terseLabel": "Schedule of cumulative-basis adjustment for fair value hedges"
       }
      }
     },
     "localname": "ScheduleOfFairValueHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDerivativesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfFairValueOffBalanceSheetRisksTable": {
     "auth_ref": [
      "r541",
      "r542"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule detailing the information required and determined to be disclosed regarding the fair value of financial assets and financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.",
        "label": "Schedule of Fair Value, Off-balance Sheet Risks [Table]",
        "terseLabel": "Schedule of Fair Value, Off-balance Sheet Risks [Table]"
       }
      }
     },
     "localname": "ScheduleOfFairValueOffBalanceSheetRisksTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsTables",
      "http://www.fsbwa.com/role/DisclosureServicingRightsValuationAssumptionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable": {
     "auth_ref": [
      "r283",
      "r779"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about allowance for credit loss on financing receivable.",
        "label": "Schedule of Financing Receivable, Allowance for Credit Losses [Table]",
        "terseLabel": "Schedule of Financing Receivable, Allowance for Credit Losses [Table]"
       }
      }
     },
     "localname": "ScheduleOfFinancingReceivableAllowanceForCreditLossesTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansCompositionOfLoanPortfolioDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable": {
     "auth_ref": [
      "r292",
      "r301"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about credit quality indicator for financing receivable.",
        "label": "Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table]",
        "terseLabel": "Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table]"
       }
      }
     },
     "localname": "ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAmortizedCostOfDebtDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfCollateralDependentImpairedLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAmortizedCostBasisOfLoansDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfFinancingReceivablesNonAccrualStatusTableTextBlock": {
     "auth_ref": [
      "r213",
      "r288"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of financing receivable on nonaccrual status.",
        "label": "Financing Receivable, Nonaccrual [Table Text Block]",
        "terseLabel": "Schedule of amortized cost basis of loans"
       }
      }
     },
     "localname": "ScheduleOfFinancingReceivablesNonAccrualStatusTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfFinancingReceivablesPastDueTable": {
     "auth_ref": [
      "r284",
      "r302"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about aging analysis for financing receivable.",
        "label": "Schedule of Financing Receivables Past Due [Table]",
        "terseLabel": "Schedule of Financing Receivables Past Due [Table]"
       }
      }
     },
     "localname": "ScheduleOfFinancingReceivablesPastDueTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAgingAnalysisOfPastDueLoansDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable": {
     "auth_ref": [
      "r320",
      "r321",
      "r642"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.",
        "label": "Schedule of Finite-Lived Intangible Assets [Table]"
       }
      }
     },
     "localname": "ScheduleOfFiniteLivedIntangibleAssetsTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfImpairedFinancingReceivableTable": {
     "auth_ref": [
      "r205"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule of the recorded investment, unpaid principal balance, associated allowance, average recorded investment, accounting policies, and interest income recognized on the accrual and cash basis for impaired financing receivables by class of financing receivable.",
        "label": "Schedule of Impaired Financing Receivable [Table]",
        "terseLabel": "Schedule of Impaired Financing Receivable [Table]"
       }
      }
     },
     "localname": "ScheduleOfImpairedFinancingReceivableTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAverageRecordedInvestmentDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansFinancingReceivablesRelatedAllowanceRecordedAndNoRelatedAllowanceRecordedDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock": {
     "auth_ref": [
      "r113",
      "r117",
      "r143",
      "r144"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of changes in accounting principles, including adoption of new accounting pronouncements, that describes the new methods, amount and effects on financial statement line items.",
        "label": "Accounting Standards Update and Change in Accounting Principle [Table Text Block]",
        "terseLabel": "Schedule of adoption"
       }
      }
     },
     "localname": "ScheduleOfNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfNonvestedShareActivityTableTextBlock": {
     "auth_ref": [
      "r417"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the changes in outstanding nonvested shares.",
        "label": "Schedule of Nonvested Share Activity [Table Text Block]",
        "terseLabel": "Summary of Nonvested Awards"
       }
      }
     },
     "localname": "ScheduleOfNonvestedShareActivityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable": {
     "auth_ref": [
      "r159",
      "r162",
      "r174",
      "r317"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A table disclosing the profit or loss and total assets for each reportable segment of the entity. An entity discloses certain information on each reportable segment if the amounts (a) are included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) are otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss.",
        "label": "Schedule of Segment Reporting Information, by Segment [Table]",
        "terseLabel": "Schedule of Segment Reporting Information, by Segment [Table]"
       }
      }
     },
     "localname": "ScheduleOfSegmentReportingInformationBySegmentTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock": {
     "auth_ref": [
      "r159",
      "r162",
      "r174",
      "r317"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the profit or loss and total assets for each reportable segment. An entity discloses certain information on each reportable segment if the amounts (a) are included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) are otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss.",
        "label": "Schedule of Segment Reporting Information, by Segment [Table Text Block]",
        "terseLabel": "Schedule of Segment Reporting Information, by Segment"
       }
      }
     },
     "localname": "ScheduleOfSegmentReportingInformationBySegmentTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfSensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrServicingLiabilitiesTextBlock": {
     "auth_ref": [
      "r601"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of a sensitivity analysis or stress test showing the hypothetical effect on the fair value of the transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) of two or more unfavorable variations from the expected levels for each key assumption that is reported, independently determined from any change in another key assumption, and a description of the objectives, methodology, and limitations of the sensitivity analysis or stress test.",
        "label": "Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table Text Block]",
        "terseLabel": "Key economic assumptions and the sensitivity of the current fair value for single family mortgage servicing rights"
       }
      }
     },
     "localname": "ScheduleOfSensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrServicingLiabilitiesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfServicingAssetsAtAmortizedValueTextBlock": {
     "auth_ref": [
      "r625"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of activity in the balance of servicing assets subsequently measured at amortized cost. Includes, but is not limited to, beginning and ending balances, additions, disposals, and amortization.",
        "label": "Servicing Asset at Amortized Cost [Table Text Block]",
        "terseLabel": "Summary of servicing rights activity"
       }
      }
     },
     "localname": "ScheduleOfServicingAssetsAtAmortizedValueTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable": {
     "auth_ref": [
      "r406",
      "r429"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about share-based payment arrangement.",
        "label": "Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]",
        "terseLabel": "Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]"
       }
      }
     },
     "localname": "ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock": {
     "auth_ref": [
      "r411",
      "r422",
      "r424"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure for stock option plans. Includes, but is not limited to, outstanding awards at beginning and end of year, grants, exercises, forfeitures, and weighted-average grant date fair value.",
        "label": "Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]",
        "terseLabel": "Summary of Stock Option Awards"
       }
      }
     },
     "localname": "ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Debt and Equity Securities, FV-NI [Line Items]"
       }
      }
     },
     "localname": "ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock": {
     "auth_ref": [
      "r257"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "For all investments in an unrealized loss position, including those for which other-than-temporary impairments have not been recognized in earnings (including investments for which a portion of an other-than-temporary impairment has been recognized in other comprehensive income), a tabular disclosure of the aggregate related fair value of investments with unrealized losses and the aggregate amount of unrealized losses (that is, the amount by which amortized cost basis exceeds fair value).",
        "label": "Schedule of Unrealized Loss on Investments [Table Text Block]",
        "terseLabel": "Schedule of Unrealized Loss on Investments"
       }
      }
     },
     "localname": "ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureInvestmentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfValuationAllowanceForImpairmentOfRecognizedServicingAssetsTextBlock": {
     "auth_ref": [
      "r635"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the activity by class in any valuation allowance for impairment of recognized servicing assets - including beginning and ending balances, aggregate additions charged and recoveries credited to operations, and aggregate write-downs charged against allowance.",
        "label": "Schedule of Valuation Allowance for Impairment of Recognized Servicing Assets [Table Text Block]",
        "terseLabel": "Schedule of Valuation Allowance for Impairment of Recognized Servicing Assets"
       }
      }
     },
     "localname": "ScheduleOfValuationAllowanceForImpairmentOfRecognizedServicingAssetsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock": {
     "auth_ref": [
      "r321"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the amount of amortization expense expected to be recorded in succeeding fiscal years for finite-lived intangible assets.",
        "label": "Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]",
        "terseLabel": "Schedule of amortization expense"
       }
      }
     },
     "localname": "ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureGoodwillAndOtherIntangibleAssetsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SegmentDomain": {
     "auth_ref": [
      "r146",
      "r150",
      "r151",
      "r152",
      "r153",
      "r154",
      "r155",
      "r156",
      "r157",
      "r158",
      "r159",
      "r160",
      "r161",
      "r170",
      "r171",
      "r172",
      "r173",
      "r175",
      "r176",
      "r177",
      "r178",
      "r179",
      "r181",
      "r187",
      "r330",
      "r331",
      "r718"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Components of an entity that engage in business activities from which they may earn revenue and incur expenses, including transactions with other components of the same entity.",
        "label": "Segments [Domain]"
       }
      }
     },
     "localname": "SegmentDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SegmentReportingAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "BUSINESS SEGMENTS"
       }
      }
     },
     "localname": "SegmentReportingAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_SegmentReportingDisclosureTextBlock": {
     "auth_ref": [
      "r146",
      "r148",
      "r149",
      "r159",
      "r163",
      "r175",
      "r179",
      "r180",
      "r181",
      "r182",
      "r183",
      "r186",
      "r187",
      "r188"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.",
        "label": "Segment Reporting Disclosure [Text Block]",
        "terseLabel": "BUSINESS SEGMENTS"
       }
      }
     },
     "localname": "SegmentReportingDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegments"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SegmentReportingInformationLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Segment Reporting Information [Line Items]",
        "terseLabel": "Segment Reporting Information [Line Items]"
       }
      }
     },
     "localname": "SegmentReportingInformationLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SegmentReportingPolicyPolicyTextBlock": {
     "auth_ref": [
      "r164",
      "r165",
      "r166",
      "r167",
      "r168",
      "r169",
      "r184"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy for segment reporting.",
        "label": "Segment Reporting, Policy [Policy Text Block]",
        "terseLabel": "Segment Reporting"
       }
      }
     },
     "localname": "SegmentReportingPolicyPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SellingGeneralAndAdministrativeExpense": {
     "auth_ref": [
      "r68"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome": {
       "order": 9.0,
       "parentTag": "us-gaap_NoninterestExpense",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.",
        "label": "Selling, General and Administrative Expense",
        "terseLabel": "Operations"
       }
      }
     },
     "localname": "SellingGeneralAndAdministrativeExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfIncome"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ServicingAsset": {
     "auth_ref": [
      "r613"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 14.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate amount of servicing assets that are subsequently measured at fair value and servicing assets that are subsequently measured using the amortization method.",
        "label": "Servicing Asset",
        "verboseLabel": "Servicing rights, held at the lower of cost or fair value"
       }
      }
     },
     "localname": "ServicingAsset",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ServicingAssetAtAmortizedValue": {
     "auth_ref": [
      "r611",
      "r612",
      "r626"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amortized amount of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.",
        "label": "Servicing Asset at Amortized Cost",
        "periodEndLabel": "Ending balance, at the lower of cost or fair value",
        "periodStartLabel": "Beginning balance, at the lower of cost or fair value"
       }
      }
     },
     "localname": "ServicingAssetAtAmortizedValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsServicingRightsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ServicingAssetAtAmortizedValueAmortization1": {
     "auth_ref": [
      "r629"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of amortization of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.",
        "label": "Servicing Asset at Amortized Cost, Amortization",
        "negatedTerseLabel": "Servicing rights amortized"
       }
      }
     },
     "localname": "ServicingAssetAtAmortizedValueAmortization1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsServicingRightsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ServicingAssetAtFairValueAdditions": {
     "auth_ref": [
      "r620"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The value of new servicing assets, subsequently measured at fair value, acquired or created during the current period through purchases or from transfers of financial assets.",
        "label": "Servicing Asset at Fair Value, Additions",
        "terseLabel": "Additions"
       }
      }
     },
     "localname": "ServicingAssetAtFairValueAdditions",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsServicingRightsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ServicingAssetAtFairValueAmount": {
     "auth_ref": [
      "r611",
      "r612",
      "r613",
      "r619"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.",
        "label": "Servicing Asset at Fair Value, Amount",
        "terseLabel": "Fair value MSR"
       }
      }
     },
     "localname": "ServicingAssetAtFairValueAmount",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ServicingAssetAtFairValueAmountRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Servicing Asset at Fair Value, Amount [Roll Forward]",
        "terseLabel": "Servicing Asset at Fair Value, Amount [Roll Forward]"
       }
      }
     },
     "localname": "ServicingAssetAtFairValueAmountRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsServicingRightsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueDiscountRate": {
     "auth_ref": [
      "r617"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Discount rate used to estimate the fair value of servicing assets and servicing liabilities.",
        "label": "Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Discount Rate",
        "terseLabel": "Discount rate",
        "verboseLabel": "Weighted average discount rate"
       }
      }
     },
     "localname": "ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueDiscountRate",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValuePrepaymentSpeed": {
     "auth_ref": [
      "r617"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Estimated rate of prepayments of principal on servicing assets and servicing liabilities.",
        "label": "Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Prepayment Speed",
        "terseLabel": "Conditional prepayment rate",
        "verboseLabel": "Conditional prepayment rate (\"CPR\")"
       }
      }
     },
     "localname": "ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValuePrepaymentSpeed",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueWeightedAverageLife1": {
     "auth_ref": [
      "r617"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average life of financial assets and financial liabilities, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Weighted Average Life",
        "verboseLabel": "Weighted average life in years"
       }
      }
     },
     "localname": "ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueWeightedAverageLife1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRightsValuationAssumptionsDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1": {
     "auth_ref": [
      "r407"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period",
        "terseLabel": "Award vesting period"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod": {
     "auth_ref": [
      "r416"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period",
        "verboseLabel": "Forfeited or expired ( in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r421"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value",
        "verboseLabel": "Forfeited or expired (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod": {
     "auth_ref": [
      "r419"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period",
        "terseLabel": "Granted (shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r419"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value",
        "terseLabel": "Granted (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber": {
     "auth_ref": [
      "r418"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number",
        "periodEndLabel": "Nonvested, Ending balance (in shares)",
        "periodStartLabel": "Nonvested, Beginning balance (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]",
        "terseLabel": "Shares"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r418"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value",
        "periodEndLabel": "Nonvested, Ending balance (in dollars per share)",
        "periodStartLabel": "Nonvested, Beginning balance (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]",
        "terseLabel": "Weighted-Average Grant-Date Fair Value Per Share"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms": {
     "auth_ref": [
      "r425"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms",
        "verboseLabel": "Weighted-average vesting period"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod": {
     "auth_ref": [
      "r420"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period",
        "terseLabel": "Less vested (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r420"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value",
        "terseLabel": "Less vested (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award [Line Items]",
        "terseLabel": "Share-based Compensation Arrangement by Share-based Payment Award [Line Items]"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized": {
     "auth_ref": [
      "r409"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of shares authorized for issuance under share-based payment arrangement.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized",
        "terseLabel": "Number of shares authorized (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant": {
     "auth_ref": [
      "r429"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant",
        "terseLabel": "Shares available for grant"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber": {
     "auth_ref": [
      "r414"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number",
        "terseLabel": "Exercisable (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice": {
     "auth_ref": [
      "r414"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price",
        "terseLabel": "Exercisable (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue": {
     "auth_ref": [
      "r423"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value",
        "terseLabel": "Less exercised"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue": {
     "auth_ref": [
      "r429"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value",
        "periodEndLabel": "Ending balance",
        "periodStartLabel": "Beginning balance"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber": {
     "auth_ref": [
      "r413",
      "r429"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of options outstanding, including both vested and non-vested options.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number",
        "periodEndLabel": "Outstanding, ending balance (in shares)",
        "periodStartLabel": "Outstanding, beginning balance (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]",
        "terseLabel": "Shares"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice": {
     "auth_ref": [
      "r412"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price",
        "periodEndLabel": "Outstanding, ending balance (in dollars per share)",
        "periodStartLabel": "Outstanding, beginning balance (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]",
        "terseLabel": "Weighted-Average Exercise Price"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue": {
     "auth_ref": [
      "r424"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value",
        "terseLabel": "Expected to vest, assuming a 0.31% annual forfeiture rate"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber": {
     "auth_ref": [
      "r425"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of fully vested and expected to vest options outstanding that can be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number",
        "terseLabel": "Expected to vest, assuming a 0.31% annual forfeiture rate (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice": {
     "auth_ref": [
      "r425"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price",
        "terseLabel": "Expected to vest, assuming a 0.31% annual forfeiture rate (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain": {
     "auth_ref": [
      "r404",
      "r410"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Award under share-based payment arrangement.",
        "label": "Equity Award [Domain]"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationRestrictedStockAwardsDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average price at which option holders acquired shares when converting their stock options into shares.",
        "label": "Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price",
        "terseLabel": "Less exercised (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationAwardTrancheOneMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "First portion of award under share-based payment arrangement differentiated by vesting feature, including, but not limited to, performance measure or service period.",
        "label": "One year vesting"
       }
      }
     },
     "localname": "ShareBasedCompensationAwardTrancheOneMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ShareBasedCompensationAwardTrancheThreeMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Third portion of award under share-based payment arrangement differentiated by vesting feature, including, but not limited to, performance measure or service period.",
        "label": "Five year vesting"
       }
      }
     },
     "localname": "ShareBasedCompensationAwardTrancheThreeMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ShareBasedCompensationAwardTrancheTwoMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Second portion of award under share-based payment arrangement differentiated by vesting feature, including, but not limited to, performance measure or service period.",
        "label": "Three year vesting"
       }
      }
     },
     "localname": "ShareBasedCompensationAwardTrancheTwoMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod": {
     "auth_ref": [
      "r408"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period",
        "terseLabel": "Award contractual life"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1": {
     "auth_ref": [
      "r426",
      "r438"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term",
        "terseLabel": "Expected term in years",
        "verboseLabel": "Outstanding, beginning balance"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1": {
     "auth_ref": [
      "r429"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value",
        "terseLabel": "Exercisable"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1": {
     "auth_ref": [
      "r429"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term",
        "terseLabel": "Exercisable"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2": {
     "auth_ref": [
      "r425"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term",
        "terseLabel": "Outstanding, ending balance",
        "verboseLabel": "Remaining weighted-average vesting period"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1": {
     "auth_ref": [
      "r425"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average remaining contractual term for fully vested and expected to vest options outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term",
        "terseLabel": "Expected to vest, assuming a 0.31% annual forfeiture rate, Weighted Average Remaining Contractual Term"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_SharesOutstanding": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of shares issued which are neither cancelled nor held in the treasury.",
        "label": "Shares, Outstanding",
        "periodEndLabel": "Balance (in shares)",
        "periodStartLabel": "Balance (in shares)"
       }
      }
     },
     "localname": "SharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShortTermLeaseCost": {
     "auth_ref": [
      "r570",
      "r576"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureLeasesComponentsOfLeaseCostAndSupplementalInformationRelatedToOperatingLeasesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_LeaseCost",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of short-term lease cost, excluding expense for lease with term of one month or less.",
        "label": "Short-term Lease, Cost",
        "terseLabel": "Short-term lease cost"
       }
      }
     },
     "localname": "ShortTermLeaseCost",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLeasesComponentsOfLeaseCostAndSupplementalInformationRelatedToOperatingLeasesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_SpecialMentionMember": {
     "auth_ref": [
      "r207",
      "r292"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A category of financing receivables considered to have potential weaknesses that deserve management's close attention. If left uncorrected, those potential weaknesses may result in a deterioration of the repayment prospects for the asset or of the creditor's position at some future date.",
        "label": "Special Mention"
       }
      }
     },
     "localname": "SpecialMentionMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_StatementBusinessSegmentsAxis": {
     "auth_ref": [
      "r5",
      "r146",
      "r150",
      "r151",
      "r152",
      "r153",
      "r154",
      "r155",
      "r156",
      "r157",
      "r158",
      "r159",
      "r160",
      "r161",
      "r170",
      "r171",
      "r172",
      "r173",
      "r175",
      "r176",
      "r177",
      "r178",
      "r179",
      "r181",
      "r187",
      "r317",
      "r328",
      "r330",
      "r331",
      "r718"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by business segments.",
        "label": "Segments [Axis]"
       }
      }
     },
     "localname": "StatementBusinessSegmentsAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBusinessSegmentsSegmentFinancialResultsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementEquityComponentsAxis": {
     "auth_ref": [
      "r2",
      "r26",
      "r57",
      "r58",
      "r59",
      "r105",
      "r106",
      "r107",
      "r110",
      "r120",
      "r123",
      "r145",
      "r272",
      "r371",
      "r372",
      "r434",
      "r435",
      "r436",
      "r451",
      "r452",
      "r518",
      "r554",
      "r555",
      "r556",
      "r557",
      "r558",
      "r560",
      "r725",
      "r726",
      "r727",
      "r787"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by component of equity.",
        "label": "Equity Components [Axis]"
       }
      }
     },
     "localname": "StatementEquityComponentsAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Statement [Line Items]",
        "terseLabel": "Statement [Line Items]"
       }
      }
     },
     "localname": "StatementLineItems",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomersDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfCashFlowsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "CONSOLIDATED STATEMENTS OF CASH FLOWS"
       }
      }
     },
     "localname": "StatementOfCashFlowsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfFinancialPositionAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "CONSOLIDATED BALANCE SHEETS"
       }
      }
     },
     "localname": "StatementOfFinancialPositionAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME"
       }
      }
     },
     "localname": "StatementOfIncomeAndComprehensiveIncomeAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfStockholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY"
       }
      }
     },
     "localname": "StatementOfStockholdersEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementTable": {
     "auth_ref": [
      "r105",
      "r106",
      "r107",
      "r145",
      "r641"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule reflecting a Statement of Income, Statement of Cash Flows, Statement of Financial Position, Statement of Shareholders' Equity and Other Comprehensive Income, or other statement as needed.",
        "label": "Statement [Table]",
        "terseLabel": "Statement [Table]"
       }
      }
     },
     "localname": "StatementTable",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRevenueFromContractsWithCustomersDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised": {
     "auth_ref": [
      "r12",
      "r13",
      "r371",
      "r372",
      "r415"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of share options (or share units) exercised during the current period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period",
        "terseLabel": "Stock options exercised, net (in shares)",
        "verboseLabel": "Less exercised (in shares)"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodSharesStockOptionsExercised",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockIssuedDuringPeriodValueEmployeeStockOwnershipPlan": {
     "auth_ref": [
      "r12",
      "r13",
      "r371",
      "r372",
      "r442"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate value of stock issued during the period as a result of employee stock ownership plan (ESOP).",
        "label": "Stock Issued During Period, Value, Employee Stock Ownership Plan",
        "terseLabel": "ESOP shares allocated"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodValueEmployeeStockOwnershipPlan",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross": {
     "auth_ref": [
      "r12",
      "r13",
      "r371",
      "r372"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate value of stock related to Restricted Stock Awards issued during the period.",
        "label": "Stock Issued During Period, Value, Restricted Stock Award, Gross",
        "terseLabel": "New credit standard (Topic 326) - impact in year of adoption"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodValueRestrictedStockAwardGross",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised": {
     "auth_ref": [
      "r26",
      "r371",
      "r372"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Value of stock issued as a result of the exercise of stock options.",
        "label": "Stock Issued During Period, Value, Stock Options Exercised",
        "terseLabel": "Stock options exercised, net"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodValueStockOptionsExercised",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockOptionMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Contracts conveying rights, but not obligations, to buy or sell a specific quantity of stock at a specified price during a specified period (an American option) or at a specified date (a European option).",
        "label": "Equity option"
       }
      }
     },
     "localname": "StockOptionMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationStockOptionActivityDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_StockRepurchasedDuringPeriodShares": {
     "auth_ref": [
      "r12",
      "r13",
      "r371",
      "r372"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.",
        "label": "Stock Repurchased During Period, Shares",
        "negatedTerseLabel": "Common stock repurchased - repurchase plan (in shares)"
       }
      }
     },
     "localname": "StockRepurchasedDuringPeriodShares",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockRepurchasedDuringPeriodValue": {
     "auth_ref": [
      "r12",
      "r13",
      "r371",
      "r372"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.",
        "label": "Stock Repurchased During Period, Value",
        "negatedTerseLabel": "Common stock repurchased - repurchase plan"
       }
      }
     },
     "localname": "StockRepurchasedDuringPeriodValue",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockholdersEquity": {
     "auth_ref": [
      "r13",
      "r18",
      "r19",
      "r99",
      "r215",
      "r267",
      "r544",
      "r583"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.",
        "label": "Stockholders' Equity Attributable to Parent",
        "periodEndLabel": "Balance",
        "periodStartLabel": "Balance",
        "totalLabel": "Total stockholders' equity"
       }
      }
     },
     "localname": "StockholdersEquity",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets",
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfChangesInStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Stockholders' Equity Attributable to Parent [Abstract]",
        "terseLabel": "STOCKHOLDERS' EQUITY"
       }
      }
     },
     "localname": "StockholdersEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SubsequentEventsPolicyPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy for reporting subsequent events.",
        "label": "Subsequent Events, Policy [Policy Text Block]",
        "terseLabel": "Subsequent Events"
       }
      }
     },
     "localname": "SubsequentEventsPolicyPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SubstandardMember": {
     "auth_ref": [
      "r207",
      "r292"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "A category of financing receivables that are inadequately protected by the current sound worth and paying capacity of the obligor or of the collateral pledged, if any. Loans so classified have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. They are characterized by the distinct possibility that the creditor will sustain some loss if the deficiencies are not corrected.",
        "label": "Substandard"
       }
      }
     },
     "localname": "SubstandardMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansRiskRatedLoanBalancesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SupplementalCashFlowInformationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Supplemental Cash Flow Information [Abstract]",
        "terseLabel": "SUPPLEMENTARY DISCLOSURES OF CASH FLOW INFORMATION"
       }
      }
     },
     "localname": "SupplementalCashFlowInformationAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_TierOneLeverageCapital": {
     "auth_ref": [
      "r697"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of Tier 1 leverage capital as defined by regulatory framework.",
        "label": "Tier One Leverage Capital"
       }
      }
     },
     "localname": "TierOneLeverageCapital",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRegulatoryCapitalRegulatoryCapitalRatiosPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized": {
     "auth_ref": [
      "r697"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of minimum Tier 1 leverage capital categorized as well capitalized as defined by regulatory framework for prompt corrective action.",
        "label": "Tier One Leverage Capital Required to be Well Capitalized",
        "terseLabel": "Tier 1 leverage capital, To be Well Capitalized Under Prompt Corrective Action Provisions, Amount"
       }
      }
     },
     "localname": "TierOneLeverageCapitalRequiredToBeWellCapitalized",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRegulatoryCapitalRegulatoryCapitalRatiosPolicyDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TierOneLeverageCapitalToAverageAssets": {
     "auth_ref": [
      "r697"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Ratio of Tier 1 capital to average assets as defined by regulatory framework.",
        "label": "Tier One Leverage Capital to Average Assets",
        "terseLabel": "Tier 1 leverage capital, Ratio"
       }
      }
     },
     "localname": "TierOneLeverageCapitalToAverageAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRegulatoryCapitalRegulatoryCapitalRatiosPolicyDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets": {
     "auth_ref": [
      "r697"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Ratio of Tier 1 risk-based capital to risk-weighted assets as defined by regulatory framework.",
        "label": "Tier One Risk Based Capital to Risk Weighted Assets",
        "verboseLabel": "Tier 1 risk-based capital, Ratio"
       }
      }
     },
     "localname": "TierOneRiskBasedCapitalToRiskWeightedAssets",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureRegulatoryCapitalRegulatoryCapitalRatiosPolicyDetails"
     ],
     "xbrltype": "pureItemType"
    },
    "us-gaap_TimeDepositMaturitiesRemainderOfFiscalYear": {
     "auth_ref": [],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsMaturitiesOfTimeDepositsForFuturePeriodsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_TimeDeposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposit maturing in remainder of current fiscal year. Time deposit includes, but is not limited to, certificate of deposit.",
        "label": "Time Deposit Maturities, Remainder of Fiscal Year",
        "terseLabel": "Maturing in 2022"
       }
      }
     },
     "localname": "TimeDepositMaturitiesRemainderOfFiscalYear",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsMaturitiesOfTimeDepositsForFuturePeriodsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TimeDepositMaturitiesYearFour": {
     "auth_ref": [
      "r348"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsMaturitiesOfTimeDepositsForFuturePeriodsDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_TimeDeposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposit maturing in fourth fiscal year following current fiscal year. Time deposit includes, but is not limited to, certificate of deposit. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Time Deposit Maturities, Year Four",
        "terseLabel": "Maturing in 2026"
       }
      }
     },
     "localname": "TimeDepositMaturitiesYearFour",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsMaturitiesOfTimeDepositsForFuturePeriodsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TimeDepositMaturitiesYearOne": {
     "auth_ref": [
      "r348"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsMaturitiesOfTimeDepositsForFuturePeriodsDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_TimeDeposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposit maturing in next fiscal year following current fiscal year. Time deposit includes, but is not limited to, certificate of deposit. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Time Deposit Maturities, Next Twelve Months",
        "terseLabel": "Maturing in 2023"
       }
      }
     },
     "localname": "TimeDepositMaturitiesYearOne",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsMaturitiesOfTimeDepositsForFuturePeriodsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TimeDepositMaturitiesYearThree": {
     "auth_ref": [
      "r348"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsMaturitiesOfTimeDepositsForFuturePeriodsDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_TimeDeposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposit maturing in third fiscal year following current fiscal year. Time deposit includes, but is not limited to, certificate of deposit. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Time Deposit Maturities, Year Three",
        "terseLabel": "Maturing in 2025"
       }
      }
     },
     "localname": "TimeDepositMaturitiesYearThree",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsMaturitiesOfTimeDepositsForFuturePeriodsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TimeDepositMaturitiesYearTwo": {
     "auth_ref": [
      "r348"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsMaturitiesOfTimeDepositsForFuturePeriodsDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_TimeDeposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposit maturing in second fiscal year following current fiscal year. Time deposit includes, but is not limited to, certificate of deposit. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Time Deposit Maturities, Year Two",
        "terseLabel": "Maturing in 2024"
       }
      }
     },
     "localname": "TimeDepositMaturitiesYearTwo",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsMaturitiesOfTimeDepositsForFuturePeriodsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TimeDeposits": {
     "auth_ref": [
      "r658",
      "r693"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsMaturitiesOfTimeDepositsForFuturePeriodsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposit liabilities, including certificates of deposit.",
        "label": "Time Deposits",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "TimeDeposits",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsMaturitiesOfTimeDepositsForFuturePeriodsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TimeDepositsLessThan100000": {
     "auth_ref": [
      "r764"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_Deposits",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of time deposit liabilities, including certificates of deposit, in denominations of less than $100,000.",
        "label": "Time Deposits, Less than $100,000",
        "terseLabel": "Certificates of deposit less than $100,000"
       }
      }
     },
     "localname": "TimeDepositsLessThan100000",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureDepositsDepositLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TransfersAndServicingAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Transfers and Servicing [Abstract]"
       }
      }
     },
     "localname": "TransfersAndServicingAbstract",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_TransfersAndServicingOfFinancialAssetsTextBlock": {
     "auth_ref": [
      "r584",
      "r585",
      "r590",
      "r594",
      "r596",
      "r597",
      "r602",
      "r604",
      "r607",
      "r608",
      "r610",
      "r614",
      "r615",
      "r617",
      "r618",
      "r623",
      "r624",
      "r632",
      "r634",
      "r639"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for a transferor's continuing involvement in financial assets that it has transferred in a securitization or asset-backed financing arrangement, the nature of any restrictions on assets reported by an entity in its statement of financial position that relate to a transferred financial asset (including the carrying amounts of such assets), how servicing assets and servicing liabilities are reported, and (for securitization or asset-backed financing arrangements accounted for as sales) when a transferor has continuing involvement with the transferred financial assets and transfers of financial assets accounted for as secured borrowings, how the transfer of financial assets affects an entity's financial position, financial performance, and cash flows.",
        "label": "Transfers and Servicing of Financial Assets [Text Block]",
        "terseLabel": "SERVICING RIGHTS"
       }
      }
     },
     "localname": "TransfersAndServicingOfFinancialAssetsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureServicingRights"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain": {
     "auth_ref": [
      "r247",
      "r251",
      "r264",
      "r265",
      "r266",
      "r364",
      "r370",
      "r509",
      "r584",
      "r585",
      "r586",
      "r587",
      "r588",
      "r589",
      "r591",
      "r592",
      "r593",
      "r598",
      "r599",
      "r600",
      "r601",
      "r605",
      "r609",
      "r619",
      "r620",
      "r621",
      "r622",
      "r626",
      "r627",
      "r628",
      "r629",
      "r630",
      "r631",
      "r632",
      "r633",
      "r636",
      "r637",
      "r638",
      "r765",
      "r766",
      "r767",
      "r768",
      "r769",
      "r770",
      "r771"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Instrument or contract that imposes a contractual obligation to deliver cash or another financial instrument or to exchange other financial instruments on potentially unfavorable terms and conveys a contractual right to receive cash or another financial instrument or to exchange other financial instruments on potentially favorable terms.",
        "label": "Financial Instruments [Domain]"
       }
      }
     },
     "localname": "TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureCommitmentsAndContingenciesCommitmentDetails",
      "http://www.fsbwa.com/role/DisclosureFairValueMeasurementsAvailableForSaleSecuritiesMeasuredAtFairValueOnRecurringBasisDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAllowanceForCreditLossesDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAmortizedCostOfDebtDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesByContractualMaturityDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAvailableForSaleSecuritiesReconciliationDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsInvestmentsWithUnrealizedLossesPolicyDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsChangesInValuationAssumptionsDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsNarrativeDetails",
      "http://www.fsbwa.com/role/DisclosureServicingRightsTables",
      "http://www.fsbwa.com/role/DisclosureServicingRightsValuationAssumptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_TypeOfAdoptionMember": {
     "auth_ref": [
      "r0",
      "r1",
      "r2",
      "r3",
      "r4",
      "r109",
      "r110",
      "r111",
      "r112",
      "r124",
      "r220",
      "r221",
      "r269",
      "r270",
      "r271",
      "r272",
      "r273",
      "r274",
      "r349",
      "r430",
      "r431",
      "r432",
      "r433",
      "r434",
      "r435",
      "r436",
      "r437",
      "r449",
      "r450",
      "r451",
      "r452",
      "r510",
      "r511",
      "r512",
      "r513",
      "r514",
      "r515",
      "r516",
      "r517",
      "r518",
      "r519",
      "r520",
      "r545",
      "r546",
      "r547",
      "r548",
      "r549",
      "r550",
      "r551",
      "r552",
      "r578",
      "r643",
      "r644",
      "r645",
      "r723",
      "r724",
      "r725",
      "r726",
      "r727",
      "r728",
      "r729",
      "r730",
      "r731",
      "r732",
      "r733",
      "r734",
      "r783",
      "r784",
      "r785",
      "r786",
      "r787"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amendment to accounting standards.",
        "label": "Type of Adoption [Domain]"
       }
      }
     },
     "localname": "TypeOfAdoptionMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureBasisOfPresentationAndSummaryOfSignificantAccountingPoliciesAdoptionDetails",
      "http://www.fsbwa.com/role/DisclosureInvestmentsAllowanceForCreditLossesDetails",
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_UnallocatedFinancingReceivablesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financing receivables that have not been allocated to a portfolio segment.",
        "label": "Unallocated Financing Receivables [Member]"
       }
      }
     },
     "localname": "UnallocatedFinancingReceivablesMember",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureLoansReceivableAndAllowanceForCreditLossesLoansAllowanceForLoanLossesByLoanCategoriesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_UnamortizedDebtIssuanceExpense": {
     "auth_ref": [
      "r22"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "fsbw_SubordinatedDebtNetOfUnamortizedDebtIssuanceCosts",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.",
        "label": "Unamortized Debt Issuance Expense",
        "negatedTerseLabel": "Unamortized debt issuance costs"
       }
      }
     },
     "localname": "UnamortizedDebtIssuanceExpense",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UndistributedEarningsLossAvailableToCommonShareholdersBasic": {
     "auth_ref": [
      "r132",
      "r134"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareEarningsPerShareBasicAndDilutesDetailsCalc": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of undistributed earnings (loss) allocated to common stock as if earnings had been distributed. Excludes distributed earnings.",
        "label": "Undistributed Earnings (Loss) Available to Common Shareholders, Basic",
        "totalLabel": "Net income available to common shareholders"
       }
      }
     },
     "localname": "UndistributedEarningsLossAvailableToCommonShareholdersBasic",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareScheduleOfEarningsPerShareBasicAndDilutedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrealizedGainLossOnDerivatives": {
     "auth_ref": [
      "r90"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period.",
        "label": "Unrealized Gain (Loss) on Derivatives",
        "terseLabel": "Change in unrealized gain on fair value and cash flow hedges"
       }
      }
     },
     "localname": "UnrealizedGainLossOnDerivatives",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/StatementConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_VestingAxis": {
     "auth_ref": [
      "r429"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by vesting schedule of award under share-based payment arrangement.",
        "label": "Vesting [Axis]"
       }
      }
     },
     "localname": "VestingAxis",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_VestingDomain": {
     "auth_ref": [
      "r429"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Vesting schedule of award under share-based payment arrangement.",
        "label": "Vesting [Domain]"
       }
      }
     },
     "localname": "VestingDomain",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureStockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding": {
     "auth_ref": [
      "r126",
      "r136"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareEarningsPerShareBasicAndDilutesDetailsCalc": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.",
        "label": "Weighted Average Number of Shares Outstanding, Diluted",
        "totalLabel": "Diluted weighted average common shares outstanding (in shares)"
       }
      }
     },
     "localname": "WeightedAverageNumberOfDilutedSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareScheduleOfEarningsPerShareBasicAndDilutedDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_WeightedAverageNumberOfSharesOutstandingBasic": {
     "auth_ref": [
      "r125",
      "r136"
     ],
     "calculation": {
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareEarningsPerShareBasicAndDilutesDetailsCalc": {
       "order": 1.0,
       "parentTag": "us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding",
       "weight": 1.0
      }
     },
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.",
        "label": "Weighted Average Number of Shares Outstanding, Basic",
        "terseLabel": "Basic weighted average common shares outstanding (in shares)"
       }
      }
     },
     "localname": "WeightedAverageNumberOfSharesOutstandingBasic",
     "nsuri": "http://fasb.org/us-gaap/2021-01-31",
     "presentation": [
      "http://www.fsbwa.com/role/DisclosureEarningsPerShareScheduleOfEarningsPerShareBasicAndDilutedDetails"
     ],
     "xbrltype": "sharesItemType"
    }
   },
   "unitCount": 13
  }
 },
 "std_ref": {
  "r0": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "105",
   "URI": "http://asc.fasb.org/extlink&oid=124434974&loc=SL124442142-165695"
  },
  "r1": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "105",
   "URI": "http://asc.fasb.org/extlink&oid=124434974&loc=SL124442142-165695"
  },
  "r10": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(17))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r100": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(h))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r101": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(m)(1)(iii))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r102": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(m)(2)(ii))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r103": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.12-04(a))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e24072-122690"
  },
  "r104": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "235",
   "URI": "http://asc.fasb.org/topic&trid=2122369"
  },
  "r105": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "23",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124436220&loc=d3e21914-107793"
  },
  "r106": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "24",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124436220&loc=d3e21930-107793"
  },
  "r107": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124436220&loc=d3e21711-107793"
  },
  "r108": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124436220&loc=d3e21728-107793"
  },
  "r109": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(2)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794"
  },
  "r11": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(25))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r110": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(3)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794"
  },
  "r111": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(4)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794"
  },
  "r112": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794"
  },
  "r113": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794"
  },
  "r114": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794"
  },
  "r115": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794"
  },
  "r116": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=SL124452830-107794"
  },
  "r117": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794"
  },
  "r118": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22595-107794"
  },
  "r119": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22644-107794"
  },
  "r12": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(28))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r120": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22644-107794"
  },
  "r121": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22644-107794"
  },
  "r122": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22658-107794"
  },
  "r123": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=124431687&loc=d3e22663-107794"
  },
  "r124": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 11.M.Q2)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=122038215&loc=d3e31137-122693"
  },
  "r125": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1448-109256"
  },
  "r126": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1505-109256"
  },
  "r127": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1252-109256"
  },
  "r128": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1707-109256"
  },
  "r129": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "23",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1757-109256"
  },
  "r13": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(29))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r130": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1500-109256"
  },
  "r131": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "60B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=SL5780133-109256"
  },
  "r132": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "60B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=SL5780133-109256"
  },
  "r133": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "60B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=SL5780133-109256"
  },
  "r134": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "66",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e2814-109256"
  },
  "r135": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125511455&loc=d3e1337-109256"
  },
  "r136": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=124432515&loc=d3e3550-109257"
  },
  "r137": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=124432515&loc=d3e3550-109257"
  },
  "r138": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=124432515&loc=d3e3630-109257"
  },
  "r139": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=109243012&loc=SL65017193-207537"
  },
  "r14": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(3))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r140": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125512782&loc=d3e3842-109258"
  },
  "r141": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "52",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=125512782&loc=d3e4984-109258"
  },
  "r142": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "260",
   "URI": "http://asc.fasb.org/topic&trid=2144383"
  },
  "r143": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "270",
   "URI": "http://asc.fasb.org/extlink&oid=124437754&loc=d3e725-108305"
  },
  "r144": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "270",
   "URI": "http://asc.fasb.org/extlink&oid=124437754&loc=d3e765-108305"
  },
  "r145": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "272",
   "URI": "http://asc.fasb.org/extlink&oid=125520817&loc=d3e70191-108054"
  },
  "r146": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8657-108599"
  },
  "r147": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "18",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8672-108599"
  },
  "r148": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8721-108599"
  },
  "r149": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8721-108599"
  },
  "r15": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(30)(a)(1))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r150": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r151": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r152": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r153": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r154": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r155": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r156": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(g)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r157": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r158": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(j)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r159": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8736-108599"
  },
  "r16": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(30)(a)(3))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r160": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8813-108599"
  },
  "r161": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8813-108599"
  },
  "r162": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8813-108599"
  },
  "r163": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "26",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8844-108599"
  },
  "r164": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "29",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8864-108599"
  },
  "r165": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "29",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8864-108599"
  },
  "r166": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "29",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8864-108599"
  },
  "r167": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "29",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8864-108599"
  },
  "r168": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "29",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8864-108599"
  },
  "r169": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "29",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8864-108599"
  },
  "r17": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(30)(a)(4))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r170": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "30",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599"
  },
  "r171": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "30",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599"
  },
  "r172": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "30",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599"
  },
  "r173": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "30",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599"
  },
  "r174": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "30",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8906-108599"
  },
  "r175": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "31",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8924-108599"
  },
  "r176": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599"
  },
  "r177": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599"
  },
  "r178": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599"
  },
  "r179": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599"
  },
  "r18": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(30))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r180": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599"
  },
  "r181": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8933-108599"
  },
  "r182": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "34",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e8981-108599"
  },
  "r183": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "40",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e9031-108599"
  },
  "r184": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "41",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e9038-108599"
  },
  "r185": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "41",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e9038-108599"
  },
  "r186": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "41",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e9038-108599"
  },
  "r187": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "42",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=123359005&loc=d3e9054-108599"
  },
  "r188": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "280",
   "URI": "http://asc.fasb.org/topic&trid=2134510"
  },
  "r189": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=124259787&loc=d3e4647-111522"
  },
  "r19": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(31))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r190": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=124259787&loc=d3e4428-111522"
  },
  "r191": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=124259787&loc=d3e4437-111522"
  },
  "r192": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524"
  },
  "r193": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524"
  },
  "r194": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524"
  },
  "r195": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(3)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524"
  },
  "r196": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(4)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524"
  },
  "r197": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(g)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524"
  },
  "r198": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524"
  },
  "r199": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524"
  },
  "r2": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "105",
   "URI": "http://asc.fasb.org/extlink&oid=124434974&loc=SL124442142-165695"
  },
  "r20": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(32))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r200": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953550-111524"
  },
  "r201": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(3)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5212-111524"
  },
  "r202": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(4)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5212-111524"
  },
  "r203": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5212-111524"
  },
  "r204": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5212-111524"
  },
  "r205": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5212-111524"
  },
  "r206": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5258-111524"
  },
  "r207": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "29",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953659-111524"
  },
  "r208": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5066-111524"
  },
  "r209": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "35",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL49126937-111524"
  },
  "r21": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.1)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r210": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5074-111524"
  },
  "r211": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5093-111524"
  },
  "r212": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5111-111524"
  },
  "r213": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=d3e5111-111524"
  },
  "r214": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=123577603&loc=SL6953401-111524"
  },
  "r215": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 4.E)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=122038336&loc=d3e74512-122707"
  },
  "r216": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 6.L.1)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=122038336&loc=d3e74567-122707"
  },
  "r217": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/subtopic&trid=2196772"
  },
  "r218": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=6378536&loc=d3e10092-111533"
  },
  "r219": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=84159169&loc=d3e10152-111534"
  },
  "r22": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.17)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r220": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=124402435&loc=SL124402458-218513"
  },
  "r221": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=124402435&loc=SL124402458-218513"
  },
  "r222": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "20",
   "Topic": "310",
   "URI": "http://asc.fasb.org/subtopic&trid=2196816"
  },
  "r223": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(b)(1)(ii)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=121614798&loc=d3e15032-111544"
  },
  "r224": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=124260329&loc=d3e26610-111562"
  },
  "r225": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=124260329&loc=d3e26853-111562"
  },
  "r226": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=124260329&loc=SL6284422-111562"
  },
  "r227": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL6283291-111563"
  },
  "r228": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563"
  },
  "r229": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(aa)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563"
  },
  "r23": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.19-26)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r230": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563"
  },
  "r231": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563"
  },
  "r232": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563"
  },
  "r233": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL121698322-111563"
  },
  "r234": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27198-111563"
  },
  "r235": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27198-111563"
  },
  "r236": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27198-111563"
  },
  "r237": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27198-111563"
  },
  "r238": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27198-111563"
  },
  "r239": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r24": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.20)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r240": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(aa)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r241": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(aaa)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r242": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r243": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r244": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r245": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r246": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)(3)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r247": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27232-111563"
  },
  "r248": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL120269820-111563"
  },
  "r249": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL120269820-111563"
  },
  "r25": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.25)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r250": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL120269820-111563"
  },
  "r251": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL120269820-111563"
  },
  "r252": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL120269825-111563"
  },
  "r253": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL120269825-111563"
  },
  "r254": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5C",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL121698325-111563"
  },
  "r255": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27290-111563"
  },
  "r256": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(2)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27290-111563"
  },
  "r257": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27290-111563"
  },
  "r258": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27337-111563"
  },
  "r259": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27340-111563"
  },
  "r26": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.29-31)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r260": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=SL6284393-111563"
  },
  "r261": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27357-111563"
  },
  "r262": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=123581744&loc=d3e27357-111563"
  },
  "r263": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "320",
   "URI": "http://asc.fasb.org/topic&trid=2196928"
  },
  "r264": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "321",
   "URI": "http://asc.fasb.org/extlink&oid=123583765&loc=SL75117539-209714"
  },
  "r265": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "321",
   "URI": "http://asc.fasb.org/extlink&oid=123583765&loc=SL75117539-209714"
  },
  "r266": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "321",
   "URI": "http://asc.fasb.org/extlink&oid=123583765&loc=SL75117539-209714"
  },
  "r267": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "323",
   "URI": "http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571"
  },
  "r268": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=122640432&loc=SL82887624-210437"
  },
  "r269": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437"
  },
  "r27": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.3,4)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r270": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437"
  },
  "r271": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437"
  },
  "r272": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437"
  },
  "r273": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(e)(3)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437"
  },
  "r274": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(e)(4)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437"
  },
  "r275": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446"
  },
  "r276": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255206&loc=SL120267845-210446"
  },
  "r277": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919244-210447"
  },
  "r278": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447"
  },
  "r279": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447"
  },
  "r28": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.8)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r280": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447"
  },
  "r281": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(e)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447"
  },
  "r282": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(f)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447"
  },
  "r283": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447"
  },
  "r284": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919253-210447"
  },
  "r285": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447"
  },
  "r286": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447"
  },
  "r287": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447"
  },
  "r288": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447"
  },
  "r289": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL120267960-210447"
  },
  "r29": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312"
  },
  "r290": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447"
  },
  "r291": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447"
  },
  "r292": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447"
  },
  "r293": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124255953&loc=SL82919232-210447"
  },
  "r294": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82921830-210448"
  },
  "r295": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82921833-210448"
  },
  "r296": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82921835-210448"
  },
  "r297": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Subparagraph": "(d)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82921835-210448"
  },
  "r298": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Subparagraph": "(d)(2)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82921835-210448"
  },
  "r299": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82921842-210448"
  },
  "r3": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "105",
   "URI": "http://asc.fasb.org/extlink&oid=124434974&loc=SL124442142-165695"
  },
  "r30": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312"
  },
  "r300": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82921842-210448"
  },
  "r301": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "79",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448"
  },
  "r302": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "80",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124267575&loc=SL82922355-210448"
  },
  "r303": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454"
  },
  "r304": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124269663&loc=SL120267853-210455"
  },
  "r305": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124269663&loc=SL120267856-210455"
  },
  "r306": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)(1)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455"
  },
  "r307": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)(2)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455"
  },
  "r308": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455"
  },
  "r309": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124269663&loc=SL82922890-210455"
  },
  "r31": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(2)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312"
  },
  "r310": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124269663&loc=SL82922895-210455"
  },
  "r311": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=124269663&loc=SL82922900-210455"
  },
  "r312": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456"
  },
  "r313": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266"
  },
  "r314": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=99380562&loc=d3e13777-109266"
  },
  "r315": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=120320667&loc=SL49117168-202975"
  },
  "r316": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(e)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267"
  },
  "r317": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267"
  },
  "r318": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=121556970&loc=d3e13854-109267"
  },
  "r319": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274"
  },
  "r32": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(e)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312"
  },
  "r320": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275"
  },
  "r321": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275"
  },
  "r322": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)(1)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275"
  },
  "r323": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)(2)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275"
  },
  "r324": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)(3)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275"
  },
  "r325": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "350",
   "URI": "http://asc.fasb.org/topic&trid=2144416"
  },
  "r326": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229"
  },
  "r327": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230"
  },
  "r328": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230"
  },
  "r329": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "420",
   "URI": "http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869"
  },
  "r33": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312"
  },
  "r330": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "420",
   "URI": "http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869"
  },
  "r331": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 5.P.4(d))",
   "Topic": "420",
   "URI": "http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747"
  },
  "r332": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "440",
   "URI": "http://asc.fasb.org/extlink&oid=123406679&loc=d3e25336-109308"
  },
  "r333": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "440",
   "URI": "http://asc.fasb.org/extlink&oid=123406679&loc=d3e25336-109308"
  },
  "r334": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "440",
   "URI": "http://asc.fasb.org/topic&trid=2144648"
  },
  "r335": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349"
  },
  "r336": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14615-108349"
  },
  "r337": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14394-108349"
  },
  "r338": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349"
  },
  "r339": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349"
  },
  "r34": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=51824906&loc=SL20225877-175312"
  },
  "r340": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14453-108349"
  },
  "r341": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14472-108349"
  },
  "r342": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14557-108349"
  },
  "r343": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "450",
   "URI": "http://asc.fasb.org/topic&trid=2127136"
  },
  "r344": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "15",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=123389529&loc=d3e10037-110241"
  },
  "r345": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=124440162&loc=d3e12021-110248"
  },
  "r346": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=124440162&loc=d3e12053-110248"
  },
  "r347": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(4)",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=124440162&loc=d3e12069-110248"
  },
  "r348": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123465755&loc=d3e1835-112601"
  },
  "r349": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S65",
   "SubTopic": "10",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359872&loc=SL124427846-239511"
  },
  "r35": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313"
  },
  "r350": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-01(a)(4)(i))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756"
  },
  "r351": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-01(a)(4)(ii))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756"
  },
  "r352": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-01(a)(4)(iii)(A))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756"
  },
  "r353": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-01(a)(4)(iii))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756"
  },
  "r354": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-01(a)(4)(iv))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756"
  },
  "r355": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-01(a)(5))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442526-122756"
  },
  "r356": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-02(a)(4)(i))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756"
  },
  "r357": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-02(a)(4)(iii)(A))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756"
  },
  "r358": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-02(a)(4)(iii)(B))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756"
  },
  "r359": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-02(a)(4)(iv))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756"
  },
  "r36": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226016-175313"
  },
  "r360": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.13-02(a)(5))",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=124359900&loc=SL124442552-122756"
  },
  "r361": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611"
  },
  "r362": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(e)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611"
  },
  "r363": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611"
  },
  "r364": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1I",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466505&loc=SL123495371-112611"
  },
  "r365": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "69B",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612"
  },
  "r366": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "69C",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612"
  },
  "r367": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644"
  },
  "r368": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644"
  },
  "r369": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644"
  },
  "r37": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226024-175313"
  },
  "r370": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "18",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=SL123496189-112644"
  },
  "r371": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=123467817&loc=d3e21463-112644"
  },
  "r372": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.3-04)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770"
  },
  "r373": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130551-203045"
  },
  "r374": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045"
  },
  "r375": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045"
  },
  "r376": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045"
  },
  "r377": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045"
  },
  "r378": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045"
  },
  "r379": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(2)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130556-203045"
  },
  "r38": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226038-175313"
  },
  "r380": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130558-203045"
  },
  "r381": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130543-203045"
  },
  "r382": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130545-203045"
  },
  "r383": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123351226&loc=SL49130550-203045"
  },
  "r384": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "91",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123410239&loc=SL49130690-203046-203046"
  },
  "r385": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "91",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=123410239&loc=SL49130690-203046-203046"
  },
  "r386": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "606",
   "URI": "http://asc.fasb.org/topic&trid=49130388"
  },
  "r387": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "710",
   "URI": "http://asc.fasb.org/topic&trid=2127225"
  },
  "r388": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "712",
   "URI": "http://asc.fasb.org/topic&trid=2197446"
  },
  "r389": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(i)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r39": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226049-175313"
  },
  "r390": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(ii)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r391": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(01)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r392": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(02)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r393": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(02)(A)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r394": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(02)(B)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r395": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(02)(C)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r396": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(03)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920"
  },
  "r397": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921"
  },
  "r398": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(a)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450702-114947"
  },
  "r399": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(d)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947"
  },
  "r4": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "105",
   "URI": "http://asc.fasb.org/extlink&oid=124434974&loc=SL124442142-165695"
  },
  "r40": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226052-175313"
  },
  "r400": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(a)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450673-114947"
  },
  "r401": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "80",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=35742348&loc=SL14450788-114948"
  },
  "r402": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "715",
   "URI": "http://asc.fasb.org/topic&trid=2235017"
  },
  "r403": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "35",
   "SubTopic": "10",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=123468992&loc=d3e4534-113899"
  },
  "r404": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901"
  },
  "r405": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901"
  },
  "r406": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901"
  },
  "r407": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r408": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r409": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(3)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r41": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226000-175313"
  },
  "r410": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a),(g)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r411": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r412": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(i)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r413": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(i)-(ii)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r414": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(iii)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r415": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(iv)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r416": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(iv)(3)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r417": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r418": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)(i)-(ii)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r419": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)(iii)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r42": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669646-108580"
  },
  "r420": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)(iii)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r421": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)(iii)(3)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r422": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r423": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r424": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r425": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r426": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)(2)(i)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r427": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)(1)(i)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r428": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(i)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r429": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r43": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669646-108580"
  },
  "r430": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r431": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r432": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r433": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r434": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r435": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(f)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r436": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(f)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r437": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(g)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r438": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 14.D.2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=122041274&loc=d3e301413-122809"
  },
  "r439": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 14.F)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=122041274&loc=d3e301413-122809"
  },
  "r44": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669646-108580"
  },
  "r440": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=122142933&loc=d3e11149-113907"
  },
  "r441": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=122142933&loc=d3e11178-113907"
  },
  "r442": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "40",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=109244457&loc=d3e16649-113920"
  },
  "r443": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "40",
   "Subparagraph": "(a),(b)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=109244457&loc=d3e16545-113920"
  },
  "r444": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "40",
   "Subparagraph": "(c)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=109244661&loc=d3e17540-113929"
  },
  "r445": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "718",
   "URI": "http://asc.fasb.org/topic&trid=2228938"
  },
  "r446": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=123427490&loc=d3e31917-109318"
  },
  "r447": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=123427490&loc=d3e31931-109318"
  },
  "r448": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=121826272&loc=d3e32672-109319"
  },
  "r449": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=123459177&loc=SL121830611-158277"
  },
  "r45": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669646-108580"
  },
  "r450": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=123459177&loc=SL121830611-158277"
  },
  "r451": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(d)(2)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=123459177&loc=SL121830611-158277"
  },
  "r452": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(d)(3)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=123459177&loc=SL121830611-158277"
  },
  "r453": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB TOPIC 6.I.7)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817"
  },
  "r454": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=123586238&loc=d3e38679-109324"
  },
  "r455": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463"
  },
  "r456": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=79982066&loc=d3e1486-128463"
  },
  "r457": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "15",
   "SubTopic": "10",
   "Subparagraph": "(f)(2)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116873149&loc=d3e923-111674"
  },
  "r458": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "19",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=123454820&loc=SL4569616-111683"
  },
  "r459": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116870748&loc=SL6758485-165988"
  },
  "r46": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=d3e637-108580"
  },
  "r460": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116870748&loc=SL6758485-165988"
  },
  "r461": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=d3e5614-111684"
  },
  "r462": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684"
  },
  "r463": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684"
  },
  "r464": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c),(3)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684"
  },
  "r465": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bb)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=123419778&loc=d3e5710-111685"
  },
  "r466": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=123419778&loc=d3e5710-111685"
  },
  "r467": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4J",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=120409616&loc=SL4591551-111686"
  },
  "r468": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4K",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=120409616&loc=SL4591552-111686"
  },
  "r469": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "83",
   "Publisher": "FASB",
   "Section": "15",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125514181&loc=d3e34841-113949"
  },
  "r47": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=d3e640-108580"
  },
  "r470": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=117331979&loc=d3e41228-113958"
  },
  "r471": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5579240-113959"
  },
  "r472": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959"
  },
  "r473": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959"
  },
  "r474": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959"
  },
  "r475": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)(i)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=d3e41620-113959"
  },
  "r476": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)(ii)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=d3e41620-113959"
  },
  "r477": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=d3e41620-113959"
  },
  "r478": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=d3e41638-113959"
  },
  "r479": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5618551-113959"
  },
  "r48": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=d3e681-108580"
  },
  "r480": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(1)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5618551-113959"
  },
  "r481": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(2)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5618551-113959"
  },
  "r482": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a),(c)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959"
  },
  "r483": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959"
  },
  "r484": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959"
  },
  "r485": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4C",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624171-113959"
  },
  "r486": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4C",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624171-113959"
  },
  "r487": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4C",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624171-113959"
  },
  "r488": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4C",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)(2)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624171-113959"
  },
  "r489": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4C",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624171-113959"
  },
  "r49": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669686-108580"
  },
  "r490": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624177-113959"
  },
  "r491": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624177-113959"
  },
  "r492": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624177-113959"
  },
  "r493": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624177-113959"
  },
  "r494": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4E",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624181-113959"
  },
  "r495": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4H",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624258-113959"
  },
  "r496": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4H",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5624258-113959"
  },
  "r497": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4K",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(4)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=SL5708775-113959"
  },
  "r498": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=d3e41641-113959"
  },
  "r499": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=d3e41678-113959"
  },
  "r5": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=d3e1361-107760"
  },
  "r50": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=d3e689-108580"
  },
  "r500": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=125515794&loc=d3e41678-113959"
  },
  "r501": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "182",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123421605&loc=SL5629052-113961"
  },
  "r502": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 5.DD)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=116879480&loc=d3e417888-122833"
  },
  "r503": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=116879480&loc=d3e417888-122833"
  },
  "r504": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=121577181&loc=SL110061172-113977"
  },
  "r505": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=121577181&loc=SL110061190-113977"
  },
  "r506": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "25",
   "Subparagraph": "(a)(1)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=121577467&loc=d3e76258-113986"
  },
  "r507": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "25",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=121577467&loc=d3e76258-113986"
  },
  "r508": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(c)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=121549185&loc=d3e80748-113994"
  },
  "r509": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "40",
   "Subparagraph": "(f)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123477628&loc=d3e90205-114008"
  },
  "r51": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669619-108580"
  },
  "r510": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(a)(1)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r511": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(a)(2)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r512": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(a)(3)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r513": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(b)(1)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r514": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(b)(2)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r515": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(c)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r516": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(d)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r517": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(e)(2)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r518": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(e)(3)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r519": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(e)(4)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r52": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669619-108580"
  },
  "r520": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(f)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011"
  },
  "r521": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "815",
   "URI": "http://asc.fasb.org/topic&trid=2229140"
  },
  "r522": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r523": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r524": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bb)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r525": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bbb)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r526": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bbb)(1)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r527": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bbb)(2)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r528": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r529": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r53": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669619-108580"
  },
  "r530": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1a)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r531": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r532": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r533": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258"
  },
  "r534": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19279-110258"
  },
  "r535": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=d3e19279-110258"
  },
  "r536": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=SL6742756-110258"
  },
  "r537": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=123874694&loc=SL6742756-110258"
  },
  "r538": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "60",
   "SubTopic": "10",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=7493716&loc=d3e21868-110260"
  },
  "r539": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123594809&loc=d3e13220-108610"
  },
  "r54": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669625-108580"
  },
  "r540": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123594938&loc=d3e13279-108611"
  },
  "r541": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611"
  },
  "r542": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123594938&loc=d3e13467-108611"
  },
  "r543": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123594938&loc=d3e13476-108611"
  },
  "r544": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612"
  },
  "r545": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123597120&loc=SL120254526-165497"
  },
  "r546": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123597120&loc=SL120254526-165497"
  },
  "r547": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123597120&loc=SL121967933-165497"
  },
  "r548": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123597120&loc=SL121967933-165497"
  },
  "r549": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123597120&loc=SL121967933-165497"
  },
  "r55": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=SL7669625-108580"
  },
  "r550": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123597120&loc=SL121967933-165497"
  },
  "r551": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123597120&loc=SL122642865-165497"
  },
  "r552": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=123597120&loc=SL122642865-165497"
  },
  "r553": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "230",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=123444420&loc=d3e33268-110906"
  },
  "r554": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32136-110900"
  },
  "r555": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Subparagraph": "(a)",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900"
  },
  "r556": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Subparagraph": "(b)",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900"
  },
  "r557": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Subparagraph": "(c)",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900"
  },
  "r558": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Subparagraph": "(d)",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900"
  },
  "r559": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900"
  },
  "r56": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124509347&loc=d3e557-108580"
  },
  "r560": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=6450520&loc=d3e32583-110901"
  },
  "r561": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391"
  },
  "r562": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=124435984&loc=d3e28555-108399"
  },
  "r563": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "840",
   "URI": "http://asc.fasb.org/extlink&oid=123386454&loc=d3e45280-112737"
  },
  "r564": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123391704&loc=SL77918627-209977"
  },
  "r565": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123391704&loc=SL77918627-209977"
  },
  "r566": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123391704&loc=SL77918643-209977"
  },
  "r567": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(3)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918673-209980"
  },
  "r568": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918673-209980"
  },
  "r569": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918686-209980"
  },
  "r57": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124431353&loc=SL124442407-227067"
  },
  "r570": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918686-209980"
  },
  "r571": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(1)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918686-209980"
  },
  "r572": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(3)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918686-209980"
  },
  "r573": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(4)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918686-209980"
  },
  "r574": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918686-209980"
  },
  "r575": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123408670&loc=SL77918701-209980"
  },
  "r576": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "53",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=123414884&loc=SL77918982-209971"
  },
  "r577": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/subtopic&trid=77888251"
  },
  "r578": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "848",
   "URI": "http://asc.fasb.org/extlink&oid=122150657&loc=SL122150809-237846"
  },
  "r579": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "850",
   "URI": "http://asc.fasb.org/extlink&oid=6457730&loc=d3e39599-107864"
  },
  "r58": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124431353&loc=SL124442411-227067"
  },
  "r580": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "852",
   "URI": "http://asc.fasb.org/extlink&oid=124437977&loc=d3e55792-112764"
  },
  "r581": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "852",
   "URI": "http://asc.fasb.org/extlink&oid=124433192&loc=SL2890621-112765"
  },
  "r582": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "852",
   "URI": "http://asc.fasb.org/extlink&oid=124433192&loc=SL2890621-112765"
  },
  "r583": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "852",
   "URI": "http://asc.fasb.org/extlink&oid=84165509&loc=d3e56426-112766"
  },
  "r584": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(2)(i)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r585": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(2)(ii)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r586": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r587": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r588": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r589": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r59": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124431353&loc=SL124452729-227067"
  },
  "r590": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r591": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r592": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r593": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r594": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(cc)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r595": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719"
  },
  "r596": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(5)(ii)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719"
  },
  "r597": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719"
  },
  "r598": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719"
  },
  "r599": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719"
  },
  "r6": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760"
  },
  "r60": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=124507222&loc=d3e1436-108581"
  },
  "r600": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719"
  },
  "r601": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719"
  },
  "r602": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719"
  },
  "r603": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=SL51823488-111719"
  },
  "r604": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=SL51823488-111719"
  },
  "r605": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=66007379&loc=d3e113888-111728"
  },
  "r606": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(b)(1)(i)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729"
  },
  "r607": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(b)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729"
  },
  "r608": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(c)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729"
  },
  "r609": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=109249958&loc=SL34722452-111729"
  },
  "r61": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(210.5-03(11))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r610": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(c)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=109249958&loc=SL34722452-111729"
  },
  "r611": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "50",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=6469459&loc=d3e122492-111745"
  },
  "r612": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "50",
   "Subparagraph": "(a)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=6469459&loc=d3e122501-111745"
  },
  "r613": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "50",
   "Subparagraph": "(b)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=6469459&loc=d3e122501-111745"
  },
  "r614": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122596-111746"
  },
  "r615": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(b)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122596-111746"
  },
  "r616": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(c)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122596-111746"
  },
  "r617": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(d)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122596-111746"
  },
  "r618": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122625-111746"
  },
  "r619": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122625-111746"
  },
  "r62": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(10))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r620": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122625-111746"
  },
  "r621": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122625-111746"
  },
  "r622": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(4)(i)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122625-111746"
  },
  "r623": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(4)(ii)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122625-111746"
  },
  "r624": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(5)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122625-111746"
  },
  "r625": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r626": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r627": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r628": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r629": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(4)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r63": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(20))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r630": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(5)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r631": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(6)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r632": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(7)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r633": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(b)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r634": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(d)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r635": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(e)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r636": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(e)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r637": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(e)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r638": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(e)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=125521744&loc=d3e122739-111746"
  },
  "r639": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "860",
   "URI": "http://asc.fasb.org/topic&trid=2197590"
  },
  "r64": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(21))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r640": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "910",
   "URI": "http://asc.fasb.org/extlink&oid=123353855&loc=SL119991595-234733"
  },
  "r641": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 11.L)",
   "Topic": "924",
   "URI": "http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856"
  },
  "r642": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "926",
   "URI": "http://asc.fasb.org/extlink&oid=120154696&loc=d3e54445-107959"
  },
  "r643": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "926",
   "URI": "http://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079"
  },
  "r644": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "926",
   "URI": "http://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079"
  },
  "r645": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "926",
   "URI": "http://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079"
  },
  "r646": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "340",
   "Topic": "928",
   "URI": "http://asc.fasb.org/extlink&oid=6473545&loc=d3e61844-108004"
  },
  "r647": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "20",
   "Topic": "940",
   "URI": "http://asc.fasb.org/extlink&oid=123384075&loc=d3e41242-110953"
  },
  "r648": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "320",
   "Topic": "940",
   "URI": "http://asc.fasb.org/subtopic&trid=2176304"
  },
  "r649": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "210",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117340910&loc=d3e59706-112781"
  },
  "r65": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(24))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r650": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(1))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r651": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(10)(1))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r652": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(10))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r653": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(11))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r654": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(23))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r655": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(6))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r656": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(7)(2))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r657": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.10(4))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r658": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.12)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r659": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.13,16)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r66": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(25))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r660": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.15)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r661": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.17)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r662": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.2)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r663": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(13))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r664": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(15))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r665": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(22))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r666": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(23))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r667": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(26))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r668": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(27))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r669": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.1)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r67": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(b)(4))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r670": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.1-5)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r671": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.10)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r672": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.11)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r673": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.12)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r674": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.13(h))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r675": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.13)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r676": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.14(b))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r677": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.14(d))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r678": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.14)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r679": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.6)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r68": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.4)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r680": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.8)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r681": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.9)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r682": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "235",
   "Subparagraph": "(SX 210.9-05(b)(2))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399901&loc=d3e537907-122884"
  },
  "r683": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Subparagraph": "(c)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=d3e62586-112803"
  },
  "r684": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=d3e62586-112803"
  },
  "r685": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Subparagraph": "(a)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=SL120269850-112803"
  },
  "r686": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Subparagraph": "(b)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=SL120269850-112803"
  },
  "r687": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Subparagraph": "(c)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=SL120269850-112803"
  },
  "r688": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Subparagraph": "(d)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=SL120269850-112803"
  },
  "r689": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599081&loc=SL120269850-112803"
  },
  "r69": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.6)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r690": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "320",
   "Topic": "942",
   "URI": "http://asc.fasb.org/subtopic&trid=2209399"
  },
  "r691": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "325",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=123599499&loc=d3e63345-112809"
  },
  "r692": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "360",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=124429447&loc=SL124453093-239630"
  },
  "r693": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "405",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=116652737&loc=d3e64164-112818"
  },
  "r694": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Subparagraph": "(a)(1)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826"
  },
  "r695": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Subparagraph": "(a)(2)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826"
  },
  "r696": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Subparagraph": "(b)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826"
  },
  "r697": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Subparagraph": "(c)(1)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826"
  },
  "r698": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Subparagraph": "(c)(2)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826"
  },
  "r699": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Subparagraph": "(e)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826"
  },
  "r7": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=124098289&loc=d3e6676-107765"
  },
  "r70": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.7(a),(b))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227"
  },
  "r700": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958569-112826"
  },
  "r701": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958570-112826"
  },
  "r702": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1D",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958573-112826"
  },
  "r703": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1F",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "505",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=117337116&loc=SL5958575-112826"
  },
  "r704": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(10))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r705": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(12))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r706": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(23)(a)(3))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r707": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(23)(a)(4))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r708": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(25))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r709": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(8))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r71": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3151-108585"
  },
  "r710": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03.(a),19)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r711": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(18))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r712": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(19))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r713": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(22))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r714": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(23))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r715": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(8))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r716": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(9))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r717": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04.3(a))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r718": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4H",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "40",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=116884468&loc=SL65671331-158438"
  },
  "r719": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "40",
   "Subparagraph": "(d)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124506351&loc=SL117782755-158439"
  },
  "r72": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3179-108585"
  },
  "r720": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13H",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "40",
   "Subparagraph": "(a)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124504033&loc=SL117783719-158441"
  },
  "r721": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13H",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "40",
   "Subparagraph": "(b)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124504033&loc=SL117783719-158441"
  },
  "r722": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "29F",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "40",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124504033&loc=SL117819544-158441"
  },
  "r723": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(a)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r724": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(b)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r725": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(e)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r726": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(f)(1)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r727": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(f)(2)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r728": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(g)(1)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r729": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(g)(2)(i)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r73": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3179-108585"
  },
  "r730": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(g)(2)(ii)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r731": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(g)(2)(iii)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r732": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(g)(2)(iv)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r733": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(h)(1)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r734": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(h)(2)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641"
  },
  "r735": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(e)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=124508989&loc=d3e19393-158473"
  },
  "r736": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=66023616&loc=SL35737432-115832"
  },
  "r737": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "220",
   "Subparagraph": "(k)",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=124433917&loc=SL114874205-224268"
  },
  "r738": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.6-07.2(a),(b),(c),(d))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=120401555&loc=SL114874292-224272"
  },
  "r739": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-12B(Column B)(Footnote 6))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=122147990&loc=d3e611197-123010"
  },
  "r74": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3213-108585"
  },
  "r740": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-12B(Column C)(Footnote 6))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=122147990&loc=d3e611197-123010"
  },
  "r741": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-12B(Column D)(Footnote 6))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=122147990&loc=d3e611197-123010"
  },
  "r742": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "320",
   "Topic": "946",
   "URI": "http://asc.fasb.org/subtopic&trid=2324412"
  },
  "r743": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "948",
   "URI": "http://asc.fasb.org/extlink&oid=6490092&loc=d3e47080-110998"
  },
  "r744": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "948",
   "URI": "http://asc.fasb.org/extlink&oid=6490092&loc=d3e47304-110998"
  },
  "r745": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "310",
   "Subparagraph": "(SX 210.12-29(Footnote 4))",
   "Topic": "948",
   "URI": "http://asc.fasb.org/extlink&oid=120402547&loc=d3e617274-123014"
  },
  "r746": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "440",
   "Subparagraph": "(a)",
   "Topic": "954",
   "URI": "http://asc.fasb.org/extlink&oid=6491277&loc=d3e6429-115629"
  },
  "r747": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Column B))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r748": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Column C))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r749": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Column D))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r75": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3213-108585"
  },
  "r750": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Column E))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r751": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Column F))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r752": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Column G))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r753": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Column H))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r754": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Column I))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r755": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Footnote 2))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r756": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "360",
   "Subparagraph": "(SX 210.12-28(Footnote 4))",
   "Topic": "970",
   "URI": "http://asc.fasb.org/extlink&oid=120402810&loc=d3e638233-123024"
  },
  "r757": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "310",
   "Subparagraph": "(c)",
   "Topic": "976",
   "URI": "http://asc.fasb.org/extlink&oid=6497875&loc=d3e22274-108663"
  },
  "r758": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "310",
   "Subparagraph": "(b)",
   "Topic": "978",
   "URI": "http://asc.fasb.org/extlink&oid=123360121&loc=d3e27327-108691"
  },
  "r759": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b"
  },
  "r76": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585"
  },
  "r760": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b-2"
  },
  "r761": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "d1-1"
  },
  "r762": {
   "Name": "Form 10-Q",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "308",
   "Subsection": "a"
  },
  "r763": {
   "Name": "Forms 10-K, 10-Q, 20-F",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "13",
   "Subsection": "a-1"
  },
  "r764": {
   "Name": "Industry Guide",
   "Number": "3",
   "Paragraph": "D-E",
   "Publisher": "SEC",
   "Section": "V"
  },
  "r765": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1402"
  },
  "r766": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(b)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(1)"
  },
  "r767": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(b)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(2)"
  },
  "r768": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(b)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(3)"
  },
  "r769": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(c)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(2)(i)"
  },
  "r77": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585"
  },
  "r770": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(c)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(2)(ii)"
  },
  "r771": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(c)",
   "Publisher": "SEC",
   "Section": "1402",
   "Subparagraph": "(2)(iii)"
  },
  "r772": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(b)",
   "Publisher": "SEC",
   "Section": "1403"
  },
  "r773": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1404"
  },
  "r774": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(b)",
   "Publisher": "SEC",
   "Section": "1404"
  },
  "r775": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1405",
   "Subparagraph": "(1)"
  },
  "r776": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1405",
   "Subparagraph": "(2)"
  },
  "r777": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1405",
   "Subparagraph": "(3)"
  },
  "r778": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(a)",
   "Publisher": "SEC",
   "Section": "1405",
   "Subparagraph": "(4)"
  },
  "r779": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(c)",
   "Publisher": "SEC",
   "Section": "1405"
  },
  "r78": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585"
  },
  "r780": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Publisher": "SEC",
   "Section": "1406"
  },
  "r781": {
   "Name": "Regulation S-K (SK)",
   "Number": "229",
   "Paragraph": "(e)",
   "Publisher": "SEC",
   "Section": "1406"
  },
  "r782": {
   "Name": "Regulation S-T",
   "Number": "232",
   "Publisher": "SEC",
   "Section": "405"
  },
  "r783": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "848"
  },
  "r784": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "848"
  },
  "r785": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)(2)",
   "Topic": "848"
  },
  "r786": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)(3)(iii)(01)",
   "Topic": "848"
  },
  "r787": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)(3)(iii)(03)",
   "Topic": "848"
  },
  "r79": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3337-108585"
  },
  "r8": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(13))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r80": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3367-108585"
  },
  "r81": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3000-108585"
  },
  "r82": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3461-108585"
  },
  "r83": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21C",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=SL94080552-108585"
  },
  "r84": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "24",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3521-108585"
  },
  "r85": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3536-108585"
  },
  "r86": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3536-108585"
  },
  "r87": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(g)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3536-108585"
  },
  "r88": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3536-108585"
  },
  "r89": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585"
  },
  "r9": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(14))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r90": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585"
  },
  "r91": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585"
  },
  "r92": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123570139&loc=d3e3044-108585"
  },
  "r93": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123431023&loc=d3e4297-108586"
  },
  "r94": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123431023&loc=d3e4304-108586"
  },
  "r95": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123431023&loc=d3e4313-108586"
  },
  "r96": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123431023&loc=d3e4332-108586"
  },
  "r97": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=123431023&loc=SL98516268-108586"
  },
  "r98": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=123372394&loc=d3e18823-107790"
  },
  "r99": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(g)(1)(ii))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  }
 },
 "version": "2.1"
}
