{
 "instance": {
  "ffiv-20200930.htm": {
   "axisCustom": 2,
   "axisStandard": 27,
   "contextCount": 280,
   "dts": {
    "calculationLink": {
     "local": [
      "ffiv-20200930_cal.xml"
     ]
    },
    "definitionLink": {
     "local": [
      "ffiv-20200930_def.xml"
     ],
     "remote": [
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-eedm-def-2019-01-31.xml",
      "http://xbrl.fasb.org/srt/2019/elts/srt-eedm1-def-2019-01-31.xml"
     ]
    },
    "inline": {
     "local": [
      "ffiv-20200930.htm"
     ]
    },
    "labelLink": {
     "local": [
      "ffiv-20200930_lab.xml"
     ],
     "remote": [
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-doc-2019-01-31.xml",
      "https://xbrl.sec.gov/dei/2019/dei-doc-2019-01-31.xml"
     ]
    },
    "presentationLink": {
     "local": [
      "ffiv-20200930_pre.xml"
     ]
    },
    "referenceLink": {
     "remote": [
      "https://xbrl.sec.gov/dei/2019/dei-ref-2019-01-31.xml",
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-ref-2019-01-31.xml"
     ]
    },
    "schema": {
     "local": [
      "ffiv-20200930.xsd"
     ],
     "remote": [
      "http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd",
      "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/dtr/type/numeric-2009-12-16.xsd",
      "http://www.xbrl.org/dtr/type/nonNumeric-2009-12-16.xsd",
      "http://www.xbrl.org/2005/xbrldt-2005.xsd",
      "http://www.xbrl.org/2006/ref-2006-02-27.xsd",
      "http://xbrl.fasb.org/srt/2019/elts/srt-types-2019-01-31.xsd",
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-2019-01-31.xsd",
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-roles-2019-01-31.xsd",
      "http://xbrl.fasb.org/srt/2019/elts/srt-roles-2019-01-31.xsd",
      "https://xbrl.sec.gov/country/2017/country-2017-01-31.xsd",
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-types-2019-01-31.xsd",
      "https://xbrl.sec.gov/dei/2019/dei-2019-01-31.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",
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-parts-codification-2019-01-31.xsd",
      "http://www.xbrl.org/lrr/role/deprecated-2009-12-16.xsd"
     ]
    }
   },
   "elementCount": 751,
   "entityCount": 1,
   "hidden": {
    "http://fasb.org/us-gaap/2019-01-31": 8,
    "http://xbrl.sec.gov/dei/2019-01-31": 5,
    "total": 13
   },
   "keyCustom": 53,
   "keyStandard": 512,
   "memberCustom": 40,
   "memberStandard": 45,
   "nsprefix": "ffiv",
   "nsuri": "http://www.f5.com/20200930",
   "report": {
    "R1": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:DocumentType",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "document",
     "isDefault": "true",
     "longName": "0001001 - Document - Cover Page",
     "role": "http://www.f5.com/role/CoverPage",
     "shortName": "Cover Page",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:DocumentType",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R10": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RevenueFromContractWithCustomerTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2108102 - Disclosure - Revenue from Contracts with Customers",
     "role": "http://www.f5.com/role/RevenuefromContractswithCustomers",
     "shortName": "Revenue from Contracts with Customers",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RevenueFromContractWithCustomerTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R11": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BusinessCombinationDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2114103 - Disclosure - Business Combinations",
     "role": "http://www.f5.com/role/BusinessCombinations",
     "shortName": "Business Combinations",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BusinessCombinationDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R12": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2118104 - Disclosure - Fair Value Measurements",
     "role": "http://www.f5.com/role/FairValueMeasurements",
     "shortName": "Fair Value Measurements",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R13": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2122105 - Disclosure - Short-Term And Long-Term Investments",
     "role": "http://www.f5.com/role/ShortTermAndLongTermInvestments",
     "shortName": "Short-Term And Long-Term Investments",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R14": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SupplementalBalanceSheetDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2127106 - Disclosure - Balance Sheet Details",
     "role": "http://www.f5.com/role/BalanceSheetDetails",
     "shortName": "Balance Sheet Details",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SupplementalBalanceSheetDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R15": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DebtDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2140107 - Disclosure - Debt Facilities",
     "role": "http://www.f5.com/role/DebtFacilities",
     "shortName": "Debt Facilities",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DebtDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R16": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LesseeOperatingLeasesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2144108 - Disclosure - Leases",
     "role": "http://www.f5.com/role/Leases",
     "shortName": "Leases",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LesseeOperatingLeasesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R17": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:IncomeTaxDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2151109 - Disclosure - Income Taxes",
     "role": "http://www.f5.com/role/IncomeTaxes",
     "shortName": "Income Taxes",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:IncomeTaxDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R18": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:StockholdersEquityNoteDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2159110 - Disclosure - Shareholders' Equity",
     "role": "http://www.f5.com/role/ShareholdersEquity",
     "shortName": "Shareholders' Equity",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:StockholdersEquityNoteDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R19": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2163111 - Disclosure - Stock-Based Compensation",
     "role": "http://www.f5.com/role/StockBasedCompensation",
     "shortName": "Stock-Based Compensation",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R2": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CashAndCashEquivalentsAtCarryingValue",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "1001002 - Statement - Consolidated Balance Sheets",
     "role": "http://www.f5.com/role/ConsolidatedBalanceSheets",
     "shortName": "Consolidated Balance Sheets",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:ShortTermInvestments",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R20": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EarningsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2173112 - Disclosure - Net Income Per Share",
     "role": "http://www.f5.com/role/NetIncomePerShare",
     "shortName": "Net Income Per Share",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EarningsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R21": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2176113 - Disclosure - Commitments And Contingencies",
     "role": "http://www.f5.com/role/CommitmentsAndContingencies",
     "shortName": "Commitments And Contingencies",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R22": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RestructuringAndRelatedActivitiesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2178114 - Disclosure - Restructuring Charges",
     "role": "http://www.f5.com/role/RestructuringCharges",
     "shortName": "Restructuring Charges",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RestructuringAndRelatedActivitiesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R23": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CompensationAndEmployeeBenefitPlansOtherThanShareBasedCompensationTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2182115 - Disclosure - Employee Benefit Plans",
     "role": "http://www.f5.com/role/EmployeeBenefitPlans",
     "shortName": "Employee Benefit Plans",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CompensationAndEmployeeBenefitPlansOtherThanShareBasedCompensationTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R24": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SegmentReportingDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2184116 - Disclosure - Segment Information",
     "role": "http://www.f5.com/role/SegmentInformation",
     "shortName": "Segment Information",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SegmentReportingDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R25": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:QuarterlyFinancialInformationTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2187117 - Disclosure - Quarterly Results Of Operations (Unaudited)",
     "role": "http://www.f5.com/role/QuarterlyResultsOfOperationsUnaudited",
     "shortName": "Quarterly Results Of Operations (Unaudited)",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:QuarterlyFinancialInformationTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R26": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BasisOfAccountingPolicyPolicyTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2202201 - Disclosure - Summary Of Significant Accounting Policies (Policy)",
     "role": "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy",
     "shortName": "Summary Of Significant Accounting Policies (Policy)",
     "subGroupType": "policies",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BasisOfAccountingPolicyPolicyTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R27": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfInventoryCurrentTableTextBlock",
      "reportCount": 1,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2303301 - Disclosure - Accounting Policies (Tables)",
     "role": "http://www.f5.com/role/AccountingPoliciesTables",
     "shortName": "Accounting Policies (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": null
    },
    "R28": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CapitalizedContractCostTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2309302 - Disclosure - Revenue from Contracts with Customers (Tables)",
     "role": "http://www.f5.com/role/RevenuefromContractswithCustomersTables",
     "shortName": "Revenue from Contracts with Customers (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CapitalizedContractCostTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R29": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2315303 - Disclosure - Business Combinations (Tables)",
     "role": "http://www.f5.com/role/BusinessCombinationsTables",
     "shortName": "Business Combinations (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R3": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "1002003 - Statement - Consolidated Balance Sheets (Parenthetical)",
     "role": "http://www.f5.com/role/ConsolidatedBalanceSheetsParenthetical",
     "shortName": "Consolidated Balance Sheets (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R30": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueAssetsMeasuredOnRecurringBasisTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2319304 - Disclosure - Fair Value Measurements (Tables)",
     "role": "http://www.f5.com/role/FairValueMeasurementsTables",
     "shortName": "Fair Value Measurements (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueAssetsMeasuredOnRecurringBasisTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R31": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2323305 - Disclosure - Short-Term And Long-Term Investments (Tables)",
     "role": "http://www.f5.com/role/ShortTermAndLongTermInvestmentsTables",
     "shortName": "Short-Term And Long-Term Investments (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R32": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:ScheduleOfCashAndCashEquivalentsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfCashAndCashEquivalentsTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2328306 - Disclosure - Balance Sheet Details (Tables)",
     "role": "http://www.f5.com/role/BalanceSheetDetailsTables",
     "shortName": "Balance Sheet Details (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:ScheduleOfCashAndCashEquivalentsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfCashAndCashEquivalentsTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R33": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfMaturitiesOfLongTermDebtTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2341307 - Disclosure - Debt Facilities (Tables)",
     "role": "http://www.f5.com/role/DebtFacilitiesTables",
     "shortName": "Debt Facilities (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfMaturitiesOfLongTermDebtTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R34": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LeaseCostTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2345308 - Disclosure - Leases (Tables)",
     "role": "http://www.f5.com/role/LeasesTables",
     "shortName": "Leases (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LeaseCostTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R35": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2352309 - Disclosure - Income Taxes (Tables)",
     "role": "http://www.f5.com/role/IncomeTaxesTables",
     "shortName": "Income Taxes (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R36": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ibb4a1d6b0d2b49fd9fa3e2b3da6a867e_D20200701-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfTreasuryStockByClassTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2360310 - Disclosure - Shareholders' Equity (Tables)",
     "role": "http://www.f5.com/role/ShareholdersEquityTables",
     "shortName": "Shareholders' Equity (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ibb4a1d6b0d2b49fd9fa3e2b3da6a867e_D20200701-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfTreasuryStockByClassTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R37": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfShareBasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2364311 - Disclosure - Stock-Based Compensation (Tables)",
     "role": "http://www.f5.com/role/StockBasedCompensationTables",
     "shortName": "Stock-Based Compensation (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfShareBasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R38": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
      "reportCount": 1,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2374312 - Disclosure - Net Income Per Share (Tables)",
     "role": "http://www.f5.com/role/NetIncomePerShareTables",
     "shortName": "Net Income Per Share (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": null
    },
    "R39": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfRestructuringAndRelatedCostsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2379313 - Disclosure - Restructuring Charges (Tables)",
     "role": "http://www.f5.com/role/RestructuringChargesTables",
     "shortName": "Restructuring Charges (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfRestructuringAndRelatedCostsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R4": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfQuarterlyFinancialInformationTableTextBlock",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ibb4a1d6b0d2b49fd9fa3e2b3da6a867e_D20200701-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "1003004 - Statement - Consolidated Income Statements",
     "role": "http://www.f5.com/role/ConsolidatedIncomeStatements",
     "shortName": "Consolidated Income Statements",
     "subGroupType": "",
     "uniqueAnchor": null
    },
    "R40": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfRevenueFromExternalCustomersAttributedToForeignCountriesByGeographicAreaTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2385314 - Disclosure - Segment Information (Tables)",
     "role": "http://www.f5.com/role/SegmentInformationTables",
     "shortName": "Segment Information (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfRevenueFromExternalCustomersAttributedToForeignCountriesByGeographicAreaTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R41": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfQuarterlyFinancialInformationTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2388315 - Disclosure - Quarterly Results Of Operations (Unaudited) (Tables)",
     "role": "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedTables",
     "shortName": "Quarterly Results Of Operations (Unaudited) (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfQuarterlyFinancialInformationTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R42": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "us-gaap:SegmentReportingPolicyPolicyTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NumberOfReportableSegments",
      "reportCount": 1,
      "unitRef": "segment",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2404401 - Disclosure - Summary Of Significant Accounting Policies - Narrative (Details)",
     "role": "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails",
     "shortName": "Summary Of Significant Accounting Policies - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "us-gaap:AdvertisingCostsPolicyTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:AdvertisingExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R43": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfInventoryCurrentTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InventoryFinishedGoods",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2405402 - Disclosure - Summary Of Significant Accounting Policies - Schedule Of Inventories (Details)",
     "role": "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfInventoriesDetails",
     "shortName": "Summary Of Significant Accounting Policies - Schedule Of Inventories (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R44": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:MachineryAndEquipmentGross",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2406403 - Disclosure - Summary Of Significant Accounting Policies - Property And Equipment (Details)",
     "role": "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails",
     "shortName": "Summary Of Significant Accounting Policies - Property And Equipment (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R45": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfQuarterlyFinancialInformationTableTextBlock",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ibb4a1d6b0d2b49fd9fa3e2b3da6a867e_D20200701-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2407404 - Disclosure - Summary Of Significant Accounting Policies - Schedule Of Computation Of Basic And Diluted Net Income Per Share (Details)",
     "role": "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfComputationOfBasicAndDilutedNetIncomePerShareDetails",
     "shortName": "Summary Of Significant Accounting Policies - Schedule Of Computation Of Basic And Diluted Net Income Per Share (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R46": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:CapitalizedContractCostTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic500f4566a87409ab441e8ac4201f434_I20190930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CapitalizedContractCostNet",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2410405 - Disclosure - Revenue from Contracts with Customers - Capitalized Contract Acquisition Costs (Details)",
     "role": "http://www.f5.com/role/RevenuefromContractswithCustomersCapitalizedContractAcquisitionCostsDetails",
     "shortName": "Revenue from Contracts with Customers - Capitalized Contract Acquisition Costs (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:CapitalizedContractCostTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ie123912a893e402288422078cbe23525_I20180930",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:CapitalizedContractCostNet",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R47": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:CapitalizedContractCostTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CapitalizedContractCostAmortization",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2411406 - Disclosure - Revenue from Contracts with Customers - Narrative (Details)",
     "role": "http://www.f5.com/role/RevenuefromContractswithCustomersNarrativeDetails",
     "shortName": "Revenue from Contracts with Customers - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "INF",
      "lang": "en-US",
      "name": "us-gaap:CapitalizedContractCostImpairmentLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R48": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ContractWithCustomerAssetAndLiabilityTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic500f4566a87409ab441e8ac4201f434_I20190930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ContractWithCustomerAssetNet",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2412407 - Disclosure - Revenue from Contracts with Customers - Contract Assets and Liabilities (Details)",
     "role": "http://www.f5.com/role/RevenuefromContractswithCustomersContractAssetsandLiabilitiesDetails",
     "shortName": "Revenue from Contracts with Customers - Contract Assets and Liabilities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ContractWithCustomerAssetAndLiabilityTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ie123912a893e402288422078cbe23525_I20180930",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:ContractWithCustomerAssetNet",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R49": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-8",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RevenueRemainingPerformanceObligation",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2413408 - Disclosure - Revenue from Contracts with Customers - Remaining Performance Obligations. (Details)",
     "role": "http://www.f5.com/role/RevenuefromContractswithCustomersRemainingPerformanceObligationsDetails",
     "shortName": "Revenue from Contracts with Customers - Remaining Performance Obligations. (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-8",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RevenueRemainingPerformanceObligation",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R5": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "1004005 - Statement - Consolidated Statements of Comprehensive Income Statement",
     "role": "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement",
     "shortName": "Consolidated Statements of Comprehensive Income Statement",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R50": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfGoodwillTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:GoodwillOtherIncreaseDecrease",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2416409 - Disclosure - Business Combinations - Narrative (Details)",
     "role": "http://www.f5.com/role/BusinessCombinationsNarrativeDetails",
     "shortName": "Business Combinations - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i5e657d86076f4770bb635d3e6f29481c_I20200124",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:BusinessAcquisitionCostOfAcquiredEntityTransactionCosts",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R51": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Goodwill",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2417410 - Disclosure - Business Combinations - Purchase Price Allocation (Details)",
     "role": "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails",
     "shortName": "Business Combinations - Purchase Price Allocation (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i5e657d86076f4770bb635d3e6f29481c_I20200124",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R52": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:FairValueAssetsMeasuredOnRecurringBasisTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CashAndCashEquivalentsFairValueDisclosure",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2420411 - Disclosure - Fair Value Measurements - Schedule Of Financial Assets Measured At Fair Value On A Recurring Basis (Details)",
     "role": "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails",
     "shortName": "Fair Value Measurements - Schedule Of Financial Assets Measured At Fair Value On A Recurring Basis (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:FairValueAssetsMeasuredOnRecurringBasisTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CashAndCashEquivalentsFairValueDisclosure",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R53": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OperatingLeaseImpairmentLoss",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2421412 - Disclosure - Fair Value Measurements - Impairment of Assets Measured at Fair Value on a Nonrecurring Basis (Details)",
     "role": "http://www.f5.com/role/FairValueMeasurementsImpairmentofAssetsMeasuredatFairValueonaNonrecurringBasisDetails",
     "shortName": "Fair Value Measurements - Impairment of Assets Measured at Fair Value on a Nonrecurring Basis (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R54": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AvailableForSaleSecuritiesAmortizedCost",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2424413 - Disclosure - Short-Term And Long-Term Investments - Schedule Of Short-Term And Long-Term Investments (Details)",
     "role": "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails",
     "shortName": "Short-Term And Long-Term Investments - Schedule Of Short-Term And Long-Term Investments (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AvailableForSaleSecuritiesAmortizedCost",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R55": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2425414 - Disclosure - Short-Term And Long-Term Investments - Schedule Of Investments That Have Been In A Continuous Unrealized Loss Position (Details)",
     "role": "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails",
     "shortName": "Short-Term And Long-Term Investments - Schedule Of Investments That Have Been In A Continuous Unrealized Loss Position (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R56": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentIncomeInterest",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2426415 - Disclosure - Short-Term And Long-Term Investments - Narrative (Details)",
     "role": "http://www.f5.com/role/ShortTermAndLongTermInvestmentsNarrativeDetails",
     "shortName": "Short-Term And Long-Term Investments - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentIncomeInterest",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R57": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DepreciationDepletionAndAmortization",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2429416 - Disclosure - Balance Sheet Details - Narrative (Details)",
     "role": "http://www.f5.com/role/BalanceSheetDetailsNarrativeDetails",
     "shortName": "Balance Sheet Details - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "iba591be76dc1476e8307d35937b69997_D20191001-20200930",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:DepreciationDepletionAndAmortization",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R58": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CashAndCashEquivalentsAtCarryingValue",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2430417 - Disclosure - Balance Sheet Details - Cash, Cash Equivalents and Restricted Cash (Details)",
     "role": "http://www.f5.com/role/BalanceSheetDetailsCashCashEquivalentsandRestrictedCashDetails",
     "shortName": "Balance Sheet Details - Cash, Cash Equivalents and Restricted Cash (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfCashAndCashEquivalentsTableTextBlock",
       "us-gaap:ScheduleOfCashAndCashEquivalentsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:RestrictedCash",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R59": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfInventoryCurrentTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InventoryFinishedGoods",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2431418 - Disclosure - Balance Sheet Details - Inventories (Details)",
     "role": "http://www.f5.com/role/BalanceSheetDetailsInventoriesDetails",
     "shortName": "Balance Sheet Details - Inventories (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R6": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "1005006 - Statement - Consolidated Statements of Comprehensive Income (Parentheticals)",
     "role": "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeParentheticals",
     "shortName": "Consolidated Statements of Comprehensive Income (Parentheticals)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R60": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfOtherCurrentAssetsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ContractWithCustomerAssetNetCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2432419 - Disclosure - Balance Sheet Details - Other Current Assets (Details)",
     "role": "http://www.f5.com/role/BalanceSheetDetailsOtherCurrentAssetsDetails",
     "shortName": "Balance Sheet Details - Other Current Assets (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfOtherCurrentAssetsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ContractWithCustomerAssetNetCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R61": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ix:continuation",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:MachineryAndEquipmentGross",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2433420 - Disclosure - Balance Sheet Details - Property and Equipment (Details)",
     "role": "http://www.f5.com/role/BalanceSheetDetailsPropertyandEquipmentDetails",
     "shortName": "Balance Sheet Details - Property and Equipment (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R62": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic500f4566a87409ab441e8ac4201f434_I20190930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:Goodwill",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2434421 - Disclosure - Balance Sheet Details - Goodwill (Details)",
     "role": "http://www.f5.com/role/BalanceSheetDetailsGoodwillDetails",
     "shortName": "Balance Sheet Details - Goodwill (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfGoodwillTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:GoodwillAcquiredDuringPeriod",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R63": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FiniteLivedIntangibleAssetsNet",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2435422 - Disclosure - Balance Sheet Details - Other Assets (Details)",
     "role": "http://www.f5.com/role/BalanceSheetDetailsOtherAssetsDetails",
     "shortName": "Balance Sheet Details - Other Assets (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfOtherAssetsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:ContractWithCustomerAssetNetNoncurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R64": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FiniteLivedIntangibleAssetsGross",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2436423 - Disclosure - Balance Sheet Details - Intangible Assets (Details)",
     "role": "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails",
     "shortName": "Balance Sheet Details - Intangible Assets (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FiniteLivedIntangibleAssetsGross",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R65": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2437424 - Disclosure - Balance Sheet Details - Estimated Amortization Expense For Intangible Assets (Details)",
     "role": "http://www.f5.com/role/BalanceSheetDetailsEstimatedAmortizationExpenseForIntangibleAssetsDetails",
     "shortName": "Balance Sheet Details - Estimated Amortization Expense For Intangible Assets (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R66": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfAccruedLiabilitiesTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EmployeeRelatedLiabilitiesCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2438425 - Disclosure - Balance Sheet Details - Accrued Liabilities (Details)",
     "role": "http://www.f5.com/role/BalanceSheetDetailsAccruedLiabilitiesDetails",
     "shortName": "Balance Sheet Details - Accrued Liabilities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfAccruedLiabilitiesTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EmployeeRelatedLiabilitiesCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R67": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:OtherNoncurrentLiabilitiesTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DeferredRentCreditNoncurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2439426 - Disclosure - Balance Sheet Details - Other Long-term Liabilities (Details)",
     "role": "http://www.f5.com/role/BalanceSheetDetailsOtherLongtermLiabilitiesDetails",
     "shortName": "Balance Sheet Details - Other Long-term Liabilities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:OtherNoncurrentLiabilitiesTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DeferredRentCreditNoncurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R68": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i67923d3ea6844531a94671dc17c86993_I20200124",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2442427 - Disclosure - Debt Facilities - Narrative (Details)",
     "role": "http://www.f5.com/role/DebtFacilitiesNarrativeDetails",
     "shortName": "Debt Facilities - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i67923d3ea6844531a94671dc17c86993_I20200124",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R69": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i794cf6c4874d4487907205bb751e2b68_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2443428 - Disclosure - Debt Facilities - Long-term Debt Maturities (Details)",
     "role": "http://www.f5.com/role/DebtFacilitiesLongtermDebtMaturitiesDetails",
     "shortName": "Debt Facilities - Long-term Debt Maturities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i794cf6c4874d4487907205bb751e2b68_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R7": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ia625706bfeab402187cd214283c05d45_I20170930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommonStockSharesOutstanding",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "1006007 - Statement - Consolidated Statement Of Shareholders' Equity",
     "role": "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity",
     "shortName": "Consolidated Statement Of Shareholders' Equity",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ia625706bfeab402187cd214283c05d45_I20170930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommonStockSharesOutstanding",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R70": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ffiv:AssetsAndLiabilitiesLesseeTableTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OperatingLeaseRightOfUseAsset",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2446429 - Disclosure - Leases - Narrative (Details)",
     "role": "http://www.f5.com/role/LeasesNarrativeDetails",
     "shortName": "Leases - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-5",
      "lang": "en-US",
      "name": "us-gaap:SubleaseIncome",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R71": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:LeaseCostTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OperatingLeaseCost",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2447430 - Disclosure - Leases - Operating Lease Expense (Details)",
     "role": "http://www.f5.com/role/LeasesOperatingLeaseExpenseDetails",
     "shortName": "Leases - Operating Lease Expense (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:LeaseCostTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OperatingLeaseCost",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R72": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ffiv:AssetsAndLiabilitiesLesseeTableTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OperatingLeaseRightOfUseAsset",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2448431 - Disclosure - Leases - Supplemental Balance Sheet (Details)",
     "role": "http://www.f5.com/role/LeasesSupplementalBalanceSheetDetails",
     "shortName": "Leases - Supplemental Balance Sheet (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ffiv:AssetsAndLiabilitiesLesseeTableTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": null,
      "lang": "en-US",
      "name": "us-gaap:OperatingLeaseWeightedAverageRemainingLeaseTerm1",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R73": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:LesseeOperatingLeaseLiabilityMaturityTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2449432 - Disclosure - Leases - Maturities of Lease Liabilities (Details)",
     "role": "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails",
     "shortName": "Leases - Maturities of Lease Liabilities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:LesseeOperatingLeaseLiabilityMaturityTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R74": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic500f4566a87409ab441e8ac4201f434_I20190930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OperatingLeasesFutureMinimumPaymentsDueCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2450433 - Disclosure - Leases - Operating Lease Future Minimum ASC 840 (Details)",
     "role": "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details",
     "shortName": "Leases - Operating Lease Future Minimum ASC 840 (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic500f4566a87409ab441e8ac4201f434_I20190930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OperatingLeasesFutureMinimumPaymentsDueCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R75": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2453434 - Disclosure - Income Taxes - Narrative (Details)",
     "role": "http://www.f5.com/role/IncomeTaxesNarrativeDetails",
     "shortName": "Income Taxes - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R76": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2454435 - Disclosure - Income Taxes - Components Of Income Before Income Taxes (Details)",
     "role": "http://www.f5.com/role/IncomeTaxesComponentsOfIncomeBeforeIncomeTaxesDetails",
     "shortName": "Income Taxes - Components Of Income Before Income Taxes (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R77": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CurrentFederalTaxExpenseBenefit",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2455436 - Disclosure - Income Taxes - Schedule Of Provision For Income Taxes (Benefit) (Details)",
     "role": "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails",
     "shortName": "Income Taxes - Schedule Of Provision For Income Taxes (Benefit) (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CurrentFederalTaxExpenseBenefit",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R78": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2456437 - Disclosure - Income Taxes - Schedule Of Effective Tax Rate Differs From The U.S. Federal Statutory Rate (Details)",
     "role": "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails",
     "shortName": "Income Taxes - Schedule Of Effective Tax Rate Differs From The U.S. Federal Statutory Rate (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R79": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DeferredTaxAssetsOperatingLossCarryforwards",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2457438 - Disclosure - Income Taxes - Schedule Of Tax Effects To Deferred Tax Assets And Liabilities (Details)",
     "role": "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails",
     "shortName": "Income Taxes - Schedule Of Tax Effects To Deferred Tax Assets And Liabilities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R8": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "1007008 - Statement - Consolidated Statements Of Cash Flows",
     "role": "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows",
     "shortName": "Consolidated Statements Of Cash Flows",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:ShareBasedCompensation",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R80": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ffiv:ScheduleOfReconciliationOfBeginningAndEndingAmountOfUnrecognizedTaxBenefitsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic500f4566a87409ab441e8ac4201f434_I20190930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:UnrecognizedTaxBenefits",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2458439 - Disclosure - Income Taxes - Schedule Of Reconciliation Of Beginning And Ending Amount Of Unrecognized Tax Benefits (Details)",
     "role": "http://www.f5.com/role/IncomeTaxesScheduleOfReconciliationOfBeginningAndEndingAmountOfUnrecognizedTaxBenefitsDetails",
     "shortName": "Income Taxes - Schedule Of Reconciliation Of Beginning And Ending Amount Of Unrecognized Tax Benefits (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ffiv:ScheduleOfReconciliationOfBeginningAndEndingAmountOfUnrecognizedTaxBenefitsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R81": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfTreasuryStockByClassTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ife3aeafb7c6e443dbe4dede6e8a0f3cc_D20200901-20200930",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:StockRepurchasedAndRetiredDuringPeriodShares",
      "reportCount": 1,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2461440 - Disclosure - Shareholders' Equity - Narrative (Details)",
     "role": "http://www.f5.com/role/ShareholdersEquityNarrativeDetails",
     "shortName": "Shareholders' Equity - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ie3090b0e6d0d4d91ab0a26f39e09fab8_I20181031",
      "decimals": "-8",
      "lang": "en-US",
      "name": "us-gaap:StockRepurchaseProgramAuthorizedAmount1",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R82": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfTreasuryStockByClassTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ife3aeafb7c6e443dbe4dede6e8a0f3cc_D20200901-20200930",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:StockRepurchasedAndRetiredDuringPeriodShares",
      "reportCount": 1,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2462441 - Disclosure - Shareholders' Equity - Common Stock Repurchased and Retired Table (Details)",
     "role": "http://www.f5.com/role/ShareholdersEquityCommonStockRepurchasedandRetiredTableDetails",
     "shortName": "Shareholders' Equity - Common Stock Repurchased and Retired Table (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "us-gaap:ScheduleOfTreasuryStockByClassTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ibb4a1d6b0d2b49fd9fa3e2b3da6a867e_D20200701-20200930",
      "decimals": "INF",
      "lang": "en-US",
      "name": "ffiv:CostOfIssuanceOfTreasuryStockShares",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R83": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfShareBasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "2",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate",
      "reportCount": 1,
      "unitRef": "number",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2465442 - Disclosure - Stock-Based Compensation - Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions (Details)",
     "role": "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsDetails",
     "shortName": "Stock-Based Compensation - Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfShareBasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i7b81cc3e11664ca9ae245c64730bd7be_D20191001-20200930",
      "decimals": "INF",
      "lang": "en-US",
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate",
      "reportCount": 1,
      "unique": true,
      "unitRef": "number",
      "xsiNil": "false"
     }
    },
    "R84": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AllocatedShareBasedCompensationExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2466443 - Disclosure - Stock-Based Compensation - Narrative (Details)",
     "role": "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
     "shortName": "Stock-Based Compensation - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AllocatedShareBasedCompensationExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R85": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic500f4566a87409ab441e8ac4201f434_I20190930",
      "decimals": "2",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue",
      "reportCount": 1,
      "unitRef": "usdPerShare",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2467444 - Disclosure - Stock-Based Compensation - Schedule Of Summary Of Restricted Stock Unit Activity (Details)",
     "role": "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails",
     "shortName": "Stock-Based Compensation - Schedule Of Summary Of Restricted Stock Unit Activity (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ibc12707c926140f3b95db9eb5dde1f80_D20191001-20200930",
      "decimals": "INF",
      "lang": "en-US",
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R86": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfShareBasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1",
      "reportCount": 1,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2468445 - Disclosure - Stock-Based Compensation - Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions (Details)",
     "role": "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails",
     "shortName": "Stock-Based Compensation - Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ica5c3f56076645f4a0fd386a4e175940_D20191001-20200930",
      "decimals": "2",
      "lang": "en-US",
      "name": "ffiv:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsPerShare",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usdPerShare",
      "xsiNil": "false"
     }
    },
    "R87": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i32537cdebaba47bf9dd93e232854390b_D20191001-20200930",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2469446 - Disclosure - Stock-Based Compensation - Schedule of Nonvested Restricted Stock Units Activity (Details)",
     "role": "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails",
     "shortName": "Stock-Based Compensation - Schedule of Nonvested Restricted Stock Units Activity (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i32537cdebaba47bf9dd93e232854390b_D20191001-20200930",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R88": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic500f4566a87409ab441e8ac4201f434_I20190930",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber",
      "reportCount": 1,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2470447 - Disclosure - Stock-Based Compensation - Schedule Of Stock Option Activity (Details)",
     "role": "http://www.f5.com/role/StockBasedCompensationScheduleOfStockOptionActivityDetails",
     "shortName": "Stock-Based Compensation - Schedule Of Stock Option Activity (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "INF",
      "lang": "en-US",
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R89": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic3e25c26042447fb8c49846c0f3bfd34_I20200930",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber",
      "reportCount": 1,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2471448 - Disclosure - Stock-Based Compensation - Schedule Of Outstanding Stock Options Currently Exercisable, Vested And Expected To Vest (Details)",
     "role": "http://www.f5.com/role/StockBasedCompensationScheduleOfOutstandingStockOptionsCurrentlyExercisableVestedAndExpectedToVestDetails",
     "shortName": "Stock-Based Compensation - Schedule Of Outstanding Stock Options Currently Exercisable, Vested And Expected To Vest (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "lang": "en-US",
      "name": "us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R9": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SignificantAccountingPoliciesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2101101 - Disclosure - Summary Of Significant Accounting Policies",
     "role": "http://www.f5.com/role/SummaryOfSignificantAccountingPolicies",
     "shortName": "Summary Of Significant Accounting Policies",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SignificantAccountingPoliciesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R90": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ffiv:ScheduleOfEquityBasedAwardIncludingStockOptionsAndRestrictedStockUnitsTableTextBlockTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic1e96c03bc5e416fa97562c763620399_I20190930",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2472449 - Disclosure - Stock-Based Compensation - Schedule Of Equity Based Awards (Including Stock Options And Restricted Stock Units (Details)",
     "role": "http://www.f5.com/role/StockBasedCompensationScheduleOfEquityBasedAwardsIncludingStockOptionsAndRestrictedStockUnitsDetails",
     "shortName": "Stock-Based Compensation - Schedule Of Equity Based Awards (Including Stock Options And Restricted Stock Units (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "ffiv:ScheduleOfEquityBasedAwardIncludingStockOptionsAndRestrictedStockUnitsTableTextBlockTableTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic1e96c03bc5e416fa97562c763620399_I20190930",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant",
      "reportCount": 1,
      "unique": true,
      "unitRef": "shares",
      "xsiNil": "false"
     }
    },
    "R91": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfQuarterlyFinancialInformationTableTextBlock",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ibb4a1d6b0d2b49fd9fa3e2b3da6a867e_D20200701-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2475450 - Disclosure - Net Income Per Share (Details)",
     "role": "http://www.f5.com/role/NetIncomePerShareDetails",
     "shortName": "Net Income Per Share (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R92": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i6aea63d90eb7412693f356b346f0e713_I20200930",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PurchaseCommitmentRemainingMinimumAmountCommitted",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2477451 - Disclosure - Commitments And Contingencies - Narrative (Details)",
     "role": "http://www.f5.com/role/CommitmentsAndContingenciesNarrativeDetails",
     "shortName": "Commitments And Contingencies - Narrative (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i6aea63d90eb7412693f356b346f0e713_I20200930",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PurchaseCommitmentRemainingMinimumAmountCommitted",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R93": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i7d1599afda114d3488c7df093a4cd5f3_D20191001-20191231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "ffiv:NumberofEmployeesinReductionofForceProgram",
      "reportCount": 1,
      "unique": true,
      "unitRef": "employee",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2480452 - Disclosure - Restructuring Charges (Details)",
     "role": "http://www.f5.com/role/RestructuringChargesDetails",
     "shortName": "Restructuring Charges (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i7d1599afda114d3488c7df093a4cd5f3_D20191001-20191231",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "ffiv:NumberofEmployeesinReductionofForceProgram",
      "reportCount": 1,
      "unique": true,
      "unitRef": "employee",
      "xsiNil": "false"
     }
    },
    "R94": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfRestructuringAndRelatedCostsTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ic500f4566a87409ab441e8ac4201f434_I20190930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RestructuringReserve",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2481453 - Disclosure - Restructuring Charges - Restructuring Activity (Details)",
     "role": "http://www.f5.com/role/RestructuringChargesRestructuringActivityDetails",
     "shortName": "Restructuring Charges - Restructuring Activity (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "us-gaap:ScheduleOfRestructuringAndRelatedCostsTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-3",
      "lang": "en-US",
      "name": "us-gaap:PaymentsForRestructuring",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R95": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedContributionPlanEmployerDiscretionaryContributionAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2483454 - Disclosure - Employee Benefit Plans (Details)",
     "role": "http://www.f5.com/role/EmployeeBenefitPlansDetails",
     "shortName": "Employee Benefit Plans (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "span",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "-5",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DefinedContributionPlanEmployerDiscretionaryContributionAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "usd",
      "xsiNil": "false"
     }
    },
    "R96": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "div",
       "us-gaap:SegmentReportingPolicyPolicyTextBlock",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "INF",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NumberOfReportableSegments",
      "reportCount": 1,
      "unitRef": "segment",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2486455 - Disclosure - Segment Information (Details)",
     "role": "http://www.f5.com/role/SegmentInformationDetails",
     "shortName": "Segment Information (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i82e476fafec240e89bb498216b175cd2_D20191001-20200930",
      "decimals": "INF",
      "lang": "en-US",
      "name": "ffiv:NumberofGeographicRegions",
      "reportCount": 1,
      "unique": true,
      "unitRef": "geographic_region",
      "xsiNil": "false"
     }
    },
    "R97": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfQuarterlyFinancialInformationTableTextBlock",
       "div",
       "ix:continuation",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "ibb4a1d6b0d2b49fd9fa3e2b3da6a867e_D20200701-20200930",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "2489456 - Disclosure - Quarterly Results Of Operations (Unaudited) - Schedule Of Quarterly Results Of Operations (Details)",
     "role": "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails",
     "shortName": "Quarterly Results Of Operations (Unaudited) - Schedule Of Quarterly Results Of Operations (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R9999": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "td",
       "tr",
       "table",
       "div",
       "body",
       "html"
      ],
      "baseRef": "ffiv-20200930.htm",
      "contextRef": "i149b799abc0d4dc085855c180a5e2380_I20181001",
      "decimals": "-3",
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption",
      "reportCount": 1,
      "unitRef": "usd",
      "xsiNil": "false"
     },
     "groupType": "",
     "isDefault": "false",
     "longName": "Uncategorized Items - ffiv-20200930.htm",
     "role": "http://xbrl.sec.gov/role/uncategorizedFacts",
     "shortName": "Uncategorized Items - ffiv-20200930.htm",
     "subGroupType": "",
     "uniqueAnchor": null
    }
   },
   "segmentCount": 89,
   "tag": {
    "country_US": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "UNITED STATES",
        "terseLabel": "United States [Member]"
       }
      }
     },
     "localname": "US",
     "nsuri": "http://xbrl.sec.gov/country/2017-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_CityAreaCode": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Area code of city",
        "label": "City Area Code",
        "terseLabel": "City Area Code"
       }
      }
     },
     "localname": "CityAreaCode",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_CoverAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Cover page.",
        "label": "Cover [Abstract]",
        "terseLabel": "Cover [Abstract]"
       }
      }
     },
     "localname": "CoverAbstract",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "gMonthDayItemType"
    },
    "dei_DocumentAnnualReport": {
     "auth_ref": [
      "r482"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Boolean flag that is true only for a form used as an annual report.",
        "label": "Document Annual Report",
        "terseLabel": "Document Annual Report"
       }
      }
     },
     "localname": "DocumentAnnualReport",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "booleanItemType"
    },
    "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "fiscalPeriodItemType"
    },
    "dei_DocumentFiscalYearFocus": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This is focus fiscal year of the document report in CCYY 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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "gYearItemType"
    },
    "dei_DocumentPeriodEndDate": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented.  If there is no historical data in the report, use the filing date. The format of the date is CCYY-MM-DD.",
        "label": "Document Period End Date",
        "terseLabel": "Document Period End Date"
       }
      }
     },
     "localname": "DocumentPeriodEndDate",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "dateItemType"
    },
    "dei_DocumentTransitionReport": {
     "auth_ref": [
      "r481"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Boolean flag that is true only for a form used as a transition report.",
        "label": "Document Transition Report",
        "terseLabel": "Document Transition Report"
       }
      }
     },
     "localname": "DocumentTransitionReport",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "submissionTypeItemType"
    },
    "dei_DocumentsIncorporatedByReferenceTextBlock": {
     "auth_ref": [
      "r479"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Documents incorporated by reference.",
        "label": "Documents Incorporated by Reference [Text Block]",
        "terseLabel": "Documents Incorporated by Reference [Text Block]"
       }
      }
     },
     "localname": "DocumentsIncorporatedByReferenceTextBlock",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "textBlockItemType"
    },
    "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",
        "terseLabel": "Entity Address, Address Line One"
       }
      }
     },
     "localname": "EntityAddressAddressLine1",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressCityOrTown": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Name of the City or Town",
        "label": "Entity Address, City or Town",
        "terseLabel": "Entity Address, City or Town"
       }
      }
     },
     "localname": "EntityAddressCityOrTown",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressPostalZipCode": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Code for the postal or zip code",
        "label": "Entity Address, Postal Zip Code",
        "terseLabel": "Entity Address, Postal Zip Code"
       }
      }
     },
     "localname": "EntityAddressPostalZipCode",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressStateOrProvince": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Name of the state or province.",
        "label": "Entity Address, State or Province",
        "terseLabel": "Entity Address, State or Province"
       }
      }
     },
     "localname": "EntityAddressStateOrProvince",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "stateOrProvinceItemType"
    },
    "dei_EntityCentralIndexKey": {
     "auth_ref": [
      "r483"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "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",
        "terseLabel": "Entity Current Reporting Status"
       }
      }
     },
     "localname": "EntityCurrentReportingStatus",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityEmergingGrowthCompany": {
     "auth_ref": [
      "r483"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Indicate if registrant meets the emerging growth company criteria.",
        "label": "Entity Emerging Growth Company",
        "terseLabel": "Entity Emerging Growth Company"
       }
      }
     },
     "localname": "EntityEmergingGrowthCompany",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "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",
        "terseLabel": "Entity File Number"
       }
      }
     },
     "localname": "EntityFileNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "fileNumberItemType"
    },
    "dei_EntityFilerCategory": {
     "auth_ref": [
      "r483"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "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",
        "terseLabel": "Entity Incorporation, State or Country Code"
       }
      }
     },
     "localname": "EntityIncorporationStateCountryCode",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "edgarStateCountryItemType"
    },
    "dei_EntityInteractiveDataCurrent": {
     "auth_ref": [
      "r484"
     ],
     "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",
        "terseLabel": "Entity Interactive Data Current"
       }
      }
     },
     "localname": "EntityInteractiveDataCurrent",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityPublicFloat": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The aggregate market value of the voting and non-voting common equity held by non-affiliates computed by reference to the price at which the common equity was last sold, or the average bid and asked price of such common equity, as of the last business day of the registrant's most recently completed second fiscal quarter.",
        "label": "Entity Public Float",
        "terseLabel": "Entity Public Float"
       }
      }
     },
     "localname": "EntityPublicFloat",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "monetaryItemType"
    },
    "dei_EntityRegistrantName": {
     "auth_ref": [
      "r483"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityShellCompany": {
     "auth_ref": [
      "r483"
     ],
     "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",
        "terseLabel": "Entity Shell Company"
       }
      }
     },
     "localname": "EntityShellCompany",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntitySmallBusiness": {
     "auth_ref": [
      "r483"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Indicates that the company is a Smaller Reporting Company (SRC).",
        "label": "Entity Small Business",
        "terseLabel": "Entity Small Business"
       }
      }
     },
     "localname": "EntitySmallBusiness",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntityTaxIdentificationNumber": {
     "auth_ref": [
      "r483"
     ],
     "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",
        "terseLabel": "Entity Tax Identification Number"
       }
      }
     },
     "localname": "EntityTaxIdentificationNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "employerIdItemType"
    },
    "dei_EntityVoluntaryFilers": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Indicate 'Yes' or 'No' if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.",
        "label": "Entity Voluntary Filers",
        "terseLabel": "Entity Voluntary Filers"
       }
      }
     },
     "localname": "EntityVoluntaryFilers",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityWellKnownSeasonedIssuer": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Indicate 'Yes' or 'No' if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Is used on Form Type: 10-K, 10-Q, 8-K, 20-F, 6-K, 10-K/A, 10-Q/A, 20-F/A, 6-K/A, N-CSR, N-Q, N-1A.",
        "label": "Entity Well-known Seasoned Issuer",
        "terseLabel": "Entity Well-known Seasoned Issuer"
       }
      }
     },
     "localname": "EntityWellKnownSeasonedIssuer",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_LocalPhoneNumber": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Local phone number for entity.",
        "label": "Local Phone Number",
        "terseLabel": "Local Phone Number"
       }
      }
     },
     "localname": "LocalPhoneNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_Security12bTitle": {
     "auth_ref": [
      "r478"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Title of a 12(b) registered security.",
        "label": "Title of 12(b) Security",
        "terseLabel": "Title of 12(b) Security"
       }
      }
     },
     "localname": "Security12bTitle",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "securityTitleItemType"
    },
    "dei_SecurityExchangeName": {
     "auth_ref": [
      "r480"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Name of the Exchange on which a security is registered.",
        "label": "Security Exchange Name",
        "terseLabel": "Security Exchange Name"
       }
      }
     },
     "localname": "SecurityExchangeName",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "edgarExchangeCodeItemType"
    },
    "dei_TradingSymbol": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Trading symbol of an instrument as listed on an exchange.",
        "label": "Trading Symbol",
        "terseLabel": "Trading Symbol"
       }
      }
     },
     "localname": "TradingSymbol",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CoverPage"
     ],
     "xbrltype": "tradingSymbolItemType"
    },
    "ffiv_AccountsReceivablePaymentTermPeriodInDays": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Accounts Receivable Payment Term Period In Days",
        "label": "Accounts Receivable Payment Term Period In Days",
        "terseLabel": "Accounts Receivable Payment Term Period In Days"
       }
      }
     },
     "localname": "AccountsReceivablePaymentTermPeriodInDays",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "ffiv_AlternateBaseRateMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Alternate Base Rate [Member]",
        "label": "Alternate Base Rate [Member]",
        "terseLabel": "Alternate Base Rate [Member]"
       }
      }
     },
     "localname": "AlternateBaseRateMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_AnnualEquityProgramMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Annual Equity Program [Member]",
        "label": "Annual Equity Program [Member]",
        "terseLabel": "Annual Equity Program [Member]"
       }
      }
     },
     "localname": "AnnualEquityProgramMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_AssetsAcquiredAbstractAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Assets Acquired [Abstract]",
        "label": "AssetsAcquiredAbstract [Abstract]",
        "terseLabel": "Assets acquired"
       }
      }
     },
     "localname": "AssetsAcquiredAbstractAbstract",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_AssetsAndLiabilitiesLesseeTableTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Assets And Liabilities Lessee Table [Table Text Block]",
        "label": "Assets And Liabilities Lessee Table [Table Text Block]",
        "terseLabel": "Assets And Liabilities Lessee"
       }
      }
     },
     "localname": "AssetsAndLiabilitiesLesseeTableTableTextBlock",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/LeasesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ffiv_AssetsMeasuredatFairValueonaNonrecurringBasisAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Assets Measured at Fair Value on a Nonrecurring Basis [Abstract]",
        "label": "Assets Measured at Fair Value on a Nonrecurring Basis [Abstract]",
        "terseLabel": "Assets Measured at Fair Value on a Nonrecurring Basis [Abstract]"
       }
      }
     },
     "localname": "AssetsMeasuredatFairValueonaNonrecurringBasisAbstract",
     "nsuri": "http://www.f5.com/20200930",
     "xbrltype": "stringItemType"
    },
    "ffiv_BalanceSheetDetailsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Balance Sheet Details [Abstract]",
        "label": "Balance Sheet Details [Abstract]",
        "terseLabel": "Balance Sheet Details [Abstract]"
       }
      }
     },
     "localname": "BalanceSheetDetailsAbstract",
     "nsuri": "http://www.f5.com/20200930",
     "xbrltype": "stringItemType"
    },
    "ffiv_BusinessCombinationRecognizedIdentifiableAssetAcquiredandLiabilityAssumedOperatingLeaseLeaseLiabilities": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Business Combination, Recognized Identifiable Asset Acquired and Liability Assumed, Operating Lease, Lease Liabilities",
        "label": "Business Combination, Recognized Identifiable Asset Acquired and Liability Assumed, Operating Lease, Lease Liabilities",
        "negatedTerseLabel": "Operating lease liabilities"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetAcquiredandLiabilityAssumedOperatingLeaseLeaseLiabilities",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_BusinessCombinationRecognizedIdentifiableAssetAcquiredandLiabilityAssumedOperatingLeaseRightOfUseAssets": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Business Combination, Recognized Identifiable Asset Acquired and Liability Assumed, Operating Lease, Right-Of-Use Assets",
        "label": "Business Combination, Recognized Identifiable Asset Acquired and Liability Assumed, Operating Lease, Right-Of-Use Assets",
        "terseLabel": "Operating lease right-of-use assets"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetAcquiredandLiabilityAssumedOperatingLeaseRightOfUseAssets",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_CapitalizedContractAcquisitionCostsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Capitalized Contract Acquisition Costs [Abstract]",
        "label": "Capitalized Contract Acquisition Costs [Abstract]",
        "terseLabel": "Capitalized Contract Acquisition Costs [Abstract]"
       }
      }
     },
     "localname": "CapitalizedContractAcquisitionCostsAbstract",
     "nsuri": "http://www.f5.com/20200930",
     "xbrltype": "stringItemType"
    },
    "ffiv_CapitalizedContractCostCumulativeCatchupAdjustmenttoRevenueChangeinEstimateofTransactionPrice": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Capitalized Contract Cost, Cumulative Catch-up Adjustment to Revenue, Change in Estimate of Transaction Price",
        "label": "Capitalized Contract Cost, Cumulative Catch-up Adjustment to Revenue, Change in Estimate of Transaction Price",
        "terseLabel": "Capitalized Contract Cost, Cumulative Catch-up Adjustment to Revenue, Change in Estimate of Transaction Price"
       }
      }
     },
     "localname": "CapitalizedContractCostCumulativeCatchupAdjustmenttoRevenueChangeinEstimateofTransactionPrice",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersCapitalizedContractAcquisitionCostsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_CapitalizedContractCostDeferredAcquisitionCosts": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Capitalized Contract Cost, Deferred Acquisition Costs",
        "label": "Capitalized Contract Cost, Deferred Acquisition Costs",
        "terseLabel": "Capitalized Contract Cost, Deferred Acquisition Costs"
       }
      }
     },
     "localname": "CapitalizedContractCostDeferredAcquisitionCosts",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersCapitalizedContractAcquisitionCostsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_ChangeInContractWithCustomerAssetRollForward": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Change in Contract with Customer, Asset [Roll Forward]",
        "label": "Change in Contract with Customer, Asset [Roll Forward]",
        "terseLabel": "Change in Contract with Customer, Asset [Roll Forward]"
       }
      }
     },
     "localname": "ChangeInContractWithCustomerAssetRollForward",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersContractAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_ChangeInContractWithCustomerLiabilityRollForward": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Change in Contract with Customer, Liability [Roll Forward]",
        "label": "Change in Contract with Customer, Liability [Roll Forward]",
        "terseLabel": "Change in Contract with Customer, Liability [Roll Forward]"
       }
      }
     },
     "localname": "ChangeInContractWithCustomerLiabilityRollForward",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersContractAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_CommitmentsAndContingenciesLineItems": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Commitments And Contingencies [Line Items]",
        "label": "Commitments And Contingencies [Line Items]",
        "terseLabel": "Commitments And Contingencies [Line Items]"
       }
      }
     },
     "localname": "CommitmentsAndContingenciesLineItems",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/CommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_CommitmentsAndContingenciesTable": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Commitments And Contingencies [Table]",
        "label": "Commitments And Contingencies [Table]",
        "terseLabel": "Commitments And Contingencies [Table]"
       }
      }
     },
     "localname": "CommitmentsAndContingenciesTable",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/CommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_CommonStockRepurchaseLineItems": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "[Line Items] for Common Stock Repurchase [Table]",
        "label": "Common Stock Repurchase [Line Items]",
        "terseLabel": "Common Stock Repurchase [Line Items]"
       }
      }
     },
     "localname": "CommonStockRepurchaseLineItems",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/ShareholdersEquityNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_CommonStockRepurchaseTable": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Common Stock Repurchase [Table]",
        "label": "Common Stock Repurchase [Table]",
        "terseLabel": "Common Stock Repurchase [Table]"
       }
      }
     },
     "localname": "CommonStockRepurchaseTable",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/ShareholdersEquityNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_ContractwithCustomerAssetNewContractAdditions": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Contract with Customer, Asset, New Contract Additions",
        "label": "Contract with Customer, Asset, New Contract Additions",
        "terseLabel": "Contract asset net additions"
       }
      }
     },
     "localname": "ContractwithCustomerAssetNewContractAdditions",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersContractAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_ContractwithCustomerAssetRevenueRecognizedButNotYetBilled": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Contract with Customer, Asset, Revenue Recognized But Not Yet Billed",
        "label": "Contract with Customer, Asset, Revenue Recognized But Not Yet Billed",
        "terseLabel": "Revenue recognized during period but not yet billed"
       }
      }
     },
     "localname": "ContractwithCustomerAssetRevenueRecognizedButNotYetBilled",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersContractAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_ContractwithCustomerLiabilityRevenueRecognizedButNotYetBilled": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Contract with Customer, Liability, Revenue Recognized But Not Yet Billed",
        "label": "Contract with Customer, Liability, Revenue Recognized But Not Yet Billed",
        "terseLabel": "Amounts billed but not recognized as revenues"
       }
      }
     },
     "localname": "ContractwithCustomerLiabilityRevenueRecognizedButNotYetBilled",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersContractAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_CostOfIssuanceOfTreasuryStock": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 6.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Cost of Issuance of Treasury Stock",
        "label": "Cost of Issuance of Treasury Stock",
        "negatedTerseLabel": "Taxes paid related to net share settlement of equity awards"
       }
      }
     },
     "localname": "CostOfIssuanceOfTreasuryStock",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity",
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_CostOfIssuanceOfTreasuryStockShares": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Cost of Issuance of Treasury Stock, Shares",
        "label": "Cost of Issuance of Treasury Stock, Shares",
        "negatedTerseLabel": "Taxes paid related to net share settlement of equity awards, shares",
        "terseLabel": "Cost of Issuance of Treasury Stock, Shares"
       }
      }
     },
     "localname": "CostOfIssuanceOfTreasuryStockShares",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity",
      "http://www.f5.com/role/ShareholdersEquityCommonStockRepurchasedandRetiredTableDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "ffiv_CustomerOneMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Customer One [Member]",
        "label": "Customer One [Member]",
        "terseLabel": "Customer One [Member]"
       }
      }
     },
     "localname": "CustomerOneMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_CustomerThreeMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Customer Three",
        "label": "Customer Three [Member]",
        "terseLabel": "Customer Three [Member]"
       }
      }
     },
     "localname": "CustomerThreeMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_CustomerTwoMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Customer Two [Member]",
        "label": "Customer Two [Member]",
        "terseLabel": "Customer Two [Member]"
       }
      }
     },
     "localname": "CustomerTwoMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_DeferredTaxAssetsTaxCreditCarryforwardsSubjecttoExpiration": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Deferred Tax Assets, Tax Credit Carryforwards, Subject to Expiration",
        "label": "Deferred Tax Assets, Tax Credit Carryforwards, Subject to Expiration",
        "terseLabel": "Deferred Tax Assets, Tax Credit Carryforwards, Subject to Expiration"
       }
      }
     },
     "localname": "DeferredTaxAssetsTaxCreditCarryforwardsSubjecttoExpiration",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_DefinedContributionPlanEmployerContributionVestingPeriod": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Defined Contribution Plan, Employer Contribution, Vesting Period",
        "label": "Defined Contribution Plan, Employer Contribution, Vesting Period",
        "terseLabel": "Employer contribution, vesting period"
       }
      }
     },
     "localname": "DefinedContributionPlanEmployerContributionVestingPeriod",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/EmployeeBenefitPlansDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "ffiv_EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActAmount": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails": {
       "order": 7.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Effective Income Tax Rate Reconciliation, Tax Cuts And Jobs Act, Amount",
        "label": "EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActAmount",
        "terseLabel": "EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActAmount"
       }
      }
     },
     "localname": "EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActAmount",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_EquityBasedAwardsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Equity Based Awards [Member]",
        "label": "Equity Based Awards [Member]",
        "terseLabel": "Equity Based Awards [Member]"
       }
      }
     },
     "localname": "EquityBasedAwardsMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfEquityBasedAwardsIncludingStockOptionsAndRestrictedStockUnitsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_F5NetworksAcquisitionofNginxMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "F5 Networks Acquisition of Nginx [Member]",
        "label": "F5 Networks Acquisition of Nginx [Member]",
        "terseLabel": "F5 Networks Acquisition of Nginx"
       }
      }
     },
     "localname": "F5NetworksAcquisitionofNginxMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails",
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_F5NetworksMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "F5 Networks",
        "label": "F5 Networks [Member]",
        "terseLabel": "F5 Networks [Member]"
       }
      }
     },
     "localname": "F5NetworksMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_FairValueOfIntangibleAssetsAbstractAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Fair Value of intangible Assets [Abstract]",
        "label": "Fair Value of intangible Assets Abstract [Abstract]",
        "terseLabel": "Fair value of tangible assets:"
       }
      }
     },
     "localname": "FairValueOfIntangibleAssetsAbstractAbstract",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_FiniteLivedIntangibleAssetsTotalAmortizationExpenseForNextFiveYears": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsEstimatedAmortizationExpenseForIntangibleAssetsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Finite Lived Intangible Assets Total Amortization Expense For Next Five Years",
        "label": "Finite Lived Intangible Assets Total Amortization Expense For Next Five Years",
        "totalLabel": "Total estimated amortization expense"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsTotalAmortizationExpenseForNextFiveYears",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsEstimatedAmortizationExpenseForIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_FutureMinimumOperatingNetLeasePayments": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Future minimum operating net lease payments",
        "label": "Future Minimum Operating Net Lease Payments",
        "totalLabel": "Net Lease Payments, Total"
       }
      }
     },
     "localname": "FutureMinimumOperatingNetLeasePayments",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_FutureMinimumOperatingNetLeasePaymentsFiscalYearMaturityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Future Minimum Operating Net Lease Payments Fiscal Year Maturity [Abstract]",
        "label": "Future Minimum Operating Net Lease Payments Fiscal Year Maturity [Abstract]",
        "terseLabel": "Future Minimum Operating Net Lease Payments Fiscal Year Maturity [Abstract]"
       }
      }
     },
     "localname": "FutureMinimumOperatingNetLeasePaymentsFiscalYearMaturityAbstract",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_FutureMinimumOperatingNetLeasePaymentsWithinFiveYear": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Future minimum operating net lease payments within five year",
        "label": "Future Minimum Operating Net Lease Payments Within Five Year",
        "totalLabel": "2024"
       }
      }
     },
     "localname": "FutureMinimumOperatingNetLeasePaymentsWithinFiveYear",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_FutureMinimumOperatingNetLeasePaymentsWithinFourYear": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Future minimum operating net lease payments within four year",
        "label": "Future Minimum Operating Net Lease Payments Within Four Year",
        "totalLabel": "2023"
       }
      }
     },
     "localname": "FutureMinimumOperatingNetLeasePaymentsWithinFourYear",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_FutureMinimumOperatingNetLeasePaymentsWithinOneYear": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Future minimum operating net lease payments within one year",
        "label": "Future Minimum Operating Net Lease Payments Within One Year",
        "totalLabel": "2020"
       }
      }
     },
     "localname": "FutureMinimumOperatingNetLeasePaymentsWithinOneYear",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_FutureMinimumOperatingNetLeasePaymentsWithinThereafter": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Future minimum operating, net lease payments, within thereafter",
        "label": "Future Minimum Operating Net Lease Payments Within Thereafter",
        "totalLabel": "Thereafter"
       }
      }
     },
     "localname": "FutureMinimumOperatingNetLeasePaymentsWithinThereafter",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_FutureMinimumOperatingNetLeasePaymentsWithinThreeYear": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Future minimum operating, net lease payments, within three year",
        "label": "Future Minimum Operating Net Lease Payments Within Three Year",
        "totalLabel": "2022"
       }
      }
     },
     "localname": "FutureMinimumOperatingNetLeasePaymentsWithinThreeYear",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_FutureMinimumOperatingNetLeasePaymentsWithinTwoYear": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Future minimum operating net lease payments within two year",
        "label": "Future Minimum Operating Net Lease Payments Within Two Year",
        "totalLabel": "2021"
       }
      }
     },
     "localname": "FutureMinimumOperatingNetLeasePaymentsWithinTwoYear",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_HardwareMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Hardware [Member]",
        "label": "Hardware [Member]",
        "terseLabel": "Hardware [Member]"
       }
      }
     },
     "localname": "HardwareMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_IncreaseDecreaseinLeaseLiabilities": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 15.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Increase (Decrease) in Lease Liabilities",
        "label": "Increase (Decrease) in Lease Liabilities",
        "terseLabel": "Lease liabilities"
       }
      }
     },
     "localname": "IncreaseDecreaseinLeaseLiabilities",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_IndexMembersMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Index Members",
        "label": "Index Members [Member]",
        "terseLabel": "Index Members [Member]"
       }
      }
     },
     "localname": "IndexMembersMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_LeaseLiabilities": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Lease Liabilities",
        "label": "Lease Liabilities",
        "terseLabel": "Lease Liabilities"
       }
      }
     },
     "localname": "LeaseLiabilities",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/LeasesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_LessorOperatingLeasePaymentsToBeReceivedTwoToThreeYears": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Lessor, Operating Lease, Payments to be Received, Two To Three Years",
        "label": "Lessor, Operating Lease, Payments to be Received, Two To Three Years",
        "terseLabel": "Lessor, Operating Lease, Payments to be Received, Two To Three Years"
       }
      }
     },
     "localname": "LessorOperatingLeasePaymentsToBeReceivedTwoToThreeYears",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/LeasesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_LiabilitiesAssumedAbstractAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Liabilities Assumed [Abstract]",
        "label": "Liabilities Assumed Abstract [Abstract]",
        "terseLabel": "Liabilities assumed"
       }
      }
     },
     "localname": "LiabilitiesAssumedAbstractAbstract",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_LineOfCreditFacilityConditionalIncreaseInBorrowingCapacity": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Line Of Credit Facility, Conditional Increase In Borrowing Capacity",
        "label": "Line Of Credit Facility, Conditional Increase In Borrowing Capacity",
        "terseLabel": "Conditional Increase In Borrowing Capacity"
       }
      }
     },
     "localname": "LineOfCreditFacilityConditionalIncreaseInBorrowingCapacity",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_LineOfCreditFacilityLengthOfExtensionPeriod": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Line Of Credit Facility, Length Of Extension Period",
        "label": "Line Of Credit Facility, Length Of Extension Period",
        "terseLabel": "Length Of Extension Period"
       }
      }
     },
     "localname": "LineOfCreditFacilityLengthOfExtensionPeriod",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "ffiv_LineOfCreditFacilityNumberOfExtensions": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Line Of Credit Facility, Number Of Extensions",
        "label": "Line Of Credit Facility, Number Of Extensions",
        "terseLabel": "Number Of Extensions"
       }
      }
     },
     "localname": "LineOfCreditFacilityNumberOfExtensions",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "ffiv_LongTermInvestmentsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Long Term Investments [Member]",
        "label": "Long Term Investments [Member]",
        "terseLabel": "Long-Term Investments [Member]"
       }
      }
     },
     "localname": "LongTermInvestmentsMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsTables"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_MemberAxis": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Member",
        "label": "Member [Axis]",
        "terseLabel": "Member [Axis]"
       }
      }
     },
     "localname": "MemberAxis",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_MemberDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Member",
        "label": "Member [Domain]",
        "terseLabel": "Member [Domain]"
       }
      }
     },
     "localname": "MemberDomain",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_MunicipalBondsAndNotesMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Municipal Bonds and Notes [Member]",
        "label": "Municipal Bonds And Notes [Member]",
        "terseLabel": "Municipal Bonds And Notes [Member]"
       }
      }
     },
     "localname": "MunicipalBondsAndNotesMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_NetIncomePerShareAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Net Income Per Share [Abstract]",
        "label": "Net Income Per Share [Abstract]",
        "terseLabel": "Net Income Per Share [Abstract]"
       }
      }
     },
     "localname": "NetIncomePerShareAbstract",
     "nsuri": "http://www.f5.com/20200930",
     "xbrltype": "stringItemType"
    },
    "ffiv_NginxAcquisitionEquityIncentivePlanMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Nginx Acquisition Equity Incentive Plan [Member]",
        "label": "Nginx Acquisition Equity Incentive Plan [Member]",
        "terseLabel": "Nginx Acquisition Equity Incentive Plan [Member]"
       }
      }
     },
     "localname": "NginxAcquisitionEquityIncentivePlanMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_NginxInc.2011SharePlanMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Nginx, Inc. 2011 Share Plan [Member]",
        "label": "Nginx, Inc. 2011 Share Plan [Member]",
        "terseLabel": "Nginx, Inc. 2011 Share Plan [Member]"
       }
      }
     },
     "localname": "NginxInc.2011SharePlanMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_NonCashOperatingLeaseCosts": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Non-Cash Operating Lease Costs",
        "label": "Non-Cash Operating Lease Costs",
        "terseLabel": "Non-cash operating lease costs"
       }
      }
     },
     "localname": "NonCashOperatingLeaseCosts",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_NoncompetitionAgreementsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Non-competition Agreements [Member]",
        "label": "Non-competition Agreements [Member]",
        "terseLabel": "Non-competition Agreements"
       }
      }
     },
     "localname": "NoncompetitionAgreementsMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_November12016Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "November 1, 2016 [Member]",
        "label": "November 1, 2016 [Member]",
        "terseLabel": "November 1, 2016 [Member]"
       }
      }
     },
     "localname": "November12016Member",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_November12017Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "November 1, 2017 [Member]",
        "label": "November 1, 2017 [Member]",
        "terseLabel": "November 1, 2017 [Member]"
       }
      }
     },
     "localname": "November12017Member",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_November12018Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "November 1, 2018 [Member]",
        "label": "November 1, 2018 [Member]",
        "terseLabel": "November 1, 2018 [Member]"
       }
      }
     },
     "localname": "November12018Member",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_November12019Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "November 1, 2019",
        "label": "November 1, 2019 [Member]",
        "terseLabel": "November 1, 2019 [Member]"
       }
      }
     },
     "localname": "November12019Member",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_NumberofEmployeesinReductionofForceProgram": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of Employees in Reduction of Force Program",
        "label": "Number of Employees in Reduction of Force Program",
        "terseLabel": "Number of Employees in Reduction of Force Program"
       }
      }
     },
     "localname": "NumberofEmployeesinReductionofForceProgram",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/RestructuringChargesDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "ffiv_NumberofGeographicRegions": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of Geographic Regions",
        "label": "Number of Geographic Regions",
        "terseLabel": "Number of Geographic Regions"
       }
      }
     },
     "localname": "NumberofGeographicRegions",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "ffiv_OctoberTwentySixTwoThousandTenProgramAndCostOfIssuanceOfTreasuryStockMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "October Twenty Six Two Thousand Ten Program and Cost of Issuance of Treasury Stock",
        "label": "October Twenty Six Two Thousand Ten Program and Cost of Issuance of Treasury Stock [Member]",
        "terseLabel": "October Twenty Six Two Thousand Ten Program and Cost of Issuance of Treasury Stock [Member]"
       }
      }
     },
     "localname": "OctoberTwentySixTwoThousandTenProgramAndCostOfIssuanceOfTreasuryStockMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/ShareholdersEquityCommonStockRepurchasedandRetiredTableDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_OctoberTwentySixTwoThousandTenProgramMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "October Twenty Six Two Thousand Ten Program [Member]",
        "label": "October Twenty Six Two Thousand Ten Program [Member]",
        "verboseLabel": "October Twenty Six Two Thousand Ten Program [Member]"
       }
      }
     },
     "localname": "OctoberTwentySixTwoThousandTenProgramMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/ShareholdersEquityNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_OperatingLeaseNumberofSquareFeet": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Operating Lease, Number of Square Feet",
        "label": "Operating Lease, Number of Square Feet",
        "terseLabel": "Operating Lease, Number of Square Feet"
       }
      }
     },
     "localname": "OperatingLeaseNumberofSquareFeet",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/LeasesNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "ffiv_OtherAmericasMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Other Americas [Member]",
        "label": "Other Americas [Member]",
        "terseLabel": "Other Americas [Member]"
       }
      }
     },
     "localname": "OtherAmericasMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_OtherInternationalCountriesMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Other International Countries [Member]",
        "label": "Other International Countries [Member]",
        "terseLabel": "Other International Countries [Member]"
       }
      }
     },
     "localname": "OtherInternationalCountriesMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_PercentageOfAnnualIncreaseinStandaloneSoftwareGoalToBeAchievedForPerformanceStockGrant": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage Of Annual Increase in Stand-alone Software Goal To Be Achieved For Performance Stock Grant",
        "label": "Percentage Of Annual Increase in Stand-alone Software Goal To Be Achieved For Performance Stock Grant",
        "terseLabel": "Percentage Of Annual Increase in Stand-alone Software Goal To Be Achieved For Performance Stock Grant"
       }
      }
     },
     "localname": "PercentageOfAnnualIncreaseinStandaloneSoftwareGoalToBeAchievedForPerformanceStockGrant",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ffiv_PercentageOfAnnualPerformanceStockGrantBasedOnAchievingAnnualIncreaseinStandaloneSoftwareGoal": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage Of Annual Performance Stock Grant Based On Achieving Annual Increase in Stand-alone Software Goal",
        "label": "Percentage Of Annual Performance Stock Grant Based On Achieving Annual Increase in Stand-alone Software Goal",
        "terseLabel": "Percentage Of Annual Performance Stock Grant Based On Achieving Annual Increase in Stand-alone Software Goal"
       }
      }
     },
     "localname": "PercentageOfAnnualPerformanceStockGrantBasedOnAchievingAnnualIncreaseinStandaloneSoftwareGoal",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ffiv_PercentageOfAnnualPerformanceStockGrantBasedOnAchievingAnnualRevenueGoal": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage Of Annual Performance Stock Grant Based On Achieving Annual Revenue Goal",
        "label": "Percentage Of Annual Performance Stock Grant Based On Achieving Annual Revenue Goal",
        "terseLabel": "Percentage Of Annual Performance Stock Grant Based On Achieving Annual Revenue Goal"
       }
      }
     },
     "localname": "PercentageOfAnnualPerformanceStockGrantBasedOnAchievingAnnualRevenueGoal",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ffiv_PercentageOfAnnualPerformanceStockGrantBasedOnAchievingRelativeTotalShareholderReturnBenchmarkedtotheSP500IndexGoal": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage Of Annual Performance Stock Grant Based On Achieving Relative Total Shareholder Return Benchmarked to the S&amp;P 500 Index Goal",
        "label": "Percentage Of Annual Performance Stock Grant Based On Achieving Relative Total Shareholder Return Benchmarked to the S&amp;P 500 Index Goal",
        "terseLabel": "Percentage Of Annual Performance Stock Grant Based On Achieving Relative Total Shareholder Return Benchmarked to the S&amp;P 500 Index Goal"
       }
      }
     },
     "localname": "PercentageOfAnnualPerformanceStockGrantBasedOnAchievingRelativeTotalShareholderReturnBenchmarkedtotheSP500IndexGoal",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ffiv_PercentageOfAnnualRevenueGoalToBeAchievedForPerformanceStockGrant": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage Of Annual Revenue Goal To Be Achieved For Performance Stock Grant",
        "label": "Percentage Of Annual Revenue Goal To Be Achieved For Performance Stock Grant",
        "terseLabel": "Percentage Of Annual Revenue Goal To Be Achieved For Performance Stock Grant"
       }
      }
     },
     "localname": "PercentageOfAnnualRevenueGoalToBeAchievedForPerformanceStockGrant",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ffiv_PercentageOfOverAchievementThresholdToWhichGoalsAreEntitled": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage of over-achievement threshold to which the goals are entitled.",
        "label": "Percentage Of Over-Achievement Threshold To Which The Goals Are Entitled",
        "terseLabel": "Percentage Of Over-Achievement Threshold To Which The Goals Are Entitled"
       }
      }
     },
     "localname": "PercentageOfOverAchievementThresholdToWhichGoalsAreEntitled",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ffiv_PercentageOfOverAchievementToWhichAnnualPerformanceBasedVestingCannotExceed": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage Of Over-Achievement To Which Annual Performance Based Vesting Cannot Exceed",
        "label": "Percentage Of Over-Achievement To Which Annual Performance Based Vesting Cannot Exceed",
        "terseLabel": "Percentage Of Over-Achievement To Which Annual Performance Based Vesting Cannot Exceed"
       }
      }
     },
     "localname": "PercentageOfOverAchievementToWhichAnnualPerformanceBasedVestingCannotExceed",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ffiv_PercentageOfOverAchievementToWhichQuarterlyPerformanceBasedVestingCannotExceed": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Over-achievement cap for performance-based awards",
        "label": "Percentage Of Over-Achievement To Which Quarterly Performance Based Vesting Cannot Exceed",
        "terseLabel": "Percentage Of Over-Achievement To Which Quarterly Performance Based Vesting Cannot Exceed"
       }
      }
     },
     "localname": "PercentageOfOverAchievementToWhichQuarterlyPerformanceBasedVestingCannotExceed",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ffiv_PercentageOfQuarterlyEbitdaGoalToBeAchievedForPerformanceStockGrant": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage Of Quarterly Ebitda Goal To Be Achieved For Performance Stock Grant",
        "label": "Percentage Of Quarterly Ebitda Goal To Be Achieved For Performance Stock Grant",
        "terseLabel": "Percentage Of Quarterly Ebitda Goal To Be Achieved For Performance Stock Grant"
       }
      }
     },
     "localname": "PercentageOfQuarterlyEbitdaGoalToBeAchievedForPerformanceStockGrant",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ffiv_PercentageOfQuarterlyPerformanceStockGrantBasedOnAchievingEbitdaGoal": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage of quarterly performance stock grant based on achieving EBITDA goal.",
        "label": "Percentage Of Quarterly Performance Stock Grant Based On Achieving Ebitda Goal",
        "terseLabel": "Percentage Of Quarterly Performance Stock Grant Based On Achieving Ebitda Goal"
       }
      }
     },
     "localname": "PercentageOfQuarterlyPerformanceStockGrantBasedOnAchievingEbitdaGoal",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ffiv_PercentageOfQuarterlyPerformanceStockGrantBasedOnAchievingQuarterlyRevenueGoal": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage of quarterly performance stock grant based on achieving quarterly revenue goal.",
        "label": "Percentage Of Quarterly Performance Stock Grant Based On Achieving Quarterly Revenue Goal",
        "terseLabel": "Percentage Of Quarterly Performance Stock Grant Based On Achieving Quarterly Revenue Goal"
       }
      }
     },
     "localname": "PercentageOfQuarterlyPerformanceStockGrantBasedOnAchievingQuarterlyRevenueGoal",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ffiv_PercentageOfQuarterlyRevenueGoalToBeAchievedForPerformanceStockGrant": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage of quarterly revenue goal to be achieved for performance stock grant.",
        "label": "Percentage Of Quarterly Revenue Goal To Be Achieved For Performance Stock Grant",
        "terseLabel": "Percentage Of Quarterly Revenue Goal To Be Achieved For Performance Stock Grant"
       }
      }
     },
     "localname": "PercentageOfQuarterlyRevenueGoalToBeAchievedForPerformanceStockGrant",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ffiv_RevenuefromContractswithCustomersAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Revenue from Contracts with Customers [Abstract]",
        "label": "Revenue from Contracts with Customers [Abstract]",
        "terseLabel": "Revenue from Contracts with Customers [Abstract]"
       }
      }
     },
     "localname": "RevenuefromContractswithCustomersAbstract",
     "nsuri": "http://www.f5.com/20200930",
     "xbrltype": "stringItemType"
    },
    "ffiv_ScheduleOfEquityBasedAwardIncludingStockOptionsAndRestrictedStockUnitsTableTextBlockTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule of equity based award including stock options and restricted stock units",
        "label": "Schedule Of Equity Based Award Including Stock Options And Restricted Stock Units Table Text Block [Table Text Block]",
        "terseLabel": "Schedule Of Equity Based Awards (Including Stock Options And Restricted Stock Units)"
       }
      }
     },
     "localname": "ScheduleOfEquityBasedAwardIncludingStockOptionsAndRestrictedStockUnitsTableTextBlockTableTextBlock",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ffiv_ScheduleOfEquityBasedAwardsIncludingStockOptionsAndRestrictedStockUnitsLineItems": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule Of Equity Based Awards Including Stock Options And Restricted Stock Units [Line Items]",
        "label": "Schedule Of Equity Based Awards Including Stock Options And Restricted Stock Units [Line Items]",
        "terseLabel": "Schedule Of Equity Based Awards Including Stock Options And Restricted Stock Units [Line Items]"
       }
      }
     },
     "localname": "ScheduleOfEquityBasedAwardsIncludingStockOptionsAndRestrictedStockUnitsLineItems",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfEquityBasedAwardsIncludingStockOptionsAndRestrictedStockUnitsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_ScheduleOfEquityBasedAwardsIncludingStockOptionsAndRestrictedStockUnitsTable": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule Of Equity Based Awards Including Stock Options And Restricted Stock Units [Table]",
        "label": "Schedule Of Equity Based Awards Including Stock Options And Restricted Stock Units [Table]",
        "terseLabel": "Schedule Of Equity Based Awards Including Stock Options And Restricted Stock Units [Table]"
       }
      }
     },
     "localname": "ScheduleOfEquityBasedAwardsIncludingStockOptionsAndRestrictedStockUnitsTable",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfEquityBasedAwardsIncludingStockOptionsAndRestrictedStockUnitsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_ScheduleOfReconciliationOfBeginningAndEndingAmountOfUnrecognizedTaxBenefitsTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule Of Reconciliation Of The Beginning And Ending Amount Of Unrecognized Tax Benefits [Table Text Block]",
        "label": "Schedule Of Reconciliation Of The Beginning And Ending Amount Of Unrecognized Tax Benefits [Table Text Block]",
        "terseLabel": "Schedule Of Reconciliation Of Beginning And Ending Amount Of Unrecognized Tax Benefits"
       }
      }
     },
     "localname": "ScheduleOfReconciliationOfBeginningAndEndingAmountOfUnrecognizedTaxBenefitsTableTextBlock",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "ffiv_ScheduleOfSummaryOfRestrictedStockUnitActivityLineItems": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule Of Summary Of Restricted Stock Unit Activity [Line Items]",
        "label": "Schedule Of Summary Of Restricted Stock Unit Activity [Line Items]",
        "terseLabel": "Schedule Of Summary Of Restricted Stock Unit Activity [Line Items]"
       }
      }
     },
     "localname": "ScheduleOfSummaryOfRestrictedStockUnitActivityLineItems",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_ScheduleOfSummaryOfRestrictedStockUnitActivityTable": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule Of Summary Of Restricted Stock Unit Activity [Table]",
        "label": "Schedule Of Summary Of Restricted Stock Unit Activity [Table]",
        "terseLabel": "Schedule Of Summary Of Restricted Stock Unit Activity [Table]"
       }
      }
     },
     "localname": "ScheduleOfSummaryOfRestrictedStockUnitActivityTable",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_ScheduleOfSummaryOfSignificantAccountingPoliciesLineItems": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule of Summary Of Significant Accounting Policies [Line Items]",
        "label": "Schedule Of Summary Of Significant Accounting Policies [Line Items]",
        "terseLabel": "Schedule Of Summary Of Significant Accounting Policies [Line Items]"
       }
      }
     },
     "localname": "ScheduleOfSummaryOfSignificantAccountingPoliciesLineItems",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_ScheduleOfSummaryOfSignificantAccountingPoliciesTable": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule of Summary of Significant Accounting Policies [Table].",
        "label": "Schedule of Summary of Significant Accounting Policies [Table]",
        "terseLabel": "Schedule of Summary of Significant Accounting Policies [Table]"
       }
      }
     },
     "localname": "ScheduleOfSummaryOfSignificantAccountingPoliciesTable",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_Shape2011SharePlanMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Shape 2011 Share Plan",
        "label": "Shape 2011 Share Plan [Member]",
        "terseLabel": "Shape 2011 Share Plan [Member]"
       }
      }
     },
     "localname": "Shape2011SharePlanMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_ShapeAcquisitionEquityIncentivePlanMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Shape Acquisition Equity Incentive Plan",
        "label": "Shape Acquisition Equity Incentive Plan [Member]",
        "terseLabel": "Shape Acquisition Plan [Member]"
       }
      }
     },
     "localname": "ShapeAcquisitionEquityIncentivePlanMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_ShapeSecurityInc.Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Shape Security Inc. [Member]",
        "label": "Shape Security Inc. [Member]",
        "terseLabel": "Shape Security Inc."
       }
      }
     },
     "localname": "ShapeSecurityInc.Member",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails",
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_ShareBasedCompensationAdditionalSharesReservedNet": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Share Based Compensation Additional Shares Reserved Net",
        "label": "Share Based Compensation Additional Shares Reserved Net",
        "terseLabel": "Additional shares reserved (terminated), net"
       }
      }
     },
     "localname": "ShareBasedCompensationAdditionalSharesReservedNet",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfEquityBasedAwardsIncludingStockOptionsAndRestrictedStockUnitsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "ffiv_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsCancelledInPeriod": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Share-based compensation arrangement by share based payment award equity instruments, cancelled in period.",
        "label": "Share-Based Compensation Arrangement By Share Based Payment Award Equity Instruments, Cancelled In Period",
        "terseLabel": "Awards Available for Grant, Cancelled"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsCancelledInPeriod",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfEquityBasedAwardsIncludingStockOptionsAndRestrictedStockUnitsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "ffiv_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsPerShare": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Per Share",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Per Share",
        "terseLabel": "Fair Value, Per Share"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsPerShare",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "ffiv_ShareBasedCompensationArrangementIndividualStockPurchasesFairValueMaximum": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Share Based Compensation Arrangement Individual Stock Purchases Fair Value Maximum",
        "label": "Share Based Compensation Arrangement Individual Stock Purchases Fair Value Maximum",
        "terseLabel": "Maximum aggregate fair value of stock that an employee may purchase"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementIndividualStockPurchasesFairValueMaximum",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "ffiv_SharebasedCompensationArrangementbySharebasedPaymentAwardNumberofSharesAvailableforGrantRollForward": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant [Roll Forward]",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant [Roll Forward]",
        "terseLabel": "Awards Available\u00a0for Grant"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementbySharebasedPaymentAwardNumberofSharesAvailableforGrantRollForward",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfEquityBasedAwardsIncludingStockOptionsAndRestrictedStockUnitsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_ShareholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Shareholders' Equity [Abstract]",
        "label": "Shareholders' Equity [Abstract]",
        "terseLabel": "Shareholders' Equity [Abstract]"
       }
      }
     },
     "localname": "ShareholdersEquityAbstract",
     "nsuri": "http://www.f5.com/20200930",
     "xbrltype": "stringItemType"
    },
    "ffiv_SoftwareMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Software",
        "label": "Software [Member]",
        "terseLabel": "Software"
       }
      }
     },
     "localname": "SoftwareMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_StandardProductWarrantyPeriod": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Standard Product Warranty Period",
        "label": "Standard Product Warranty Period",
        "terseLabel": "Standard Product Warranty Period"
       }
      }
     },
     "localname": "StandardProductWarrantyPeriod",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "ffiv_StockOptionsAndAwardsVestingRateEntityControlChange": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Stock Options And Awards Vesting Rate Entity Control Change",
        "label": "Stock Options And Awards Vesting Rate Entity Control Change",
        "terseLabel": "Vesting rate of stock options and awards upon certain changes in ownership control"
       }
      }
     },
     "localname": "StockOptionsAndAwardsVestingRateEntityControlChange",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ffiv_SupplementalDisclosuresOfNonCashActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Supplemental disclosures of non-cash activities",
        "label": "Supplemental disclosures of non-cash activities [Abstract]",
        "terseLabel": "Supplemental disclosures of non-cash activities"
       }
      }
     },
     "localname": "SupplementalDisclosuresOfNonCashActivitiesAbstract",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_SystemsAndSoftwareAxis": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Systems and Software",
        "label": "Systems and Software [Axis]",
        "terseLabel": "Systems and Software [Axis]"
       }
      }
     },
     "localname": "SystemsAndSoftwareAxis",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "ffiv_SystemsAndSoftwareDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Systems and Software",
        "label": "Systems and Software [Domain]",
        "terseLabel": "Systems and Software [Domain]"
       }
      }
     },
     "localname": "SystemsAndSoftwareDomain",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_SystemsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Systems",
        "label": "Systems [Member]",
        "terseLabel": "Systems"
       }
      }
     },
     "localname": "SystemsMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_TermLoanFacilityMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Term Loan Facility [Member]",
        "label": "Term Loan Facility [Member]",
        "terseLabel": "Term Loan Facility [Member]"
       }
      }
     },
     "localname": "TermLoanFacilityMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesLongtermDebtMaturitiesDetails",
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_ThresholdPercentageOfTargetedGoalsAboveWhichQuarterlyPerformanceStockGrantIsPaidLinearly": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Threshold percentage of targeted goals above which quarterly performance stock grant is paid linearly",
        "label": "Threshold percentage of targeted goals above which quarterly performance stock grant is paid linearly",
        "terseLabel": "Threshold percentage of targeted goals above which quarterly performance stock grant is paid linearly"
       }
      }
     },
     "localname": "ThresholdPercentageOfTargetedGoalsAboveWhichQuarterlyPerformanceStockGrantIsPaidLinearly",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "ffiv_Traffix2007PlanMemberMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Traffix 2007 Plan [Member] [Member]",
        "label": "Traffix 2007 Plan [Member] [Member]",
        "terseLabel": "Traffix 2007 Plan [Member] [Member]"
       }
      }
     },
     "localname": "Traffix2007PlanMemberMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_Tranche1Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tranche 1",
        "label": "Tranche 1 [Member]",
        "terseLabel": "Tranche 1 [Member]"
       }
      }
     },
     "localname": "Tranche1Member",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_Tranche2Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tranche 2",
        "label": "Tranche 2 [Member]",
        "terseLabel": "Tranche 2 [Member]"
       }
      }
     },
     "localname": "Tranche2Member",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_Tranche3Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tranche 3",
        "label": "Tranche 3 [Member]",
        "terseLabel": "Tranche 3 [Member]"
       }
      }
     },
     "localname": "Tranche3Member",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_TwoThousandElevenEmployeeStockPurchasePlanMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Two Thousand Eleven Employee Stock Purchase Plan [Member]",
        "label": "Two Thousand Eleven Employee Stock Purchase Plan [Member]",
        "terseLabel": "Two Thousand Eleven Employee Stock Purchase Plan [Member]"
       }
      }
     },
     "localname": "TwoThousandElevenEmployeeStockPurchasePlanMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_TwoThousandFourteenEquityIncentivePlanMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Two Thousand Fourteen Equity Incentive Plan [Member]",
        "label": "Two Thousand Fourteen Equity Incentive Plan [Member]",
        "terseLabel": "Two Thousand Fourteen Equity Incentive Plan [Member]"
       }
      }
     },
     "localname": "TwoThousandFourteenEquityIncentivePlanMember",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_WorldwideDistributor1Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Worldwide Distributor 1 [Member]",
        "label": "Worldwide Distributor1 [Member]",
        "terseLabel": "Customer One [Member]"
       }
      }
     },
     "localname": "WorldwideDistributor1Member",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_WorldwideDistributor2Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Worldwide Distributor 2 [Member]",
        "label": "Worldwide Distributor2 [Member]",
        "terseLabel": "Customer Two [Member]"
       }
      }
     },
     "localname": "WorldwideDistributor2Member",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_WorldwideDistributor3Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Worldwide Distributor 3 [Member]",
        "label": "Worldwide Distributor3 [Member]",
        "terseLabel": "Customer Three [Member]"
       }
      }
     },
     "localname": "WorldwideDistributor3Member",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_WorldwideDistributor4Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Worldwide Distributor4 [Member]",
        "label": "Worldwide Distributor4 [Member]",
        "terseLabel": "Customer Four [Member]"
       }
      }
     },
     "localname": "WorldwideDistributor4Member",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "ffiv_WorldwideDistributor5Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Worldwide Distributor5 [Member]",
        "label": "Worldwide Distributor5 [Member]",
        "terseLabel": "Customer Five [Member]"
       }
      }
     },
     "localname": "WorldwideDistributor5Member",
     "nsuri": "http://www.f5.com/20200930",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_AmericasMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Americas [Member]",
        "terseLabel": "Americas [Member]"
       }
      }
     },
     "localname": "AmericasMember",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_AsiaPacificMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Asia Pacific [Member]",
        "terseLabel": "Asia Pacific [Member]"
       }
      }
     },
     "localname": "AsiaPacificMember",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_MajorCustomersAxis": {
     "auth_ref": [
      "r165",
      "r249",
      "r254",
      "r463"
     ],
     "lang": {
      "en-US": {
       "role": {
        "label": "Customer [Axis]",
        "terseLabel": "Customer [Axis]"
       }
      }
     },
     "localname": "MajorCustomersAxis",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_MaximumMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Maximum [Member]",
        "terseLabel": "Maximum"
       }
      }
     },
     "localname": "MaximumMember",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_MinimumMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Minimum [Member]",
        "terseLabel": "Minimum"
       }
      }
     },
     "localname": "MinimumMember",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_NameOfMajorCustomerDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Customer [Domain]",
        "terseLabel": "Customer [Domain]",
        "verboseLabel": "Name of Major Customer [Domain]"
       }
      }
     },
     "localname": "NameOfMajorCustomerDomain",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_OfficeBuildingMember": {
     "auth_ref": [
      "r472",
      "r474"
     ],
     "lang": {
      "en-US": {
       "role": {
        "label": "Office Building [Member]",
        "terseLabel": "Office Building [Member]"
       }
      }
     },
     "localname": "OfficeBuildingMember",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ProductOrServiceAxis": {
     "auth_ref": [
      "r161",
      "r249",
      "r252",
      "r460",
      "r461"
     ],
     "lang": {
      "en-US": {
       "role": {
        "label": "Product and Service [Axis]",
        "terseLabel": "Product and Service [Axis]"
       }
      }
     },
     "localname": "ProductOrServiceAxis",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails",
      "http://www.f5.com/role/SegmentInformationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_ProductsAndServicesDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Product and Service [Domain]",
        "terseLabel": "Product and Service [Domain]"
       }
      }
     },
     "localname": "ProductsAndServicesDomain",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails",
      "http://www.f5.com/role/SegmentInformationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RangeAxis": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Statistical Measurement [Axis]",
        "terseLabel": "Statistical Measurement [Axis]"
       }
      }
     },
     "localname": "RangeAxis",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_RangeMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Statistical Measurement [Domain]",
        "terseLabel": "Statistical Measurement [Domain]"
       }
      }
     },
     "localname": "RangeMember",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_SegmentGeographicalDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Geographical [Domain]",
        "terseLabel": "Segment, Geographical [Domain]"
       }
      }
     },
     "localname": "SegmentGeographicalDomain",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_StatementGeographicalAxis": {
     "auth_ref": [
      "r164",
      "r249",
      "r253",
      "r462",
      "r472",
      "r474"
     ],
     "lang": {
      "en-US": {
       "role": {
        "label": "Geographical [Axis]",
        "terseLabel": "Statement, Geographical [Axis]"
       }
      }
     },
     "localname": "StatementGeographicalAxis",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccountingPoliciesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Accounting Policies [Abstract]",
        "terseLabel": "Accounting Policies [Abstract]"
       }
      }
     },
     "localname": "AccountingPoliciesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccountingStandardsUpdate201409Member": {
     "auth_ref": [
      "r255"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Accounting Standards Update 2014-09 Revenue from Contracts with Customers (Topic 606).",
        "label": "Accounting Standards Update 2014-09 [Member]",
        "terseLabel": "Accounting Standards Update 2014-09 [Member]"
       }
      }
     },
     "localname": "AccountingStandardsUpdate201409Member",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccountingStandardsUpdate201602Member": {
     "auth_ref": [
      "r399"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Accounting Standards Update 2016-02 Leases (Topic 842).",
        "label": "Accounting Standards Update 2016-02 [Member]",
        "terseLabel": "Accounting Standards Update 2016-02 [Member]"
       }
      }
     },
     "localname": "AccountingStandardsUpdate201602Member",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccountsPayableCurrent": {
     "auth_ref": [
      "r41"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
        "label": "Accounts Payable, Current",
        "terseLabel": "Accounts payable"
       }
      }
     },
     "localname": "AccountsPayableCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccountsReceivableMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Due from customers or clients for goods or services that have been delivered or sold.",
        "label": "Accounts Receivable [Member]",
        "terseLabel": "Accounts Receivable [Member]"
       }
      }
     },
     "localname": "AccountsReceivableMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccountsReceivableNetCurrent": {
     "auth_ref": [
      "r3",
      "r28",
      "r167",
      "r168",
      "r250"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.",
        "label": "Accounts Receivable, after Allowance for Credit Loss, Current",
        "verboseLabel": "Accounts receivable, net of allowances of $3,105 and $3,259"
       }
      }
     },
     "localname": "AccountsReceivableNetCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccruedIncomeTaxesNoncurrent": {
     "auth_ref": [
      "r22",
      "r427",
      "r449"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsOtherLongtermLiabilitiesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_OtherLiabilitiesNoncurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Carrying amount as of the balance sheet date of the unpaid sum of the known and estimated amounts payable to satisfy all domestic and foreign income tax obligations due beyond one year or the operating cycle, whichever is longer. Alternate captions include income taxes payable, noncurrent.",
        "label": "Accrued Income Taxes, Noncurrent",
        "terseLabel": "Income taxes payable"
       }
      }
     },
     "localname": "AccruedIncomeTaxesNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsOtherLongtermLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccruedLiabilitiesCurrent": {
     "auth_ref": [
      "r45"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsAccruedLiabilitiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
        "label": "Accrued Liabilities, Current",
        "terseLabel": "Accrued liabilities",
        "totalLabel": "Accrued Liabilities, Current"
       }
      }
     },
     "localname": "AccruedLiabilitiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsAccruedLiabilitiesDetails",
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment": {
     "auth_ref": [
      "r39",
      "r207"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsPropertyandEquipmentDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_PropertyPlantAndEquipmentNet",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.",
        "label": "Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment",
        "negatedLabel": "Accumulated depreciation and amortization",
        "negatedTerseLabel": "Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment"
       }
      }
     },
     "localname": "AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsPropertyandEquipmentDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax": {
     "auth_ref": [
      "r65",
      "r67",
      "r68"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest",
       "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"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeLossNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeMember": {
     "auth_ref": [
      "r64",
      "r68",
      "r71",
      "r367"
     ],
     "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": "AOCI Attributable to Parent [Member]",
        "terseLabel": "Accumulated Other Comprehensive Loss"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife": {
     "auth_ref": [
      "r194"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Acquired Finite-lived Intangible Assets, Weighted Average Useful Life",
        "terseLabel": "Identifiable Intangible Assets Useful Life"
       }
      }
     },
     "localname": "AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails",
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_AdjustmentsForNewAccountingPronouncementsAxis": {
     "auth_ref": [
      "r129"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by new accounting pronouncement.",
        "label": "Adjustments for New Accounting Pronouncements [Axis]",
        "terseLabel": "Adjustments for New Accounting Pronouncements [Axis]"
       }
      }
     },
     "localname": "AdjustmentsForNewAccountingPronouncementsAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity",
      "http://www.f5.com/role/LeasesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]",
        "terseLabel": "Adjustments to reconcile net income to net cash provided by operating activities:"
       }
      }
     },
     "localname": "AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AdvertisingCostsPolicyTextBlock": {
     "auth_ref": [
      "r303"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for advertising cost.",
        "label": "Advertising Cost [Policy Text Block]",
        "verboseLabel": "Advertising"
       }
      }
     },
     "localname": "AdvertisingCostsPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_AdvertisingExpense": {
     "auth_ref": [
      "r304"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line.",
        "label": "Advertising Expense",
        "terseLabel": "Advertising Expense"
       }
      }
     },
     "localname": "AdvertisingExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AllocatedShareBasedCompensationExpense": {
     "auth_ref": [
      "r264",
      "r296",
      "r301"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.",
        "label": "Share-based Payment Arrangement, Expense",
        "terseLabel": "Share-based Payment Arrangement, Expense"
       }
      }
     },
     "localname": "AllocatedShareBasedCompensationExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent": {
     "auth_ref": [
      "r31",
      "r169",
      "r177"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of allowance for credit loss on accounts receivable, classified as current.",
        "label": "Accounts Receivable, Allowance for Credit Loss, Current",
        "terseLabel": "Accounts receivable, allowances"
       }
      }
     },
     "localname": "AllowanceForDoubtfulAccountsReceivableCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AmortizationOfIntangibleAssets": {
     "auth_ref": [
      "r108",
      "r192",
      "r199"
     ],
     "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",
        "terseLabel": "Amortization of Intangible Assets"
       }
      }
     },
     "localname": "AmortizationOfIntangibleAssets",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetImpairmentCharges": {
     "auth_ref": [
      "r108",
      "r205"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 7.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.",
        "label": "Asset Impairment Charges",
        "terseLabel": "Impairment of assets"
       }
      }
     },
     "localname": "AssetImpairmentCharges",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_Assets": {
     "auth_ref": [
      "r158",
      "r426",
      "r448"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Assets [Abstract]",
        "terseLabel": "ASSETS"
       }
      }
     },
     "localname": "AssetsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AssetsCurrent": {
     "auth_ref": [
      "r5",
      "r7",
      "r59"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 7.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.",
        "label": "Assets, Current",
        "totalLabel": "Total current assets"
       }
      }
     },
     "localname": "AssetsCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetsFairValueDisclosure": {
     "auth_ref": [
      "r372"
     ],
     "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": "Assets, Fair Value Disclosure"
       }
      }
     },
     "localname": "AssetsFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecurities": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesAmortizedCost",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.",
        "label": "Available-for-sale Securities",
        "terseLabel": "Available-for-sale securities",
        "verboseLabel": "Fair Value"
       }
      }
     },
     "localname": "AvailableForSaleSecurities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax": {
     "auth_ref": [
      "r171"
     ],
     "calculation": {
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesAmortizedCost",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.",
        "label": "Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax",
        "terseLabel": "Gross Unrealized Gains"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesAmortizedCost",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.",
        "label": "Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax",
        "negatedTerseLabel": "Gross Unrealized Losses"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesAmortizedCost": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.",
        "label": "Available-for-sale Securities, Amortized Cost Basis",
        "totalLabel": "Cost or Amortized Cost"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesAmortizedCost",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.",
        "label": "Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss",
        "negatedTerseLabel": "Available-For-Sale Securities, Continuous Unrealized Loss Position, 12 Months Or Longer, Aggregate Losses Accumulated In Investments"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss": {
     "auth_ref": [
      "r173"
     ],
     "calculation": {
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position.",
        "label": "Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss",
        "negatedTotalLabel": "Available-For-Sale Securities, Continuous Unrealized Loss Position, Aggregate Losses Accumulated In Investments"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.",
        "label": "Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value",
        "totalLabel": "Fair Value, Continuous Loss Position, Unrealized Loss, Total"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for less than twelve months.",
        "label": "Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss",
        "negatedTerseLabel": "Available-For-Sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Aggregate Losses Accumulated In Investments"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months.",
        "label": "Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value",
        "verboseLabel": "Fair Value, Continuous Loss Position, Unrealized Loss, Less Than 12 Months"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for twelve months or longer.",
        "label": "Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value",
        "verboseLabel": "Fair Value, Continuous Loss Position, Unrealized Loss, 12 Months or Greater"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AwardDateAxis": {
     "auth_ref": [
      "r266",
      "r298"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by date or year award under share-based payment arrangement is granted.",
        "label": "Award Date [Axis]",
        "terseLabel": "Award Date [Axis]"
       }
      }
     },
     "localname": "AwardDateAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AwardDateDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Date or year award under share-based payment arrangement is granted.",
        "label": "Award Date [Domain]",
        "terseLabel": "Award Date [Domain]"
       }
      }
     },
     "localname": "AwardDateDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AwardTypeAxis": {
     "auth_ref": [
      "r266",
      "r298"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by type of award under share-based payment arrangement.",
        "label": "Award Type [Axis]",
        "terseLabel": "Award Type [Axis]"
       }
      }
     },
     "localname": "AwardTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfEquityBasedAwardsIncludingStockOptionsAndRestrictedStockUnitsDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "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": "Accounting Principles"
       }
      }
     },
     "localname": "BasisOfAccountingPolicyPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_BusinessAcquisitionAcquireeDomain": {
     "auth_ref": [],
     "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]",
        "terseLabel": "Business Acquisition, Acquiree [Domain]"
       }
      }
     },
     "localname": "BusinessAcquisitionAcquireeDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails",
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_BusinessAcquisitionAxis": {
     "auth_ref": [
      "r348",
      "r349"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by business combination or series of individually immaterial business combinations.",
        "label": "Business Acquisition [Axis]",
        "terseLabel": "Business Acquisition [Axis]"
       }
      }
     },
     "localname": "BusinessAcquisitionAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails",
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_BusinessAcquisitionCostOfAcquiredEntityTransactionCosts": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of direct costs of the business combination including legal, accounting, and other costs incurred to consummate the business acquisition.",
        "label": "Business Acquisition, Transaction Costs",
        "terseLabel": "Transaction Costs"
       }
      }
     },
     "localname": "BusinessAcquisitionCostOfAcquiredEntityTransactionCosts",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessAcquisitionLineItems": {
     "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": "Business Acquisition [Line Items]",
        "terseLabel": "Business Acquisition [Line Items]"
       }
      }
     },
     "localname": "BusinessAcquisitionLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails",
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount": {
     "auth_ref": [
      "r359"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of goodwill arising from a business combination that is expected to be deductible for tax purposes.",
        "label": "Business Acquisition, Goodwill, Expected Tax Deductible Amount",
        "terseLabel": "Tax Deductible Goodwill"
       }
      }
     },
     "localname": "BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationAcquisitionRelatedCosts": {
     "auth_ref": [
      "r347"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.",
        "label": "Business Combination, Acquisition Related Costs",
        "terseLabel": "Business Combination, Acquisition Related Costs"
       }
      }
     },
     "localname": "BusinessCombinationAcquisitionRelatedCosts",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationDisclosureTextBlock": {
     "auth_ref": [
      "r360"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for a business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities. The disclosure may include leverage buyout transactions (as applicable).",
        "label": "Business Combination Disclosure [Text Block]",
        "terseLabel": "Business Combinations"
       }
      }
     },
     "localname": "BusinessCombinationDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinations"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets": {
     "auth_ref": [
      "r351"
     ],
     "calculation": {
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of assets acquired at the acquisition date.",
        "label": "Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets",
        "totalLabel": "Total assets acquired"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents": {
     "auth_ref": [
      "r351"
     ],
     "calculation": {
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets",
       "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, acquired at the acquisition date. 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.",
        "label": "Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents",
        "terseLabel": "Cash and cash equivalents"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther": {
     "auth_ref": [
      "r351"
     ],
     "calculation": {
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of other assets expected to be realized or consumed before one year or the normal operating cycle, if longer, acquired at the acquisition date.",
        "label": "Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other",
        "terseLabel": "Other tangible assets"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables": {
     "auth_ref": [
      "r351"
     ],
     "calculation": {
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount due from customers or clients for goods or services, including trade receivables, that have been delivered or sold in the normal course of business, and amounts due from others, including related parties expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer, acquired at the acquisition date.",
        "label": "Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables",
        "terseLabel": "Accounts receivable"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable": {
     "auth_ref": [
      "r351"
     ],
     "calculation": {
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of liabilities incurred for goods and services received that are used in an entity's business and related party payables, assumed at the acquisition date.",
        "label": "Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable",
        "negatedTerseLabel": "Other assumed liabilities"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue": {
     "auth_ref": [
      "r351"
     ],
     "calculation": {
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of deferred revenue expected to be recognized as such within one year or the normal operating cycle, if longer, assumed at the acquisition date.",
        "label": "Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue",
        "negatedTerseLabel": "Deferred revenue"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets": {
     "auth_ref": [
      "r313",
      "r351"
     ],
     "calculation": {
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of deferred tax asset attributable to deductible temporary differences and carryforwards acquired at the acquisition date.",
        "label": "Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets",
        "terseLabel": "Deferred tax assets"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles": {
     "auth_ref": [
      "r350",
      "r351"
     ],
     "calculation": {
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of identifiable intangible assets recognized as of the acquisition date.",
        "label": "Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles",
        "terseLabel": "Identifiable intangible assets:"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities": {
     "auth_ref": [
      "r351"
     ],
     "calculation": {
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of liabilities assumed at the acquisition date.",
        "label": "Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities",
        "negatedTotalLabel": "Total liabilities assumed"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet": {
     "auth_ref": [
      "r350",
      "r351"
     ],
     "calculation": {
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount recognized as of the acquisition date for the identifiable assets acquired in excess of (less than) the aggregate liabilities assumed.",
        "label": "Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net",
        "totalLabel": "Net assets acquired"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther": {
     "auth_ref": [
      "r351"
     ],
     "calculation": {
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of other liabilities due after one year or the normal operating cycle, if longer, assumed at the acquisition date.",
        "label": "Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other",
        "negatedTerseLabel": "Other assumed liabilities"
       }
      }
     },
     "localname": "BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_BusinessCombinationsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Business Combinations [Abstract]",
        "terseLabel": "Business Combinations"
       }
      }
     },
     "localname": "BusinessCombinationsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_BusinessCombinationsPolicy": {
     "auth_ref": [
      "r118",
      "r346"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for completed business combinations (purchase method, acquisition method or combination of entities under common control). This accounting policy may include a general discussion of the purchase method or acquisition method of accounting (including for example, the treatment accorded contingent consideration, the identification of assets and liabilities, the purchase price allocation process, how the fair values of acquired assets and liabilities are determined) and the entity's specific application thereof. An entity that acquires another entity in a leveraged buyout transaction generally discloses the accounting policy followed by the acquiring entity in determining the basis used to value its interest in the acquired entity, and the rationale for that accounting policy.",
        "label": "Business Combinations Policy [Policy Text Block]",
        "terseLabel": "Business Combinations"
       }
      }
     },
     "localname": "BusinessCombinationsPolicy",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_BusinessExitCosts1": {
     "auth_ref": [
      "r108",
      "r211",
      "r215",
      "r219"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 8.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Includes, but is not limited to, one-time termination benefits, termination of an operating lease or other contract, consolidating or closing facilities, and relocating employees, and termination benefits associated with an ongoing benefit arrangement. Excludes expenses associated with special or contractual termination benefits, a discontinued operation or an asset retirement obligation.",
        "label": "Business Exit Costs",
        "terseLabel": "Non-cash provisions for exit costs"
       }
      }
     },
     "localname": "BusinessExitCosts1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CapitalizedComputerSoftwareGross": {
     "auth_ref": [
      "r476"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsPropertyandEquipmentDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_PropertyPlantAndEquipmentGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before accumulated amortization of capitalized costs for computer software, including but not limited to, acquired and internally developed computer software.",
        "label": "Capitalized Computer Software, Gross",
        "terseLabel": "Capitalized Computer Software, Gross"
       }
      }
     },
     "localname": "CapitalizedComputerSoftwareGross",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsPropertyandEquipmentDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CapitalizedComputerSoftwareImpairments1": {
     "auth_ref": [
      "r475",
      "r477"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of impairment loss from capitalized computer software costs.",
        "label": "Capitalized Computer Software, Impairments",
        "terseLabel": "Capitalized Computer Software, Impairments"
       }
      }
     },
     "localname": "CapitalizedComputerSoftwareImpairments1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsNarrativeDetails",
      "http://www.f5.com/role/FairValueMeasurementsImpairmentofAssetsMeasuredatFairValueonaNonrecurringBasisDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CapitalizedContractCostAmortization": {
     "auth_ref": [
      "r184"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of amortization expense for asset recognized from cost incurred to obtain or fulfill contract with customer.",
        "label": "Capitalized Contract Cost, Amortization",
        "negatedTerseLabel": "Capitalized Contract Cost, Amortization",
        "terseLabel": "Capitalized Contract Cost, Amortization"
       }
      }
     },
     "localname": "CapitalizedContractCostAmortization",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersCapitalizedContractAcquisitionCostsDetails",
      "http://www.f5.com/role/RevenuefromContractswithCustomersNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CapitalizedContractCostAmortizationPeriod": {
     "auth_ref": [
      "r182"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amortization period of cost capitalized in obtaining or fulfilling contract with customer, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.",
        "label": "Capitalized Contract Cost, Amortization Period",
        "terseLabel": "Capitalized Contract Cost, Amortization Period"
       }
      }
     },
     "localname": "CapitalizedContractCostAmortizationPeriod",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_CapitalizedContractCostImpairmentLoss": {
     "auth_ref": [
      "r184"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of impairment loss for asset recognized from cost incurred to obtain or fulfill contract with customer.",
        "label": "Capitalized Contract Cost, Impairment Loss",
        "terseLabel": "Capitalized Contract Cost, Impairment Loss"
       }
      }
     },
     "localname": "CapitalizedContractCostImpairmentLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CapitalizedContractCostNet": {
     "auth_ref": [
      "r183"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer.",
        "label": "Capitalized Contract Cost, Net",
        "periodEndLabel": "Balance, end of year",
        "periodStartLabel": "Balance, beginning of year"
       }
      }
     },
     "localname": "CapitalizedContractCostNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersCapitalizedContractAcquisitionCostsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CapitalizedContractCostNetNoncurrent": {
     "auth_ref": [
      "r183"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsOtherAssetsDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_OtherAssetsNoncurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer; classified as noncurrent.",
        "label": "Capitalized Contract Cost, Net, Noncurrent",
        "terseLabel": "Capitalized contract acquisition costs"
       }
      }
     },
     "localname": "CapitalizedContractCostNetNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsOtherAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CapitalizedContractCostTableTextBlock": {
     "auth_ref": [
      "r185"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of cost capitalized in obtaining or fulfilling contract with customer.",
        "label": "Capitalized Contract Cost [Table Text Block]",
        "terseLabel": "Capitalized Contract Cost"
       }
      }
     },
     "localname": "CapitalizedContractCostTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_CashAndCashEquivalentsAtCarryingValue": {
     "auth_ref": [
      "r1",
      "r35",
      "r110"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsCashCashEquivalentsandRestrictedCashDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents",
       "weight": 1.0
      },
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "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",
        "terseLabel": "Cash and cash equivalents",
        "verboseLabel": "Cash and Cash Equivalents, at Carrying Value"
       }
      }
     },
     "localname": "CashAndCashEquivalentsAtCarryingValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsCashCashEquivalentsandRestrictedCashDetails",
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashAndCashEquivalentsFairValueDisclosure": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Fair value portion 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.",
        "label": "Cash and Cash Equivalents, Fair Value Disclosure",
        "terseLabel": "Cash equivalents, fair value"
       }
      }
     },
     "localname": "CashAndCashEquivalentsFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashAndCashEquivalentsPolicyTextBlock": {
     "auth_ref": [
      "r16",
      "r111",
      "r118"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for cash and cash equivalents, including the policy for determining which items are treated as cash equivalents. Other information that may be disclosed includes (1) the nature of any restrictions on the entity's use of its cash and cash equivalents, (2) whether the entity's cash and cash equivalents are insured or expose the entity to credit risk, (3) the classification of any negative balance accounts (overdrafts), and (4) the carrying basis of cash equivalents (for example, at cost) and whether the carrying amount of cash equivalents approximates fair value.",
        "label": "Cash and Cash Equivalents, Policy [Policy Text Block]",
        "verboseLabel": "Cash, Cash Equivalents and Restricted Cash"
       }
      }
     },
     "localname": "CashAndCashEquivalentsPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents": {
     "auth_ref": [
      "r104",
      "r110",
      "r116"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsCashCashEquivalentsandRestrictedCashDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "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, cash equivalents and restricted cash, end of year",
        "periodStartLabel": "Cash, cash equivalents and restricted cash, beginning of year",
        "totalLabel": "Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents"
       }
      }
     },
     "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsCashCashEquivalentsandRestrictedCashDetails",
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect": {
     "auth_ref": [
      "r104",
      "r387"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "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, cash equivalents and restricted cash"
       }
      }
     },
     "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CertificatesOfDepositMember": {
     "auth_ref": [
      "r441"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Short to medium-term investment available at banks and savings and loan institutions where a customer agrees to lend money to the institution for a certain amount of time and is paid a predetermined rate of interest. Certificates of deposit (CD) are typically Federal Deposit Insurance Corporation (FDIC) insured.",
        "label": "Certificates of Deposit [Member]",
        "terseLabel": "Certificates of Deposit [Member]"
       }
      }
     },
     "localname": "CertificatesOfDepositMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ClassOfTreasuryStockTable": {
     "auth_ref": [
      "r234",
      "r235",
      "r236",
      "r237"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about treasury stock, including, but not limited to, average cost per share, description of share repurchase program, shares repurchased, shares held for each class of treasury stock.",
        "label": "Class of Treasury Stock [Table]",
        "terseLabel": "Class of Treasury Stock [Table]"
       }
      }
     },
     "localname": "ClassOfTreasuryStockTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShareholdersEquityCommonStockRepurchasedandRetiredTableDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CommitmentsAndContingencies": {
     "auth_ref": [
      "r49",
      "r222",
      "r436",
      "r456"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 4.0,
       "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 13)"
       }
      }
     },
     "localname": "CommitmentsAndContingencies",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CommitmentsAndContingenciesDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Commitments and Contingencies Disclosure [Abstract]",
        "terseLabel": "Commitments and Contingencies Disclosure [Abstract]"
       }
      }
     },
     "localname": "CommitmentsAndContingenciesDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_CommitmentsAndContingenciesDisclosureTextBlock": {
     "auth_ref": [
      "r221",
      "r223"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for commitments and contingencies.",
        "label": "Commitments and Contingencies Disclosure [Text Block]",
        "verboseLabel": "Commitments And Contingencies"
       }
      }
     },
     "localname": "CommitmentsAndContingenciesDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CommitmentsAndContingencies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_CommonStockCapitalSharesReservedForFutureIssuance": {
     "auth_ref": [
      "r51"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Aggregate number of common shares reserved for future issuance.",
        "label": "Common Stock, Capital Shares Reserved for Future Issuance",
        "terseLabel": "Common stock reserved for issuance"
       }
      }
     },
     "localname": "CommonStockCapitalSharesReservedForFutureIssuance",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Stock that is subordinate to all other stock of the issuer.",
        "label": "Common Stock [Member]",
        "terseLabel": "Common Stock"
       }
      }
     },
     "localname": "CommonStockMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommonStockNoParValue": {
     "auth_ref": [
      "r27"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Face amount per share of no-par value common stock.",
        "label": "Common Stock, No Par Value",
        "terseLabel": "Common stock, par value (USD per share)"
       }
      }
     },
     "localname": "CommonStockNoParValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets",
      "http://www.f5.com/role/ConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_CommonStockSharesAuthorized": {
     "auth_ref": [
      "r27"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets",
      "http://www.f5.com/role/ConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockSharesIssued": {
     "auth_ref": [
      "r27"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockSharesOutstanding": {
     "auth_ref": [
      "r27",
      "r228"
     ],
     "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",
        "periodEndLabel": "Balance, shares",
        "periodStartLabel": "Balance, shares",
        "terseLabel": "Common stock, shares outstanding"
       }
      }
     },
     "localname": "CommonStockSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets",
      "http://www.f5.com/role/ConsolidatedBalanceSheetsParenthetical",
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockValue": {
     "auth_ref": [
      "r27"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest",
       "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",
        "verboseLabel": "Common stock, no par value; 200,000 shares authorized, 61,099 and 60,367 shares issued and outstanding"
       }
      }
     },
     "localname": "CommonStockValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CompensationAndEmployeeBenefitPlansOtherThanShareBasedCompensationTextBlock": {
     "auth_ref": [
      "r257",
      "r258",
      "r262"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure of an entity's employee compensation and benefit plans, excluding share-based compensation and 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, life insurance, severance, health care, unemployment and other benefit plans.",
        "label": "Compensation and Employee Benefit Plans, Other than Share-based Compensation [Text Block]",
        "terseLabel": "Employee Benefit Plans"
       }
      }
     },
     "localname": "CompensationAndEmployeeBenefitPlansOtherThanShareBasedCompensationTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/EmployeeBenefitPlans"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest": {
     "auth_ref": [
      "r74",
      "r76",
      "r363",
      "r369"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement": {
       "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. Excludes changes in equity resulting from investments by owners and distributions to owners.",
        "label": "Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest",
        "totalLabel": "Comprehensive income"
       }
      }
     },
     "localname": "ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ComprehensiveIncomePolicyPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for comprehensive income.",
        "label": "Comprehensive Income, Policy [Policy Text Block]",
        "terseLabel": "Comprehensive Income"
       }
      }
     },
     "localname": "ComprehensiveIncomePolicyPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ConcentrationRiskBenchmarkDomain": {
     "auth_ref": [
      "r149",
      "r150",
      "r384",
      "r385"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The denominator in a calculation of a disclosed concentration risk percentage.",
        "label": "Concentration Risk Benchmark [Domain]",
        "terseLabel": "Concentration Risk Benchmark [Domain]"
       }
      }
     },
     "localname": "ConcentrationRiskBenchmarkDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ConcentrationRiskByBenchmarkAxis": {
     "auth_ref": [
      "r149",
      "r150",
      "r384",
      "r385",
      "r466"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by benchmark of concentration risk.",
        "label": "Concentration Risk Benchmark [Axis]",
        "terseLabel": "Concentration Risk Benchmark [Axis]"
       }
      }
     },
     "localname": "ConcentrationRiskByBenchmarkAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ConcentrationRiskByTypeAxis": {
     "auth_ref": [
      "r149",
      "r150",
      "r384",
      "r385",
      "r466"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by type of concentration risk, for example, but not limited to, asset, liability, net assets, geographic, customer, employees, supplier, lender.",
        "label": "Concentration Risk Type [Axis]",
        "terseLabel": "Concentration Risk Type [Axis]"
       }
      }
     },
     "localname": "ConcentrationRiskByTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ConcentrationRiskCreditRisk": {
     "auth_ref": [
      "r145",
      "r444"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for credit risk.",
        "label": "Concentration Risk, Credit Risk, Policy [Policy Text Block]",
        "terseLabel": "Concentration Of Credit Risk"
       }
      }
     },
     "localname": "ConcentrationRiskCreditRisk",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ConcentrationRiskPercentage1": {
     "auth_ref": [
      "r149",
      "r150",
      "r384",
      "r385"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the \"benchmark\" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.",
        "label": "Concentration Risk, Percentage",
        "terseLabel": "Concentration risk percentage"
       }
      }
     },
     "localname": "ConcentrationRiskPercentage1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_ConcentrationRiskTypeDomain": {
     "auth_ref": [
      "r149",
      "r150",
      "r384",
      "r385"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "For an entity that discloses a concentration risk as a percentage of some financial balance or benchmark, identifies the type (for example, asset, liability, net assets, geographic, customer, employees, supplier, lender) of the concentration.",
        "label": "Concentration Risk Type [Domain]",
        "terseLabel": "Concentration Risk Type [Domain]"
       }
      }
     },
     "localname": "ConcentrationRiskTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ConsolidationPolicyTextBlock": {
     "auth_ref": [
      "r118",
      "r365",
      "r370",
      "r371"
     ],
     "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]",
        "verboseLabel": "Principles Of Consolidation"
       }
      }
     },
     "localname": "ConsolidationPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock": {
     "auth_ref": [
      "r245"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of contract balances and changes in contract balances.",
        "label": "Contract with Customer, Asset and Liability [Table Text Block]",
        "terseLabel": "Contract with Customer, Asset and Liability"
       }
      }
     },
     "localname": "ContractWithCustomerAssetAndLiabilityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ContractWithCustomerAssetCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice": {
     "auth_ref": [
      "r243"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from change in estimate of transaction price which increases (decreases) right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time. Includes, but is not limited to, change in assessment of whether estimate of variable consideration is constrained.",
        "label": "Contract with Customer, Asset, Cumulative Catch-up Adjustment to Revenue, Change in Estimate of Transaction Price",
        "terseLabel": "Impacts from adoption of ASC 606"
       }
      }
     },
     "localname": "ContractWithCustomerAssetCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersContractAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerAssetIncreaseDecreaseForContractAcquiredInBusinessCombination": {
     "auth_ref": [
      "r242"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase (decrease) in right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, from business combination.",
        "label": "Contract with Customer, Asset, Increase (Decrease) for Contract Acquired in Business Combination",
        "terseLabel": "Contract assets acquired through the purchase of Shape"
       }
      }
     },
     "localname": "ContractWithCustomerAssetIncreaseDecreaseForContractAcquiredInBusinessCombination",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersContractAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerAssetNet": {
     "auth_ref": [
      "r239",
      "r241",
      "r250"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.",
        "label": "Contract with Customer, Asset, after Allowance for Credit Loss",
        "periodEndLabel": "Balance, end of year",
        "periodStartLabel": "Balance, beginning of year"
       }
      }
     },
     "localname": "ContractWithCustomerAssetNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersContractAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerAssetNetCurrent": {
     "auth_ref": [
      "r239",
      "r241",
      "r250"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsOtherCurrentAssetsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_OtherAssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, classified as current.",
        "label": "Contract with Customer, Asset, Net, Current",
        "terseLabel": "Contract assets"
       }
      }
     },
     "localname": "ContractWithCustomerAssetNetCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsOtherCurrentAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerAssetNetNoncurrent": {
     "auth_ref": [
      "r239",
      "r241",
      "r250"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsOtherAssetsDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_OtherAssetsNoncurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, classified as noncurrent.",
        "label": "Contract with Customer, Asset, Net, Noncurrent",
        "terseLabel": "Contract assets"
       }
      }
     },
     "localname": "ContractWithCustomerAssetNetNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsOtherAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerAssetReclassifiedToReceivable": {
     "auth_ref": [
      "r244"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of decrease in right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time from transfer to receivable due to right to consideration becoming unconditional.",
        "label": "Contract with Customer, Asset, Reclassified to Receivable",
        "terseLabel": "Contract assets reclassified to accounts receivable"
       }
      }
     },
     "localname": "ContractWithCustomerAssetReclassifiedToReceivable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersContractAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerLiability": {
     "auth_ref": [
      "r239",
      "r240",
      "r250"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.",
        "label": "Contract with Customer, Liability",
        "periodEndLabel": "Balance, end of year",
        "periodStartLabel": "Balance, beginning of year"
       }
      }
     },
     "localname": "ContractWithCustomerLiability",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersContractAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice": {
     "auth_ref": [
      "r243"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from change in estimate of transaction price which (increases) decreases obligation to transfer good or service to customer for which consideration from customer has been received or is due. Includes, but is not limited to, change in assessment of whether estimate of variable consideration is constrained.",
        "label": "Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Change in Estimate of Transaction Price",
        "terseLabel": "Impacts from adoption of ASC 606"
       }
      }
     },
     "localname": "ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersContractAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerLiabilityCurrent": {
     "auth_ref": [
      "r239",
      "r240",
      "r250"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current.",
        "label": "Contract with Customer, Liability, Current",
        "verboseLabel": "Deferred revenue"
       }
      }
     },
     "localname": "ContractWithCustomerLiabilityCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination": {
     "auth_ref": [
      "r242"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase (decrease) in obligation to transfer good or service to customer for which consideration from customer has been received or is due, from business combination.",
        "label": "Contract with Customer, Liability, Increase (Decrease) for Contract Acquired in Business Combination",
        "terseLabel": "Amounts acquired through the purchase of Shape"
       }
      }
     },
     "localname": "ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersContractAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerLiabilityNoncurrent": {
     "auth_ref": [
      "r239",
      "r240",
      "r250"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_LiabilitiesNoncurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as noncurrent.",
        "label": "Contract with Customer, Liability, Noncurrent",
        "terseLabel": "Deferred revenue, long-term"
       }
      }
     },
     "localname": "ContractWithCustomerLiabilityNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerLiabilityRevenueRecognized": {
     "auth_ref": [
      "r251"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.",
        "label": "Contract with Customer, Liability, Revenue Recognized",
        "terseLabel": "Revenues recognized related to the opening balance of deferred revenue"
       }
      }
     },
     "localname": "ContractWithCustomerLiabilityRevenueRecognized",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersContractAssetsandLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CorporateDebtSecuritiesMember": {
     "auth_ref": [
      "r259",
      "r261",
      "r464"
     ],
     "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 Debt Securities [Member]",
        "terseLabel": "Corporate Bonds And Notes [Member]",
        "verboseLabel": "Corporate Debt Securities [Member]"
       }
      }
     },
     "localname": "CorporateDebtSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CostOfGoodsAndServicesSold": {
     "auth_ref": [
      "r84"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedIncomeStatements": {
       "order": 1.0,
       "parentTag": "us-gaap_GrossProfit",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.",
        "label": "Cost of Goods and Services Sold",
        "terseLabel": "Cost of net revenues",
        "verboseLabel": "Cost of net revenues"
       }
      }
     },
     "localname": "CostOfGoodsAndServicesSold",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CostOfRevenueAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Cost of Revenue [Abstract]",
        "terseLabel": "Cost of net revenues"
       }
      }
     },
     "localname": "CostOfRevenueAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CreditFacilityAxis": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by type of credit facility. Credit facilities provide capital to borrowers without the need to structure a loan for each borrowing.",
        "label": "Credit Facility [Axis]",
        "terseLabel": "Credit Facility [Axis]"
       }
      }
     },
     "localname": "CreditFacilityAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesLongtermDebtMaturitiesDetails",
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CreditFacilityDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Type of credit facility. Credit facilities provide capital to borrowers without the need to structure a loan for each borrowing.",
        "label": "Credit Facility [Domain]",
        "terseLabel": "Credit Facility [Domain]"
       }
      }
     },
     "localname": "CreditFacilityDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesLongtermDebtMaturitiesDetails",
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.",
        "label": "Cumulative Effect of New Accounting Principle in Period of Adoption",
        "terseLabel": "Cumulative effect adjustment from adoption of ASC 606"
       }
      }
     },
     "localname": "CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CurrentFederalTaxExpenseBenefit": {
     "auth_ref": [
      "r123",
      "r337",
      "r341"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_CurrentIncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations.",
        "label": "Current Federal Tax Expense (Benefit)",
        "verboseLabel": "Current, U.S. federal"
       }
      }
     },
     "localname": "CurrentFederalTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CurrentForeignTaxExpenseBenefit": {
     "auth_ref": [
      "r126",
      "r339"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_CurrentIncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of current foreign income tax expense (benefit) pertaining to income (loss) from continuing operations.",
        "label": "Current Foreign Tax Expense (Benefit)",
        "verboseLabel": "Current, Foreign"
       }
      }
     },
     "localname": "CurrentForeignTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CurrentIncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r123",
      "r337",
      "r341"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.",
        "label": "Current Income Tax Expense (Benefit)",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "CurrentIncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CurrentStateAndLocalTaxExpenseBenefit": {
     "auth_ref": [
      "r123",
      "r337",
      "r341"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_CurrentIncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of current state and local tax expense (benefit) pertaining to income (loss) from continuing operations.",
        "label": "Current State and Local Tax Expense (Benefit)",
        "verboseLabel": "Current, State"
       }
      }
     },
     "localname": "CurrentStateAndLocalTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CustomerRelationshipsMember": {
     "auth_ref": [
      "r355"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Customer relationship that exists between an entity and its customer, for example, but not limited to, tenant relationships.",
        "label": "Customer Relationships [Member]",
        "terseLabel": "Customer Relationships"
       }
      }
     },
     "localname": "CustomerRelationshipsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails",
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails",
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DebtDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Debt Disclosure [Abstract]"
       }
      }
     },
     "localname": "DebtDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtDisclosureTextBlock": {
     "auth_ref": [
      "r227"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.",
        "label": "Debt Disclosure [Text Block]",
        "terseLabel": "Debt Facilities"
       }
      }
     },
     "localname": "DebtDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilities"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DebtInstrumentBasisSpreadOnVariableRate1": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage points added to the reference rate to compute the variable rate on the debt instrument.",
        "label": "Debt Instrument, Basis Spread on Variable Rate",
        "terseLabel": "Basis Spread on Variable Rate"
       }
      }
     },
     "localname": "DebtInstrumentBasisSpreadOnVariableRate1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DebtInstrumentLineItems": {
     "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 Instrument [Line Items]",
        "terseLabel": "Debt Instrument [Line Items]"
       }
      }
     },
     "localname": "DebtInstrumentLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesLongtermDebtMaturitiesDetails",
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtInstrumentRedemptionPricePercentage": {
     "auth_ref": [
      "r442"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.",
        "label": "Debt Instrument, Redemption Price, Percentage",
        "terseLabel": "Redemption Percentage"
       }
      }
     },
     "localname": "DebtInstrumentRedemptionPricePercentage",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DebtInstrumentTable": {
     "auth_ref": [
      "r47",
      "r124",
      "r229",
      "r230",
      "r231",
      "r232",
      "r390",
      "r391",
      "r393",
      "r443"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A table or schedule providing information pertaining to long-term debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the company, if longer.",
        "label": "Schedule of Long-term Debt Instruments [Table]",
        "terseLabel": "Schedule of Long-term Debt Instruments [Table]"
       }
      }
     },
     "localname": "DebtInstrumentTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesLongtermDebtMaturitiesDetails",
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DeferredFederalIncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r123",
      "r338",
      "r341"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_DeferredIncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of deferred federal income tax expense (benefit) pertaining to income (loss) from continuing operations.",
        "label": "Deferred Federal Income Tax Expense (Benefit)",
        "verboseLabel": "Deferred, U.S. federal"
       }
      }
     },
     "localname": "DeferredFederalIncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredFinanceCostsGross": {
     "auth_ref": [
      "r392"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.",
        "label": "Debt Issuance Costs, Gross",
        "terseLabel": "Debt Issuance Costs"
       }
      }
     },
     "localname": "DeferredFinanceCostsGross",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredForeignIncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r123",
      "r338",
      "r341"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_DeferredIncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of deferred foreign income tax expense (benefit) pertaining to income (loss) from continuing operations.",
        "label": "Deferred Foreign Income Tax Expense (Benefit)",
        "verboseLabel": "Deferred, Foreign"
       }
      }
     },
     "localname": "DeferredForeignIncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredIncomeTaxAssetsNet": {
     "auth_ref": [
      "r331"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 4.0,
       "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 Income Tax Assets, Net",
        "terseLabel": "Deferred tax assets"
       }
      }
     },
     "localname": "DeferredIncomeTaxAssetsNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredIncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r108",
      "r123",
      "r338",
      "r341"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.",
        "label": "Deferred Income Tax Expense (Benefit)",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "DeferredIncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredIncomeTaxLiabilities": {
     "auth_ref": [
      "r24",
      "r25",
      "r327",
      "r428",
      "r445"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_DeferredTaxAssetsLiabilitiesNet",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of deferred tax liability attributable to taxable temporary differences.",
        "label": "Deferred Tax Liabilities, Gross",
        "negatedTotalLabel": "Total deferred tax liabilities"
       }
      }
     },
     "localname": "DeferredIncomeTaxLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredIncomeTaxLiabilitiesNet": {
     "auth_ref": [
      "r314",
      "r331"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_LiabilitiesNoncurrent",
       "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 liabilities"
       }
      }
     },
     "localname": "DeferredIncomeTaxLiabilitiesNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredIncomeTaxesAndTaxCredits": {
     "auth_ref": [
      "r109"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 6.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of deferred income tax expense (benefit) and income tax credits.",
        "label": "Deferred Income Taxes and Tax Credits",
        "terseLabel": "Deferred income taxes"
       }
      }
     },
     "localname": "DeferredIncomeTaxesAndTaxCredits",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredRentCreditNoncurrent": {
     "auth_ref": [
      "r50",
      "r395"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsOtherLongtermLiabilitiesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_OtherLiabilitiesNoncurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "For a classified balance sheet, the cumulative difference between the rental income or payments required by a lease agreement and the rental income or expense recognized on a straight-line basis, or other systematic and rational basis more representative of the time pattern in which use or benefit is granted or derived from the leased property, expected to be recognized in income or expense, by the lessor or lessee, respectively, more than one year after the balance sheet date.",
        "label": "Deferred Rent Credit, Noncurrent",
        "terseLabel": "Deferred rent"
       }
      }
     },
     "localname": "DeferredRentCreditNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsOtherLongtermLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r123",
      "r338",
      "r341"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_DeferredIncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of deferred state and local tax expense (benefit) pertaining to income (loss) from continuing operations.",
        "label": "Deferred State and Local Income Tax Expense (Benefit)",
        "verboseLabel": "Deferred, State"
       }
      }
     },
     "localname": "DeferredStateAndLocalIncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsDeferredIncome": {
     "auth_ref": [
      "r308",
      "r335",
      "r336"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_DeferredTaxAssetsGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from deferred income.",
        "label": "Deferred Tax Assets, Deferred Income",
        "terseLabel": "Deferred revenue"
       }
      }
     },
     "localname": "DeferredTaxAssetsDeferredIncome",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsGross": {
     "auth_ref": [
      "r328"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_DeferredTaxAssetsLiabilitiesNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.",
        "label": "Deferred Tax Assets, Gross",
        "totalLabel": "Total deferred tax assets before deferred liabilities"
       }
      }
     },
     "localname": "DeferredTaxAssetsGross",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsLiabilitiesNet": {
     "auth_ref": [
      "r331"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "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, without jurisdictional netting.",
        "label": "Deferred Tax Assets, Net",
        "totalLabel": "Net deferred tax assets"
       }
      }
     },
     "localname": "DeferredTaxAssetsLiabilitiesNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsNet": {
     "auth_ref": [
      "r329"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.",
        "label": "Deferred Tax Assets, Net of Valuation Allowance",
        "totalLabel": "Deferred tax assets, net of valuation allowance"
       }
      }
     },
     "localname": "DeferredTaxAssetsNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsOperatingLossCarryforwards": {
     "auth_ref": [
      "r306",
      "r335",
      "r336"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_DeferredTaxAssetsGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards.",
        "label": "Deferred Tax Assets, Operating Loss Carryforwards",
        "terseLabel": "Deferred Tax Assets, Operating Loss Carryforwards",
        "verboseLabel": "Net operating loss carry-forwards"
       }
      }
     },
     "localname": "DeferredTaxAssetsOperatingLossCarryforwards",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails",
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards that are not subject to expiration dates.",
        "label": "Deferred Tax Assets, Operating Loss Carryforwards, Not Subject to Expiration",
        "verboseLabel": "Operating loss carry-forwards, net"
       }
      }
     },
     "localname": "DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards that are subject to expiration dates.",
        "label": "Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration",
        "terseLabel": "Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration"
       }
      }
     },
     "localname": "DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsOther": {
     "auth_ref": [
      "r308",
      "r335",
      "r336"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": 8.0,
       "parentTag": "us-gaap_DeferredTaxAssetsGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other.",
        "label": "Deferred Tax Assets, Other",
        "terseLabel": "Depreciation"
       }
      }
     },
     "localname": "DeferredTaxAssetsOther",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsTaxCreditCarryforwards": {
     "auth_ref": [
      "r333",
      "r335",
      "r336"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_DeferredTaxAssetsGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, before allocation of a valuation allowances, of deferred tax assets attributable to deductible tax credit carryforwards including, but not limited to, research, foreign, general business, alternative minimum tax, and other deductible tax credit carryforwards.",
        "label": "Deferred Tax Assets, Tax Credit Carryforwards",
        "terseLabel": "Deferred Tax Assets, Tax Credit Carryforwards",
        "verboseLabel": "Tax credit carryforwards"
       }
      }
     },
     "localname": "DeferredTaxAssetsTaxCreditCarryforwards",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails",
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits": {
     "auth_ref": [
      "r306",
      "r335",
      "r336"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_DeferredTaxAssetsGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences from employee benefits, classified as other.",
        "label": "Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits",
        "verboseLabel": "Accrued compensation and benefits"
       }
      }
     },
     "localname": "DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost": {
     "auth_ref": [
      "r306",
      "r335",
      "r336"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": 7.0,
       "parentTag": "us-gaap_DeferredTaxAssetsGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation.",
        "label": "Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost",
        "terseLabel": "Stock-based compensation"
       }
      }
     },
     "localname": "DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsDeferredRent": {
     "auth_ref": [
      "r306",
      "r335",
      "r336"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_DeferredTaxAssetsGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from deferred rent.",
        "label": "Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Deferred Rent",
        "terseLabel": "Lease liabilities"
       }
      }
     },
     "localname": "DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsDeferredRent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsOther": {
     "auth_ref": [
      "r306",
      "r335",
      "r336"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_DeferredTaxAssetsGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences from reserves and accruals, classified as other.",
        "label": "Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Other",
        "verboseLabel": "Other accruals and reserves"
       }
      }
     },
     "localname": "DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsOther",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxAssetsValuationAllowance": {
     "auth_ref": [
      "r330"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_DeferredTaxAssetsNet",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.",
        "label": "Deferred Tax Assets, Valuation Allowance",
        "negatedLabel": "Valuation allowance"
       }
      }
     },
     "localname": "DeferredTaxAssetsValuationAllowance",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxLiabilitiesDeferredExpenseOtherCapitalizedCosts": {
     "auth_ref": [
      "r307",
      "r335",
      "r336"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_DeferredIncomeTaxLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of deferred tax liability attributable to taxable temporary differences from capitalized costs classified as other.",
        "label": "Deferred Tax Liabilities, Deferred Expense, Other Capitalized Costs",
        "negatedTerseLabel": "Deferred Tax Liabilities, Deferred Expense, Other Capitalized Costs"
       }
      }
     },
     "localname": "DeferredTaxLiabilitiesDeferredExpenseOtherCapitalizedCosts",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxLiabilitiesDeferredExpenseReservesAndAccruals": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_DeferredIncomeTaxLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of deferred tax liability attributable to taxable temporary differences from reserves and accruals.",
        "label": "Deferred Tax Liabilities, Deferred Expense, Reserves and Accruals",
        "negatedTerseLabel": "Deferred Tax Liabilities, Deferred Expense, Reserves and Accruals"
       }
      }
     },
     "localname": "DeferredTaxLiabilitiesDeferredExpenseReservesAndAccruals",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets": {
     "auth_ref": [
      "r308",
      "r335",
      "r336"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_DeferredIncomeTaxLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of deferred tax liability attributable to taxable temporary differences from intangible assets other than goodwill.",
        "label": "Deferred Tax Liabilities, Intangible Assets",
        "negatedLabel": "Purchased intangibles"
       }
      }
     },
     "localname": "DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DeferredTaxLiabilitiesOther": {
     "auth_ref": [
      "r308",
      "r335",
      "r336"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_DeferredIncomeTaxLiabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of deferred tax liability attributable to taxable temporary differences classified as other.",
        "label": "Deferred Tax Liabilities, Other",
        "negatedLabel": "Depreciation"
       }
      }
     },
     "localname": "DeferredTaxLiabilitiesOther",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfTaxEffectsToDeferredTaxAssetsAndLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]",
        "terseLabel": "Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]"
       }
      }
     },
     "localname": "DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of discretionary contributions made by an employer to a defined contribution plan.",
        "label": "Defined Contribution Plan, Employer Discretionary Contribution Amount",
        "terseLabel": "Contributions by the Company to the plan"
       }
      }
     },
     "localname": "DefinedContributionPlanEmployerDiscretionaryContributionAmount",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/EmployeeBenefitPlansDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DepreciationDepletionAndAmortization": {
     "auth_ref": [
      "r108",
      "r156"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.",
        "label": "Depreciation, Depletion and Amortization",
        "terseLabel": "Depreciation and amortization"
       }
      }
     },
     "localname": "DepreciationDepletionAndAmortization",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsNarrativeDetails",
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DevelopedTechnologyRightsMember": {
     "auth_ref": [
      "r356"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Rights to developed technology, which can include the right to develop, use, market, sell, or offer for sale products, compounds, or intellectual property.",
        "label": "Developed Technology Rights [Member]",
        "terseLabel": "Developed Technology Rights"
       }
      }
     },
     "localname": "DevelopedTechnologyRightsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails",
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails",
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock": {
     "auth_ref": [
      "r302"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for share-based payment arrangement.",
        "label": "Share-based Payment Arrangement [Text Block]",
        "terseLabel": "Stock-Based Compensation"
       }
      }
     },
     "localname": "DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensation"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Share-based Payment Arrangement [Abstract]"
       }
      }
     },
     "localname": "DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_DomesticCountryMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Designated tax department of the government that is entitled to levy and collect income taxes from the entity in its country of domicile.",
        "label": "Domestic Tax Authority [Member]",
        "terseLabel": "Domestic Tax Authority [Member]"
       }
      }
     },
     "localname": "DomesticCountryMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_EMEAMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Regions of Europe, Middle East and Africa.",
        "label": "EMEA [Member]",
        "terseLabel": "EMEA [Member]"
       }
      }
     },
     "localname": "EMEAMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_EarningsPerShareBasic": {
     "auth_ref": [
      "r80",
      "r130",
      "r133",
      "r134",
      "r135",
      "r136",
      "r138",
      "r439",
      "r458"
     ],
     "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": "Net income per share - basic (USD per share)",
        "verboseLabel": "Basic net income per share (USD per share)"
       }
      }
     },
     "localname": "EarningsPerShareBasic",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/NetIncomePerShareDetails",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfComputationOfBasicAndDilutedNetIncomePerShareDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_EarningsPerShareDiluted": {
     "auth_ref": [
      "r80",
      "r130",
      "r133",
      "r134",
      "r135",
      "r136",
      "r138",
      "r439",
      "r458"
     ],
     "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": "Net income per share - diluted (USD per share)",
        "verboseLabel": "Diluted net income per share (USD per share)"
       }
      }
     },
     "localname": "EarningsPerShareDiluted",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/NetIncomePerShareDetails",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfComputationOfBasicAndDilutedNetIncomePerShareDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_EarningsPerShareTextBlock": {
     "auth_ref": [
      "r139"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for earnings per share.",
        "label": "Earnings Per Share [Text Block]",
        "terseLabel": "Net Income Per Share"
       }
      }
     },
     "localname": "EarningsPerShareTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/NetIncomePerShare"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents": {
     "auth_ref": [
      "r387"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase (decrease) from the effect of exchange rate changes on cash and cash equivalent balances held in foreign currencies.",
        "label": "Effect of Exchange Rate on Cash and Cash Equivalents",
        "terseLabel": "Effect of exchange rate changes on cash, cash equivalents and restricted cash"
       }
      }
     },
     "localname": "EffectOfExchangeRateOnCashAndCashEquivalents",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate": {
     "auth_ref": [
      "r315",
      "r316",
      "r340"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage of domestic federal statutory tax rate applicable to pretax income (loss).",
        "label": "Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent",
        "terseLabel": "Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent"
       }
      }
     },
     "localname": "EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_EmployeeRelatedLiabilitiesCurrent": {
     "auth_ref": [
      "r45"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsAccruedLiabilitiesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_AccruedLiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
        "label": "Employee-related Liabilities, Current",
        "terseLabel": "Payroll and benefits"
       }
      }
     },
     "localname": "EmployeeRelatedLiabilitiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsAccruedLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized": {
     "auth_ref": [
      "r297"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cost not yet recognized for nonvested award under share-based payment arrangement.",
        "label": "Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount",
        "terseLabel": "Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1": {
     "auth_ref": [
      "r297"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Weighted-average period over which cost not yet recognized is expected to be recognized for 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 Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition",
        "terseLabel": "Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense": {
     "auth_ref": [
      "r296"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of tax benefit for recognition of expense of award under share-based payment arrangement.",
        "label": "Share-based Payment Arrangement, Expense, Tax Benefit",
        "terseLabel": "Share-based Payment Arrangement, Expense, Tax Benefit"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeStockOptionMember": {
     "auth_ref": [
      "r295"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Share-based payment arrangement granting right, subject to vesting and other restrictions, to purchase or sell certain number of shares at predetermined price for specified period of time.",
        "label": "Share-based Payment Arrangement, Option [Member]",
        "terseLabel": "Share-based Payment Arrangement, Option [Member]"
       }
      }
     },
     "localname": "EmployeeStockOptionMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_EquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Equity [Abstract]"
       }
      }
     },
     "localname": "EquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_EquityClassOfTreasuryStockLineItems": {
     "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": "Equity, Class of Treasury Stock [Line Items]",
        "terseLabel": "Equity, Class of Treasury Stock [Line Items]"
       }
      }
     },
     "localname": "EquityClassOfTreasuryStockLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShareholdersEquityCommonStockRepurchasedandRetiredTableDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_EquityComponentDomain": {
     "auth_ref": [
      "r228"
     ],
     "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]",
        "terseLabel": "Equity Component [Domain]"
       }
      }
     },
     "localname": "EquityComponentDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable": {
     "auth_ref": [
      "r372",
      "r373",
      "r374",
      "r379"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about asset and liability measured at fair value on recurring and nonrecurring basis.",
        "label": "Fair Value, Recurring and Nonrecurring [Table]",
        "terseLabel": "Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table]"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems": {
     "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 Measurement Inputs and Valuation Techniques [Line Items]",
        "terseLabel": "Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueAssetsMeasuredOnRecurringBasisTextBlock": {
     "auth_ref": [
      "r372",
      "r373"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of assets, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, by class 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": "Fair Value, Assets Measured on Recurring Basis [Table Text Block]",
        "terseLabel": "Schedule Of Financial Assets Measured At Fair Value on A Recurring Basis"
       }
      }
     },
     "localname": "FairValueAssetsMeasuredOnRecurringBasisTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain": {
     "auth_ref": [
      "r377"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Class of asset.",
        "label": "Asset Class [Domain]",
        "terseLabel": "Asset Class [Domain]"
       }
      }
     },
     "localname": "FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueByAssetClassAxis": {
     "auth_ref": [
      "r372",
      "r379"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by class of asset.",
        "label": "Asset Class [Axis]",
        "terseLabel": "Asset Class [Axis]"
       }
      }
     },
     "localname": "FairValueByAssetClassAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByFairValueHierarchyLevelAxis": {
     "auth_ref": [
      "r259",
      "r260",
      "r261",
      "r373",
      "r419"
     ],
     "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 and NAV [Axis]",
        "terseLabel": "Fair Value Hierarchy and NAV [Axis]"
       }
      }
     },
     "localname": "FairValueByFairValueHierarchyLevelAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByMeasurementFrequencyAxis": {
     "auth_ref": [
      "r372",
      "r373",
      "r375",
      "r376",
      "r381"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by measurement frequency.",
        "label": "Measurement Frequency [Axis]",
        "terseLabel": "Measurement Frequency [Axis]"
       }
      }
     },
     "localname": "FairValueByMeasurementFrequencyAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Fair Value Disclosures [Abstract]",
        "terseLabel": "Fair Value Disclosures [Abstract]"
       }
      }
     },
     "localname": "FairValueDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueDisclosuresTextBlock": {
     "auth_ref": [
      "r378"
     ],
     "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]",
        "verboseLabel": "Fair Value Measurements"
       }
      }
     },
     "localname": "FairValueDisclosuresTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurements"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueInputsLevel1Member": {
     "auth_ref": [
      "r259",
      "r260",
      "r261",
      "r373",
      "r420"
     ],
     "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": "Fair Value, Inputs, Level 1 [Member]",
        "terseLabel": "Quoted Prices In Active Markets For Identical Securities (Level 1) [Member]"
       }
      }
     },
     "localname": "FairValueInputsLevel1Member",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueInputsLevel2Member": {
     "auth_ref": [
      "r259",
      "r260",
      "r261",
      "r373",
      "r421"
     ],
     "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": "Fair Value, Inputs, Level 2 [Member]",
        "terseLabel": "Significant Other Observable Inputs (Level 2) [Member]"
       }
      }
     },
     "localname": "FairValueInputsLevel2Member",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueInvestmentsEntitiesThatCalculateNetAssetValuePerShareTable": {
     "auth_ref": [
      "r380"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about investments in certain entities that calculate net asset value per share or equivalent measured at fair value on a recurring or nonrecurring basis.",
        "label": "Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Table]",
        "terseLabel": "Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Table]"
       }
      }
     },
     "localname": "FairValueInvestmentsEntitiesThatCalculateNetAssetValuePerShareTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueMeasurementFrequencyDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Measurement frequency.",
        "label": "Measurement Frequency [Domain]",
        "terseLabel": "Measurement Frequency [Domain]"
       }
      }
     },
     "localname": "FairValueMeasurementFrequencyDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueMeasurementsFairValueHierarchyDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Categories used to prioritize the inputs to valuation techniques to measure fair value.",
        "label": "Fair Value Hierarchy and NAV [Domain]",
        "terseLabel": "Fair Value, Measurements, Fair Value Hierarchy [Domain]"
       }
      }
     },
     "localname": "FairValueMeasurementsFairValueHierarchyDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueMeasurementsRecurringMember": {
     "auth_ref": [
      "r378",
      "r381"
     ],
     "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, Recurring [Member]",
        "terseLabel": "Fair Value, Recurring [Member]"
       }
      }
     },
     "localname": "FairValueMeasurementsRecurringMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueOfFinancialInstrumentsPolicy": {
     "auth_ref": [
      "r118",
      "r382",
      "r383"
     ],
     "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]",
        "verboseLabel": "Fair Value Of Financial Instruments"
       }
      }
     },
     "localname": "FairValueOfFinancialInstrumentsPolicy",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "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": "Finite-Lived Intangible Asset, Useful Life"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetUsefulLife",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization": {
     "auth_ref": [
      "r198"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails": {
       "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",
        "negatedLabel": "Accumulated Amortization"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAccumulatedAmortization",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths": {
     "auth_ref": [
      "r200"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsEstimatedAmortizationExpenseForIntangibleAssetsDetails": {
       "order": 1.0,
       "parentTag": "ffiv_FiniteLivedIntangibleAssetsTotalAmortizationExpenseForNextFiveYears",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months",
        "verboseLabel": "2021"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsEstimatedAmortizationExpenseForIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive": {
     "auth_ref": [
      "r200"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsEstimatedAmortizationExpenseForIntangibleAssetsDetails": {
       "order": 5.0,
       "parentTag": "ffiv_FiniteLivedIntangibleAssetsTotalAmortizationExpenseForNextFiveYears",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Finite-Lived Intangible Assets, Amortization Expense, Year Five",
        "verboseLabel": "2025"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseYearFive",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsEstimatedAmortizationExpenseForIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour": {
     "auth_ref": [
      "r200"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsEstimatedAmortizationExpenseForIntangibleAssetsDetails": {
       "order": 4.0,
       "parentTag": "ffiv_FiniteLivedIntangibleAssetsTotalAmortizationExpenseForNextFiveYears",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Finite-Lived Intangible Assets, Amortization Expense, Year Four",
        "verboseLabel": "2024"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseYearFour",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsEstimatedAmortizationExpenseForIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree": {
     "auth_ref": [
      "r200"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsEstimatedAmortizationExpenseForIntangibleAssetsDetails": {
       "order": 3.0,
       "parentTag": "ffiv_FiniteLivedIntangibleAssetsTotalAmortizationExpenseForNextFiveYears",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Finite-Lived Intangible Assets, Amortization Expense, Year Three",
        "verboseLabel": "2023"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseYearThree",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsEstimatedAmortizationExpenseForIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo": {
     "auth_ref": [
      "r200"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsEstimatedAmortizationExpenseForIntangibleAssetsDetails": {
       "order": 2.0,
       "parentTag": "ffiv_FiniteLivedIntangibleAssetsTotalAmortizationExpenseForNextFiveYears",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Finite-Lived Intangible Assets, Amortization Expense, Year Two",
        "verboseLabel": "2022"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsEstimatedAmortizationExpenseForIntangibleAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis": {
     "auth_ref": [
      "r193",
      "r195",
      "r198",
      "r201",
      "r423"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by major type or class of finite-lived intangible assets.",
        "label": "Finite-Lived Intangible Assets by Major Class [Axis]",
        "terseLabel": "Finite-Lived Intangible Assets by Major Class [Axis]"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsByMajorClassAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails",
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails",
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsGross": {
     "auth_ref": [
      "r198",
      "r423"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails": {
       "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",
        "verboseLabel": "Gross Carrying Amount"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsGross",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails"
     ],
     "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]",
        "terseLabel": "Finite-Lived Intangible Assets [Line Items]"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain": {
     "auth_ref": [
      "r193",
      "r197"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The major class of finite-lived intangible asset (for example, patents, trademarks, copyrights, etc.) 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": "Finite-Lived Intangible Assets, Major Class Name [Domain]",
        "terseLabel": "Finite-Lived Intangible Assets, Major Class Name [Domain]"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsMajorClassNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails",
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails",
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsNet": {
     "auth_ref": [
      "r198"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.f5.com/role/BalanceSheetDetailsOtherAssetsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_OtherAssetsNoncurrent",
       "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",
        "terseLabel": "Intangible assets",
        "totalLabel": "Net Carrying Amount"
       }
      }
     },
     "localname": "FiniteLivedIntangibleAssetsNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails",
      "http://www.f5.com/role/BalanceSheetDetailsOtherAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ForeignCountryMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Designated tax departments of governments entitled to levy and collect income taxes from the entity outside the entity's country of domicile.",
        "label": "Foreign Tax Authority [Member]",
        "terseLabel": "Foreign [Member]"
       }
      }
     },
     "localname": "ForeignCountryMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock": {
     "auth_ref": [
      "r118",
      "r386",
      "r389"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for (1) transactions denominated in a currency other than the reporting enterprise's functional currency, (2) translating foreign currency financial statements that are incorporated into the financial statements of the reporting enterprise by consolidation, combination, or the equity method of accounting, and (3) remeasurement of the financial statements of a foreign reporting enterprise in a hyperinflationary economy.",
        "label": "Foreign Currency Transactions and Translations Policy [Policy Text Block]",
        "verboseLabel": "Foreign Currency"
       }
      }
     },
     "localname": "ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FurnitureAndFixturesGross": {
     "auth_ref": [
      "r206"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsPropertyandEquipmentDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_PropertyPlantAndEquipmentGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before accumulated depreciation of equipment commonly used in offices and stores that have no permanent connection to the structure of a building or utilities. Examples include, but are not limited to, desks, chairs, tables, and bookcases.",
        "label": "Furniture and Fixtures, Gross",
        "terseLabel": "Office furniture and equipment",
        "verboseLabel": "Furniture and Fixtures, Gross"
       }
      }
     },
     "localname": "FurnitureAndFixturesGross",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsPropertyandEquipmentDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GeneralAndAdministrativeExpense": {
     "auth_ref": [
      "r85"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedIncomeStatements": {
       "order": 3.0,
       "parentTag": "us-gaap_OperatingExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.",
        "label": "General and Administrative Expense",
        "terseLabel": "General and administrative"
       }
      }
     },
     "localname": "GeneralAndAdministrativeExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GeneralAndAdministrativeExpenseMember": {
     "auth_ref": [
      "r81"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Primary financial statement caption encompassing general and administrative expense.",
        "label": "General and Administrative Expense [Member]",
        "terseLabel": "General and Administrative Expense"
       }
      }
     },
     "localname": "GeneralAndAdministrativeExpenseMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_GeographicConcentrationRiskMember": {
     "auth_ref": [
      "r148"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Reflects the percentage that a specified dollar value on the balance sheet or income statement in the period from one or more specified geographic areas is to a corresponding consolidated, segment, or product line amount. Risk is the materially adverse effects of economic decline or antagonistic political actions resulting in loss of assets, sales volume, labor supply, or source of materials and supplies in a US state or a specified country, continent, or region such as EMEA (Europe, Middle East, Africa).",
        "label": "Geographic Concentration Risk [Member]",
        "terseLabel": "Geographic Concentration Risk [Member]"
       }
      }
     },
     "localname": "GeographicConcentrationRiskMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_Goodwill": {
     "auth_ref": [
      "r186",
      "r187"
     ],
     "calculation": {
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails": {
       "order": 7.0,
       "parentTag": "us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets",
       "weight": 1.0
      },
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 5.0,
       "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",
        "periodEndLabel": "Goodwill, Ending Balance",
        "periodStartLabel": "Goodwill, Beginning Balance",
        "terseLabel": "Goodwill"
       }
      }
     },
     "localname": "Goodwill",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsGoodwillDetails",
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails",
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GoodwillAcquiredDuringPeriod": {
     "auth_ref": [
      "r188"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.",
        "label": "Goodwill, Acquired During Period",
        "terseLabel": "Goodwill, Acquired During Period"
       }
      }
     },
     "localname": "GoodwillAcquiredDuringPeriod",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsGoodwillDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy": {
     "auth_ref": [
      "r118",
      "r190"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for goodwill. This accounting policy also may address how an entity assesses and measures impairment of goodwill, how reporting units are determined, how goodwill is allocated to such units, and how the fair values of the reporting units are determined.",
        "label": "Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]",
        "terseLabel": "Goodwill"
       }
      }
     },
     "localname": "GoodwillAndIntangibleAssetsGoodwillPolicy",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_GoodwillAndIntangibleAssetsIntangibleAssetsPolicy": {
     "auth_ref": [
      "r118",
      "r196"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for intangible assets. This accounting policy may address both intangible assets subject to amortization and those that are not. The following also may be disclosed: (1) a description of intangible assets (2) the estimated useful lives of those assets (3) the amortization method used (4) how the entity assesses and measures impairment of such assets (5) how future cash flows are estimated (6) how the fair values of such asset are determined.",
        "label": "Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block]",
        "verboseLabel": "Intangible Assets"
       }
      }
     },
     "localname": "GoodwillAndIntangibleAssetsIntangibleAssetsPolicy",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_GoodwillOtherIncreaseDecrease": {
     "auth_ref": [
      "r189"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase (decrease), classified as other, of an asset representing the future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.",
        "label": "Goodwill, Other Increase (Decrease)",
        "negatedTerseLabel": "Goodwill, Other Increase (Decrease)"
       }
      }
     },
     "localname": "GoodwillOtherIncreaseDecrease",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsGoodwillDetails",
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GrossProfit": {
     "auth_ref": [
      "r83"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedIncomeStatements": {
       "order": 1.0,
       "parentTag": "us-gaap_OperatingIncomeLoss",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.",
        "label": "Gross Profit",
        "totalLabel": "Gross profit"
       }
      }
     },
     "localname": "GrossProfit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_GuaranteesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Guarantees [Abstract]",
        "terseLabel": "Guarantees and Product Warranties"
       }
      }
     },
     "localname": "GuaranteesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_GuaranteesIndemnificationsAndWarrantiesPolicies": {
     "auth_ref": [
      "r118",
      "r224"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for guarantees, indemnifications and product warranties, and methodologies used in determining the amount of such liabilities.",
        "label": "Guarantees, Indemnifications and Warranties Policies [Policy Text Block]",
        "verboseLabel": "Guarantees And Product Warranties"
       }
      }
     },
     "localname": "GuaranteesIndemnificationsAndWarrantiesPolicies",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock": {
     "auth_ref": [
      "r118",
      "r204",
      "r210"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for recognizing and measuring the impairment of long-lived assets. An entity also may disclose its accounting policy for long-lived assets to be sold. This policy excludes goodwill and intangible assets.",
        "label": "Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]",
        "verboseLabel": "Impairment Of Long-Lived Assets"
       }
      }
     },
     "localname": "ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic": {
     "auth_ref": [
      "r125"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesComponentsOfIncomeBeforeIncomeTaxesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations.",
        "label": "Income (Loss) from Continuing Operations before Income Taxes, Domestic",
        "terseLabel": "United States"
       }
      }
     },
     "localname": "IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesComponentsOfIncomeBeforeIncomeTaxesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign": {
     "auth_ref": [
      "r125"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesComponentsOfIncomeBeforeIncomeTaxesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile.",
        "label": "Income (Loss) from Continuing Operations before Income Taxes, Foreign",
        "terseLabel": "International"
       }
      }
     },
     "localname": "IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesComponentsOfIncomeBeforeIncomeTaxesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments": {
     "auth_ref": [
      "r125"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedIncomeStatements": {
       "order": 1.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "weight": 1.0
      },
      "http://www.f5.com/role/IncomeTaxesComponentsOfIncomeBeforeIncomeTaxesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.",
        "label": "Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest",
        "totalLabel": "Income before income taxes"
       }
      }
     },
     "localname": "IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/IncomeTaxesComponentsOfIncomeBeforeIncomeTaxesDetails",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeStatementAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Income Statement [Abstract]",
        "terseLabel": "Income Statement [Abstract]"
       }
      }
     },
     "localname": "IncomeStatementAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeStatementLocationAxis": {
     "auth_ref": [
      "r209"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by location in the income statement.",
        "label": "Income Statement Location [Axis]",
        "terseLabel": "Income Statement Location [Axis]"
       }
      }
     },
     "localname": "IncomeStatementLocationAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeStatementLocationDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Location in the income statement.",
        "label": "Income Statement Location [Domain]",
        "terseLabel": "Income Statement Location [Domain]"
       }
      }
     },
     "localname": "IncomeStatementLocationDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_IncomeTaxAuthorityAxis": {
     "auth_ref": [
      "r318"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by tax jurisdiction.",
        "label": "Income Tax Authority [Axis]",
        "terseLabel": "Income Tax Authority [Axis]"
       }
      }
     },
     "localname": "IncomeTaxAuthorityAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeTaxAuthorityDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Agency, division or body classification that levies income taxes, examines tax returns for compliance, or grants exemptions from or makes other decisions pertaining to income taxes.",
        "label": "Income Tax Authority [Domain]",
        "terseLabel": "Income Tax Authority [Domain]"
       }
      }
     },
     "localname": "IncomeTaxAuthorityDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_IncomeTaxDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Income Tax Disclosure [Abstract]",
        "terseLabel": "Income Tax Disclosure [Abstract]"
       }
      }
     },
     "localname": "IncomeTaxDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeTaxDisclosureTextBlock": {
     "auth_ref": [
      "r345"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.",
        "label": "Income Tax Disclosure [Text Block]",
        "terseLabel": "Income Taxes"
       }
      }
     },
     "localname": "IncomeTaxDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxes"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_IncomeTaxExpenseBenefit": {
     "auth_ref": [
      "r123",
      "r157",
      "r343"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedIncomeStatements": {
       "order": 2.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "weight": -1.0
      },
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "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)",
        "totalLabel": "Income taxes (benefit)",
        "verboseLabel": "Provision for income taxes"
       }
      }
     },
     "localname": "IncomeTaxExpenseBenefit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails",
      "http://www.f5.com/role/IncomeTaxesScheduleOfProvisionForIncomeTaxesBenefitDetails",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxHolidayAggregateDollarAmount": {
     "auth_ref": [
      "r342"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of income taxes from which a reporting entity is exempt or for which it will receive a reduction in income taxes as a result of the income tax holiday granted by the taxing jurisdiction.",
        "label": "Income Tax Holiday, Aggregate Dollar Amount",
        "terseLabel": "Income Tax Holiday, Aggregate Dollar Amount"
       }
      }
     },
     "localname": "IncomeTaxHolidayAggregateDollarAmount",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxHolidayIncomeTaxBenefitsPerShare": {
     "auth_ref": [
      "r342"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Per share amount effect of the income tax benefit resulting from the income tax holidays granted by taxing jurisdictions.",
        "label": "Income Tax Holiday, Income Tax Benefits Per Share",
        "terseLabel": "Income Tax Holiday, Income Tax Benefits Per Share"
       }
      }
     },
     "localname": "IncomeTaxHolidayIncomeTaxBenefitsPerShare",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_IncomeTaxPolicyTextBlock": {
     "auth_ref": [
      "r77",
      "r118",
      "r311",
      "r312",
      "r325",
      "r326",
      "r332",
      "r344",
      "r473"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.",
        "label": "Income Tax, Policy [Policy Text Block]",
        "verboseLabel": "Income Taxes"
       }
      }
     },
     "localname": "IncomeTaxPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_IncomeTaxReconciliationDeductionsQualifiedProductionActivities": {
     "auth_ref": [
      "r315",
      "r316"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails": {
       "order": 5.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of the difference between reported income tax expense (benefit) and the expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to deduction for qualified production activity.",
        "label": "Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Amount",
        "negatedLabel": "Domestic manufacturing deduction"
       }
      }
     },
     "localname": "IncomeTaxReconciliationDeductionsQualifiedProductionActivities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential": {
     "auth_ref": [
      "r121",
      "r315",
      "r316"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to foreign income tax expense (benefit).",
        "label": "Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount",
        "verboseLabel": "Tax impact of foreign operations"
       }
      }
     },
     "localname": "IncomeTaxReconciliationForeignIncomeTaxRateDifferential",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate": {
     "auth_ref": [
      "r122",
      "r315",
      "r316"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.",
        "label": "Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount",
        "verboseLabel": "Income tax provision at statutory rate"
       }
      }
     },
     "localname": "IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost": {
     "auth_ref": [
      "r315",
      "r316"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails": {
       "order": 6.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of reported income tax expense (benefit) in excess of (less than) expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to nondeductible expense for award under share-based payment arrangement. Includes, but is not limited to, expense determined to be nondeductible upon grant or after for award under share-based payment arrangement.",
        "label": "Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Payment Arrangement, Amount",
        "terseLabel": "Stock-based and other compensation"
       }
      }
     },
     "localname": "IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationOtherReconcilingItems": {
     "auth_ref": [
      "r315",
      "r316"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails": {
       "order": 8.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax exempt income, equity in earnings (loss) of an unconsolidated subsidiary, minority noncontrolling interest income (loss), tax holiday, disposition of a business, disposition of an asset, repatriation of foreign earnings, repatriation of foreign earnings jobs creation act of 2004, increase (decrease) in enacted tax rate, prior year income taxes, increase (decrease) in deferred tax asset valuation allowance, and other adjustments.",
        "label": "Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount",
        "verboseLabel": "Other"
       }
      }
     },
     "localname": "IncomeTaxReconciliationOtherReconcilingItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes": {
     "auth_ref": [
      "r122",
      "r315",
      "r316"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to state and local income tax expense (benefit).",
        "label": "Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount",
        "verboseLabel": "State taxes, net of federal benefit"
       }
      }
     },
     "localname": "IncomeTaxReconciliationStateAndLocalIncomeTaxes",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxReconciliationTaxCreditsResearch": {
     "auth_ref": [
      "r315",
      "r316"
     ],
     "calculation": {
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_IncomeTaxExpenseBenefit",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to research tax credit.",
        "label": "Effective Income Tax Rate Reconciliation, Tax Credit, Research, Amount",
        "negatedLabel": "Research and development and other credits"
       }
      }
     },
     "localname": "IncomeTaxReconciliationTaxCreditsResearch",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfEffectiveTaxRateDiffersFromTheUSFederalStatutoryRateDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncomeTaxesPaidNet": {
     "auth_ref": [
      "r112"
     ],
     "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, net of any cash received during the current period as refunds for the overpayment of taxes.",
        "label": "Income Taxes Paid, Net",
        "terseLabel": "Cash paid for taxes, net of refunds"
       }
      }
     },
     "localname": "IncomeTaxesPaidNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities": {
     "auth_ref": [
      "r107"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 13.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in the amounts payable to vendors for goods and services received and the amount of obligations and expenses incurred but not paid.",
        "label": "Increase (Decrease) in Accounts Payable and Accrued Liabilities",
        "terseLabel": "Accounts payable and accrued liabilities"
       }
      }
     },
     "localname": "IncreaseDecreaseInAccountsPayableAndAccruedLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInAccountsReceivable": {
     "auth_ref": [
      "r107"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 9.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in amount due within one year (or one business cycle) from customers for the credit sale of goods and services.",
        "label": "Increase (Decrease) in Accounts Receivable",
        "negatedLabel": "Accounts receivable"
       }
      }
     },
     "localname": "IncreaseDecreaseInAccountsReceivable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInDeferredRevenue": {
     "auth_ref": [
      "r107"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 14.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase (decrease) in deferred income and obligation to transfer product and service to customer for which consideration has been received or is receivable.",
        "label": "Increase (Decrease) in Deferred Revenue",
        "terseLabel": "Deferred revenue"
       }
      }
     },
     "localname": "IncreaseDecreaseInDeferredRevenue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInInventories": {
     "auth_ref": [
      "r107"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 10.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in the aggregate value of all inventory held by the reporting entity, associated with underlying transactions that are classified as operating activities.",
        "label": "Increase (Decrease) in Inventories",
        "negatedLabel": "Inventories"
       }
      }
     },
     "localname": "IncreaseDecreaseInInventories",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInOperatingCapitalAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Increase (Decrease) in Operating Capital [Abstract]",
        "terseLabel": "Changes in operating assets and liabilities (excluding effects of the acquisition of businesses):"
       }
      }
     },
     "localname": "IncreaseDecreaseInOperatingCapitalAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncreaseDecreaseInOtherCurrentAssets": {
     "auth_ref": [
      "r107"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 11.0,
       "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 current assets"
       }
      }
     },
     "localname": "IncreaseDecreaseInOtherCurrentAssets",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInOtherNoncurrentAssets": {
     "auth_ref": [
      "r107"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 12.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase (decrease) in noncurrent assets classified as other.",
        "label": "Increase (Decrease) in Other Noncurrent Assets",
        "negatedLabel": "Other assets"
       }
      }
     },
     "localname": "IncreaseDecreaseInOtherNoncurrentAssets",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IntellectualPropertyMember": {
     "auth_ref": [
      "r357"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Intangible asset arising from original creative thought. Include, but is not limited to, trademarks, patents, and copyrights.",
        "label": "Intellectual Property [Member]",
        "terseLabel": "Patents And Trademarks [Member]"
       }
      }
     },
     "localname": "IntellectualPropertyMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_InterestPaidNet": {
     "auth_ref": [
      "r102",
      "r105",
      "r112"
     ],
     "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, Excluding Capitalized Interest, Operating Activities",
        "terseLabel": "Cash paid for interest on long-term debt"
       }
      }
     },
     "localname": "InterestPaidNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InternalUseSoftwarePolicy": {
     "auth_ref": [
      "r118",
      "r202",
      "r203"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for costs incurred when both (1) the software is acquired, internally developed, or modified solely to meet the entity's internal needs, and (2) during the software's development or modification, no substantive plan exists or is being developed to market the software externally.",
        "label": "Internal Use Software, Policy [Policy Text Block]",
        "terseLabel": "Internal-Use Software"
       }
      }
     },
     "localname": "InternalUseSoftwarePolicy",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_InventoryFinishedGoods": {
     "auth_ref": [
      "r54"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsInventoriesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_InventoryNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer.",
        "label": "Inventory, Finished Goods, Gross",
        "terseLabel": "Finished goods",
        "verboseLabel": "Finished goods"
       }
      }
     },
     "localname": "InventoryFinishedGoods",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsInventoriesDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfInventoriesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InventoryNet": {
     "auth_ref": [
      "r2",
      "r56",
      "r178"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsInventoriesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.",
        "label": "Inventory, Net",
        "terseLabel": "Inventories",
        "totalLabel": "Inventory, Net",
        "verboseLabel": "Inventories, Total"
       }
      }
     },
     "localname": "InventoryNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsInventoriesDetails",
      "http://www.f5.com/role/ConsolidatedBalanceSheets",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfInventoriesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InventoryPolicyTextBlock": {
     "auth_ref": [
      "r12",
      "r57",
      "r118",
      "r140",
      "r179",
      "r180"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of inventory accounting policy for inventory classes, including, but not limited to, basis for determining inventory amounts, methods by which amounts are added and removed from inventory classes, loss recognition on impairment of inventories, and situations in which inventories are stated above cost.",
        "label": "Inventory, Policy [Policy Text Block]",
        "verboseLabel": "Inventories"
       }
      }
     },
     "localname": "InventoryPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_InventoryRawMaterials": {
     "auth_ref": [
      "r55"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsInventoriesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_InventoryNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before valuation and LIFO reserves of raw materials expected to be sold, or consumed within one year or operating cycle, if longer.",
        "label": "Inventory, Raw Materials, Gross",
        "terseLabel": "Raw materials",
        "verboseLabel": "Raw materials"
       }
      }
     },
     "localname": "InventoryRawMaterials",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsInventoriesDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfInventoriesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InvestmentIncomeInterest": {
     "auth_ref": [
      "r87",
      "r155"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.",
        "label": "Investment Income, Interest",
        "terseLabel": "Investment Income, Interest"
       }
      }
     },
     "localname": "InvestmentIncomeInterest",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InvestmentPolicyTextBlock": {
     "auth_ref": [
      "r176"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for investment in financial asset.",
        "label": "Investment, Policy [Policy Text Block]",
        "verboseLabel": "Investments"
       }
      }
     },
     "localname": "InvestmentPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_InvestmentTypeAxis": {
     "auth_ref": [
      "r467",
      "r468",
      "r469",
      "r470"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by type of investments.",
        "label": "Investment Type [Axis]",
        "terseLabel": "Investment Type [Axis]"
       }
      }
     },
     "localname": "InvestmentTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsTables"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_InvestmentTypeCategorizationMember": {
     "auth_ref": [
      "r467",
      "r468",
      "r469",
      "r470"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Asset obtained to generate income or appreciate in value.",
        "label": "Investments [Domain]",
        "terseLabel": "Investments [Domain]"
       }
      }
     },
     "localname": "InvestmentTypeCategorizationMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsTables"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_InvestmentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Investments [Abstract]",
        "terseLabel": "Investments [Abstract]"
       }
      }
     },
     "localname": "InvestmentsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Investments, Debt and Equity Securities [Abstract]"
       }
      }
     },
     "localname": "InvestmentsDebtAndEquitySecuritiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock": {
     "auth_ref": [
      "r175",
      "r424",
      "r440",
      "r471"
     ],
     "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]",
        "terseLabel": "Short-Term And Long-Term Investments"
       }
      }
     },
     "localname": "InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestments"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LeaseCost": {
     "auth_ref": [
      "r413",
      "r415"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseExpenseDetails": {
       "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 expense"
       }
      }
     },
     "localname": "LeaseCost",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LeaseCostTableTextBlock": {
     "auth_ref": [
      "r413"
     ],
     "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": "Lease, Cost"
       }
      }
     },
     "localname": "LeaseCostTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LeaseholdImprovementsGross": {
     "auth_ref": [
      "r8",
      "r206"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsPropertyandEquipmentDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_PropertyPlantAndEquipmentGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before accumulated depreciation of additions or improvements to assets held under a lease arrangement.",
        "label": "Leasehold Improvements, Gross",
        "terseLabel": "Leasehold improvements",
        "verboseLabel": "Leasehold Improvements, Gross"
       }
      }
     },
     "localname": "LeaseholdImprovementsGross",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsPropertyandEquipmentDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LeasesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Leases [Abstract]"
       }
      }
     },
     "localname": "LeasesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "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]",
        "terseLabel": "Lessee, Lease, Description [Line Items]"
       }
      }
     },
     "localname": "LesseeLeaseDescriptionLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LesseeLeaseDescriptionTable": {
     "auth_ref": [
      "r404"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about lessee's leases.",
        "label": "Lessee, Lease, Description [Table]",
        "terseLabel": "Lessee, Lease, Description [Table]"
       }
      }
     },
     "localname": "LesseeLeaseDescriptionTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock": {
     "auth_ref": [
      "r414"
     ],
     "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": "Lessee, Operating Lease, Liability, Maturity"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityMaturityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue": {
     "auth_ref": [
      "r414"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails_1": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payments for operating lease.",
        "label": "Lessee, Operating Lease, Liability, Payments, Due",
        "totalLabel": "Total lease payments"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive": {
     "auth_ref": [
      "r414"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails_1": {
       "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 payments for operating lease, due after fifth fiscal year following latest fiscal year.",
        "label": "Lessee, Operating Lease, Liability, Payments, Due after Year Five",
        "terseLabel": "Thereafter"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths": {
     "auth_ref": [
      "r414"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails_1": {
       "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 for operating lease, due in next fiscal year following latest fiscal year.",
        "label": "Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months",
        "terseLabel": "2021"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive": {
     "auth_ref": [
      "r414"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails_1": {
       "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 payments for operating lease, due in fifth fiscal year following latest fiscal year.",
        "label": "Lessee, Operating Lease, Liability, Payments, Due Year Five",
        "terseLabel": "2025"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearFive",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour": {
     "auth_ref": [
      "r414"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails_1": {
       "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 payments for operating lease, due in fourth fiscal year following latest fiscal year.",
        "label": "Lessee, Operating Lease, Liability, Payments, Due Year Four",
        "terseLabel": "2024"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearFour",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree": {
     "auth_ref": [
      "r414"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails_1": {
       "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 payments for operating lease, due in third fiscal year following latest fiscal year.",
        "label": "Lessee, Operating Lease, Liability, Payments, Due Year Three",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearThree",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo": {
     "auth_ref": [
      "r414"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails_1": {
       "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 in second fiscal year following latest fiscal year.",
        "label": "Lessee, Operating Lease, Liability, Payments, Due Year Two",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearTwo",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount": {
     "auth_ref": [
      "r414"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails": {
       "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",
        "negatedTerseLabel": "Less: imputed interest"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityUndiscountedExcessAmount",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeasesTextBlock": {
     "auth_ref": [
      "r416"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/Leases"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths": {
     "auth_ref": [
      "r417"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of lease payments to be received by lessor in next fiscal year following latest fiscal year for operating lease. Excludes interim and annual periods when interim periods are reported on rolling approach, from latest statement of financial position date.",
        "label": "Lessor, Operating Lease, Payments to be Received, Next Twelve Months",
        "terseLabel": "Lessor, Operating Lease, Payments to be Received, Next Twelve Months"
       }
      }
     },
     "localname": "LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesAndStockholdersEquity": {
     "auth_ref": [
      "r30",
      "r431",
      "r454"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "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 shareholders\u2019 equity"
       }
      }
     },
     "localname": "LiabilitiesAndStockholdersEquity",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesAndStockholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Liabilities and Equity [Abstract]",
        "terseLabel": "LIABILITIES AND SHAREHOLDERS\u2019 EQUITY"
       }
      }
     },
     "localname": "LiabilitiesAndStockholdersEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LiabilitiesCurrent": {
     "auth_ref": [
      "r46"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer.",
        "label": "Liabilities, Current",
        "totalLabel": "Total current liabilities"
       }
      }
     },
     "localname": "LiabilitiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesNoncurrent": {
     "auth_ref": [
      "r13",
      "r14",
      "r15",
      "r20",
      "r21"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of obligation due after one year or beyond the normal operating cycle, if longer.",
        "label": "Liabilities, Noncurrent",
        "totalLabel": "Total long-term liabilities"
       }
      }
     },
     "localname": "LiabilitiesNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LineOfCredit": {
     "auth_ref": [
      "r20",
      "r429",
      "r446"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.",
        "label": "Long-term Line of Credit",
        "terseLabel": "Long-term Line of Credit"
       }
      }
     },
     "localname": "LineOfCredit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LineOfCreditFacilityCommitmentFeePercentage": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.",
        "label": "Line of Credit Facility, Commitment Fee Percentage",
        "terseLabel": "Commitment Fee Percentage"
       }
      }
     },
     "localname": "LineOfCreditFacilityCommitmentFeePercentage",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd": {
     "auth_ref": [
      "r42"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The effective interest rate at the end of the reporting period.",
        "label": "Line of Credit Facility, Interest Rate at Period End",
        "terseLabel": "Interest Rate at Period End"
       }
      }
     },
     "localname": "LineOfCreditFacilityInterestRateAtPeriodEnd",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity": {
     "auth_ref": [
      "r42"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.",
        "label": "Line of Credit Facility, Maximum Borrowing Capacity",
        "terseLabel": "Aggregate Principal Amount"
       }
      }
     },
     "localname": "LineOfCreditFacilityMaximumBorrowingCapacity",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity": {
     "auth_ref": [
      "r42"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).",
        "label": "Line of Credit Facility, Remaining Borrowing Capacity",
        "terseLabel": "Outstanding Line of Credit Balance"
       }
      }
     },
     "localname": "LineOfCreditFacilityRemainingBorrowingCapacity",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LondonInterbankOfferedRateLIBORMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Interest rate at which a bank borrows funds from other banks in the London interbank market.",
        "label": "London Interbank Offered Rate (LIBOR) [Member]",
        "terseLabel": "London Interbank Offered Rate (LIBOR) [Member]"
       }
      }
     },
     "localname": "LondonInterbankOfferedRateLIBORMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LongLivedAssetsByGeographicAreasTableTextBlock": {
     "auth_ref": [
      "r163"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of long-lived assets, excluding financial instruments, long-term customer relationships of a financial institution, mortgage rights, deferred policy acquisition costs, and deferred tax assets, by geographic areas located in the entity's country of domicile and foreign countries in which the entity holds assets.",
        "label": "Long-lived Assets by Geographic Areas [Table Text Block]",
        "terseLabel": "Long-lived Assets by Geographic Areas [Table Text Block]"
       }
      }
     },
     "localname": "LongLivedAssetsByGeographicAreasTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LongTermDebt": {
     "auth_ref": [
      "r20",
      "r226",
      "r429",
      "r450"
     ],
     "calculation": {
      "http://www.f5.com/role/DebtFacilitiesLongtermDebtMaturitiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.",
        "label": "Long-term Debt",
        "terseLabel": "Long-term Debt",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "LongTermDebt",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesLongtermDebtMaturitiesDetails",
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtCurrent": {
     "auth_ref": [
      "r44"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.",
        "label": "Long-term Debt, Current Maturities",
        "terseLabel": "Current portion of long-term debt"
       }
      }
     },
     "localname": "LongTermDebtCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour": {
     "auth_ref": [
      "r127",
      "r225"
     ],
     "calculation": {
      "http://www.f5.com/role/DebtFacilitiesLongtermDebtMaturitiesDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_LongTermDebt",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Long-term Debt, Maturities, Repayments of Principal in Year Four",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesLongtermDebtMaturitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree": {
     "auth_ref": [
      "r127",
      "r225"
     ],
     "calculation": {
      "http://www.f5.com/role/DebtFacilitiesLongtermDebtMaturitiesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_LongTermDebt",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Long-term Debt, Maturities, Repayments of Principal in Year Three",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesLongtermDebtMaturitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo": {
     "auth_ref": [
      "r127",
      "r225"
     ],
     "calculation": {
      "http://www.f5.com/role/DebtFacilitiesLongtermDebtMaturitiesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_LongTermDebt",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Long-term Debt, Maturities, Repayments of Principal in Year Two",
        "terseLabel": "2021"
       }
      }
     },
     "localname": "LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesLongtermDebtMaturitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtNoncurrent": {
     "auth_ref": [
      "r47"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_LiabilitiesNoncurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.",
        "label": "Long-term Debt, Excluding Current Maturities",
        "terseLabel": "Long-term debt"
       }
      }
     },
     "localname": "LongTermDebtNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermInvestments": {
     "auth_ref": [
      "r36"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle).",
        "label": "Long-term Investments",
        "terseLabel": "Long-term investments"
       }
      }
     },
     "localname": "LongTermInvestments",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_MachineryAndEquipmentGross": {
     "auth_ref": [
      "r8",
      "r206"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsPropertyandEquipmentDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_PropertyPlantAndEquipmentGross",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before accumulated depreciation of tangible personal property used to produce goods and services, including, but is not limited to, tools, dies and molds, computer and office equipment.",
        "label": "Machinery and Equipment, Gross",
        "terseLabel": "Computer equipment",
        "verboseLabel": "Machinery and Equipment, Gross"
       }
      }
     },
     "localname": "MachineryAndEquipmentGross",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsPropertyandEquipmentDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_MaintenanceMember": {
     "auth_ref": [
      "r252"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Process of preserving asset, including, but not limited to, building, machinery and software.",
        "label": "Maintenance [Member]",
        "terseLabel": "Maintenance [Member]"
       }
      }
     },
     "localname": "MaintenanceMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_MarketingAndAdvertisingExpenseAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Marketing and Advertising Expense [Abstract]",
        "terseLabel": "Advertising"
       }
      }
     },
     "localname": "MarketingAndAdvertisingExpenseAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetCashProvidedByUsedInFinancingActivities": {
     "auth_ref": [
      "r104"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "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 provided by (used in) financing activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInFinancingActivities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Net Cash Provided by (Used in) Financing Activities [Abstract]",
        "terseLabel": "Financing activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInFinancingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetCashProvidedByUsedInInvestingActivities": {
     "auth_ref": [
      "r104"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "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 in investing activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInInvestingActivities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Net Cash Provided by (Used in) Investing Activities [Abstract]",
        "terseLabel": "Investing activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInInvestingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetCashProvidedByUsedInOperatingActivities": {
     "auth_ref": [
      "r104",
      "r106",
      "r109"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "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 provided by operating activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInOperatingActivities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Net Cash Provided by (Used in) Operating Activities [Abstract]",
        "terseLabel": "Operating activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInOperatingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetIncomeLoss": {
     "auth_ref": [
      "r72",
      "r75",
      "r79",
      "r109",
      "r137",
      "r438",
      "r457"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedIncomeStatements": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      },
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement": {
       "order": 1.0,
       "parentTag": "us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest",
       "weight": 1.0
      }
     },
     "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"
       }
      }
     },
     "localname": "NetIncomeLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity",
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows",
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement",
      "http://www.f5.com/role/NetIncomePerShareDetails",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfComputationOfBasicAndDilutedNetIncomePerShareDetails"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_NoncompeteAgreementsMember": {
     "auth_ref": [
      "r354"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Agreement in which one party agrees not to pursue a similar trade in competition with another party.",
        "label": "Noncompete Agreements [Member]",
        "terseLabel": "Non-Compete Covenants [Member]"
       }
      }
     },
     "localname": "NoncompeteAgreementsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_NumberOfReportableSegments": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.",
        "label": "Number of Reportable Segments",
        "terseLabel": "Number of Reportable Segments"
       }
      }
     },
     "localname": "NumberOfReportableSegments",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "us-gaap_OperatingExpenses": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedIncomeStatements": {
       "order": 2.0,
       "parentTag": "us-gaap_OperatingIncomeLoss",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense.",
        "label": "Operating Expenses",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "OperatingExpenses",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingExpensesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Operating Expenses [Abstract]",
        "terseLabel": "Operating expenses"
       }
      }
     },
     "localname": "OperatingExpensesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OperatingIncomeLoss": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedIncomeStatements": {
       "order": 1.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The net result for the period of deducting operating expenses from operating revenues.",
        "label": "Operating Income (Loss)",
        "totalLabel": "Income from operations"
       }
      }
     },
     "localname": "OperatingIncomeLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseCost": {
     "auth_ref": [
      "r405",
      "r415"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseExpenseDetails": {
       "order": 1.0,
       "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 expense"
       }
      }
     },
     "localname": "OperatingLeaseCost",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseImpairmentLoss": {
     "auth_ref": [
      "r400"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of loss from impairment of right-of-use asset from operating lease.",
        "label": "Operating Lease, Impairment Loss",
        "terseLabel": "Operating Lease, Impairment Loss"
       }
      }
     },
     "localname": "OperatingLeaseImpairmentLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsImpairmentofAssetsMeasuredatFairValueonaNonrecurringBasisDetails",
      "http://www.f5.com/role/LeasesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseLiability": {
     "auth_ref": [
      "r402"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      },
      "http://www.f5.com/role/LeasesSupplementalBalanceSheetDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Present value of lessee's discounted obligation for lease payments from operating lease.",
        "label": "Operating Lease, Liability",
        "terseLabel": "Total lease liabilities",
        "totalLabel": "Total lease liabilities"
       }
      }
     },
     "localname": "OperatingLeaseLiability",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesMaturitiesofLeaseLiabilitiesDetails",
      "http://www.f5.com/role/LeasesSupplementalBalanceSheetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseLiabilityCurrent": {
     "auth_ref": [
      "r402"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsAccruedLiabilitiesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_AccruedLiabilitiesCurrent",
       "weight": 1.0
      },
      "http://www.f5.com/role/LeasesSupplementalBalanceSheetDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_OperatingLeaseLiability",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Present value of lessee's discounted obligation for lease payments from operating lease, classified as current.",
        "label": "Operating Lease, Liability, Current",
        "terseLabel": "Operating lease liabilities, current"
       }
      }
     },
     "localname": "OperatingLeaseLiabilityCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsAccruedLiabilitiesDetails",
      "http://www.f5.com/role/LeasesSupplementalBalanceSheetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseLiabilityNoncurrent": {
     "auth_ref": [
      "r402"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_LiabilitiesNoncurrent",
       "weight": 1.0
      },
      "http://www.f5.com/role/LeasesSupplementalBalanceSheetDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_OperatingLeaseLiability",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent.",
        "label": "Operating Lease, Liability, Noncurrent",
        "terseLabel": "Operating lease liabilities, long-term"
       }
      }
     },
     "localname": "OperatingLeaseLiabilityNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets",
      "http://www.f5.com/role/LeasesSupplementalBalanceSheetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasePayments": {
     "auth_ref": [
      "r403",
      "r409"
     ],
     "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": "Cash paid for amounts included in the measurement of operating lease liabilities"
       }
      }
     },
     "localname": "OperatingLeasePayments",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseRightOfUseAsset": {
     "auth_ref": [
      "r401"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 2.0,
       "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",
        "terseLabel": "Operating lease right-of-use assets"
       }
      }
     },
     "localname": "OperatingLeaseRightOfUseAsset",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets",
      "http://www.f5.com/role/LeasesNarrativeDetails",
      "http://www.f5.com/role/LeasesSupplementalBalanceSheetDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent": {
     "auth_ref": [
      "r412",
      "r415"
     ],
     "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"
       }
      }
     },
     "localname": "OperatingLeaseWeightedAverageDiscountRatePercent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesSupplementalBalanceSheetDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1": {
     "auth_ref": [
      "r411",
      "r415"
     ],
     "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 (in years)"
       }
      }
     },
     "localname": "OperatingLeaseWeightedAverageRemainingLeaseTerm1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesSupplementalBalanceSheetDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsDue": {
     "auth_ref": [
      "r394",
      "r396"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": 1.0,
       "parentTag": "ffiv_FutureMinimumOperatingNetLeasePayments",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.",
        "label": "Operating Leases, Future Minimum Payments Due",
        "totalLabel": "Gross Lease Payments, Total"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsDue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]",
        "terseLabel": "Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsDueAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent": {
     "auth_ref": [
      "r394",
      "r396"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": 1.0,
       "parentTag": "us-gaap_OperatingLeasesFutureMinimumPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Operating Leases, Future Minimum Payments Due, Next Twelve Months",
        "terseLabel": "2020"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsDueCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears": {
     "auth_ref": [
      "r394",
      "r396"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": 5.0,
       "parentTag": "us-gaap_OperatingLeasesFutureMinimumPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Operating Leases, Future Minimum Payments, Due in Five Years",
        "terseLabel": "2024"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsDueInFiveYears",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears": {
     "auth_ref": [
      "r394",
      "r396"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": 4.0,
       "parentTag": "us-gaap_OperatingLeasesFutureMinimumPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Operating Leases, Future Minimum Payments, Due in Four Years",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsDueInFourYears",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears": {
     "auth_ref": [
      "r394",
      "r396"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": 3.0,
       "parentTag": "us-gaap_OperatingLeasesFutureMinimumPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Operating Leases, Future Minimum Payments, Due in Three Years",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsDueInThreeYears",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears": {
     "auth_ref": [
      "r394",
      "r396"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": 2.0,
       "parentTag": "us-gaap_OperatingLeasesFutureMinimumPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Operating Leases, Future Minimum Payments, Due in Two Years",
        "terseLabel": "2021"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsDueInTwoYears",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter": {
     "auth_ref": [
      "r394",
      "r396"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": 6.0,
       "parentTag": "us-gaap_OperatingLeasesFutureMinimumPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.",
        "label": "Operating Leases, Future Minimum Payments, Due Thereafter",
        "terseLabel": "Thereafter"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsDueThereafter",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsReceivable": {
     "auth_ref": [
      "r398"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": 2.0,
       "parentTag": "ffiv_FutureMinimumOperatingNetLeasePayments",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Future minimum rental payments in aggregate as of the balance sheet date under operating leases.",
        "label": "Operating Leases, Future Minimum Payments Receivable",
        "totalLabel": "Operating Leases, Future Minimum Payments Receivable"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsReceivable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Operating Leases, Future Minimum Payments Receivable [Abstract]",
        "terseLabel": "Operating Leases, Future Minimum Payments Receivable [Abstract]"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsReceivableAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableCurrent": {
     "auth_ref": [
      "r398"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": 2.0,
       "parentTag": "ffiv_FutureMinimumOperatingNetLeasePaymentsWithinOneYear",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Future rental payments receivable within one year of the balance sheet date under an operating lease.",
        "label": "Operating Leases, Future Minimum Payments Receivable, Current",
        "terseLabel": "2020"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsReceivableCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFiveYears": {
     "auth_ref": [
      "r398"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": 5.0,
       "parentTag": "us-gaap_OperatingLeasesFutureMinimumPaymentsReceivable",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Future rental payments receivable within the fifth year from the balance sheet date under an operating lease.",
        "label": "Operating Leases, Future Minimum Payments Receivable, in Five Years",
        "terseLabel": "2024"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsReceivableInFiveYears",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFourYears": {
     "auth_ref": [
      "r398"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": 4.0,
       "parentTag": "us-gaap_OperatingLeasesFutureMinimumPaymentsReceivable",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Future rental payments receivable within the fourth year from the balance sheet date under an operating lease.",
        "label": "Operating Leases, Future Minimum Payments Receivable, in Four Years",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsReceivableInFourYears",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInThreeYears": {
     "auth_ref": [
      "r398"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": 3.0,
       "parentTag": "us-gaap_OperatingLeasesFutureMinimumPaymentsReceivable",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Future rental payments receivable within the third year from the balance sheet date under an operating lease.",
        "label": "Operating Leases, Future Minimum Payments Receivable, in Three Years",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsReceivableInThreeYears",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInTwoYears": {
     "auth_ref": [
      "r398"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": 2.0,
       "parentTag": "us-gaap_OperatingLeasesFutureMinimumPaymentsReceivable",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Future rental payments receivable within the second year from the balance sheet date under an operating lease.",
        "label": "Operating Leases, Future Minimum Payments Receivable, in Two Years",
        "terseLabel": "2021"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsReceivableInTwoYears",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableThereafter": {
     "auth_ref": [
      "r398"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details": {
       "order": 6.0,
       "parentTag": "us-gaap_OperatingLeasesFutureMinimumPaymentsReceivable",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Future minimum lease payments receivable under operating leases for periods greater than five years following the balance sheet date.",
        "label": "Operating Leases, Future Minimum Payments Receivable, Thereafter",
        "terseLabel": "Thereafter"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsReceivableThereafter",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseFutureMinimumASC840Details"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLossCarryforwardsLineItems": {
     "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": "Operating Loss Carryforwards [Line Items]",
        "terseLabel": "Operating Loss Carryforwards [Line Items]"
       }
      }
     },
     "localname": "OperatingLossCarryforwardsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OperatingLossCarryforwardsTable": {
     "auth_ref": [
      "r334"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule reflecting pertinent information, such as tax authority, amounts, and expiration dates, of net operating loss carryforwards, including an assessment of the likelihood of utilization.",
        "label": "Operating Loss Carryforwards [Table]",
        "terseLabel": "Operating Loss Carryforwards [Table]"
       }
      }
     },
     "localname": "OperatingLossCarryforwardsTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OtherAccruedLiabilitiesCurrent": {
     "auth_ref": [
      "r9",
      "r10",
      "r11",
      "r45"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsAccruedLiabilitiesDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_AccruedLiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of expenses incurred but not yet paid classified as other, due within one year or the normal operating cycle, if longer.",
        "label": "Other Accrued Liabilities, Current",
        "verboseLabel": "Other"
       }
      }
     },
     "localname": "OtherAccruedLiabilitiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsAccruedLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherAccruedLiabilitiesNoncurrent": {
     "auth_ref": [
      "r48"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsOtherLongtermLiabilitiesDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_OtherLiabilitiesNoncurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of expenses incurred but not yet paid classified as other, due after one year or the normal operating cycle, if longer.",
        "label": "Other Accrued Liabilities, Noncurrent",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "OtherAccruedLiabilitiesNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsOtherLongtermLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherAssetsCurrent": {
     "auth_ref": [
      "r58"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsOtherCurrentAssetsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 5.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of current assets classified as other.",
        "label": "Other Assets, Current",
        "terseLabel": "Other current assets",
        "totalLabel": "Other Assets, Current"
       }
      }
     },
     "localname": "OtherAssetsCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsOtherCurrentAssetsDetails",
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherAssetsMiscellaneousCurrent": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsOtherCurrentAssetsDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_OtherAssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of other miscellaneous assets expected to be realized or consumed within one year or operating cycle, if longer.",
        "label": "Other Assets, Miscellaneous, Current",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "OtherAssetsMiscellaneousCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsOtherCurrentAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherAssetsMiscellaneousNoncurrent": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsOtherAssetsDetails": {
       "order": 4.0,
       "parentTag": "us-gaap_OtherAssetsNoncurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of other miscellaneous assets expected to be realized or consumed after one year or normal operating cycle, if longer.",
        "label": "Other Assets, Miscellaneous, Noncurrent",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "OtherAssetsMiscellaneousNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsOtherAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherAssetsNoncurrent": {
     "auth_ref": [
      "r40"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsOtherAssetsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 6.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of noncurrent assets classified as other.",
        "label": "Other Assets, Noncurrent",
        "terseLabel": "Other assets, net",
        "totalLabel": "Other Assets, Noncurrent"
       }
      }
     },
     "localname": "OtherAssetsNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsOtherAssetsDetails",
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeAvailableForSaleSecuritiesAdjustmentNetOfTaxPeriodIncreaseDecreaseAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax [Abstract]",
        "terseLabel": "Available-for-sale securities:"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeAvailableForSaleSecuritiesAdjustmentNetOfTaxPeriodIncreaseDecreaseAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent": {
     "auth_ref": [
      "r363",
      "r364",
      "r366"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement": {
       "order": 1.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after tax and reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities, attributable to parent entity. Excludes amounts related to other than temporary impairment (OTTI) loss.",
        "label": "Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent",
        "totalLabel": "Net change in unrealized gains (losses) on available-for-sale securities, net of tax"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax": {
     "auth_ref": [
      "r61",
      "r388"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement": {
       "order": 2.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeLossNetOfTax",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.",
        "label": "Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax",
        "verboseLabel": "Foreign currency translation adjustment"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossNetOfTax": {
     "auth_ref": [
      "r73",
      "r76",
      "r78",
      "r228"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement": {
       "order": 2.0,
       "parentTag": "us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest",
       "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",
        "totalLabel": "Total other comprehensive income (loss)",
        "verboseLabel": "Other comprehensive income (loss)"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity",
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Other Comprehensive Income (Loss), Net of Tax [Abstract]",
        "terseLabel": "Other Comprehensive Income (Loss), Net of Tax [Abstract]"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax": {
     "auth_ref": [
      "r65",
      "r69",
      "r70",
      "r174"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement": {
       "order": 2.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.",
        "label": "Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax",
        "negatedTerseLabel": "Reclassification adjustment for realized losses included in net income, net of taxes of $(65), $(35), and $(4) for the years ended September 30, 2020, 2019, and 2018, respectively"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax": {
     "auth_ref": [
      "r66",
      "r174"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.",
        "label": "Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax",
        "terseLabel": "Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeParentheticals"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax": {
     "auth_ref": [
      "r62",
      "r65"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement": {
       "order": 1.0,
       "parentTag": "us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after tax, before reclassification adjustments, of unrealized holding gain (loss) on available-for-sale securities.",
        "label": "Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax",
        "terseLabel": "Unrealized gains (losses) on securities, net of taxes of $76, $954, and $(869) for the years ended September 30, 2020, 2019, and 2018, respectively"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeStatement"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax": {
     "auth_ref": [
      "r63",
      "r66"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of tax expense (benefit) before reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities.",
        "label": "Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax",
        "terseLabel": "Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsofComprehensiveIncomeParentheticals"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherLiabilitiesNoncurrent": {
     "auth_ref": [
      "r48"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsOtherLongtermLiabilitiesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 5.0,
       "parentTag": "us-gaap_LiabilitiesNoncurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer.",
        "label": "Other Liabilities, Noncurrent",
        "terseLabel": "Other long-term liabilities",
        "totalLabel": "Other Liabilities, Noncurrent"
       }
      }
     },
     "localname": "OtherLiabilitiesNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsOtherLongtermLiabilitiesDetails",
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherNoncashIncomeExpense": {
     "auth_ref": [
      "r109"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of income (expense) included in net income that results in no cash inflow (outflow), classified as other.",
        "label": "Other Noncash Income (Expense)",
        "negatedTerseLabel": "Other"
       }
      }
     },
     "localname": "OtherNoncashIncomeExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherNoncurrentLiabilitiesTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of other noncurrent liabilities.",
        "label": "Other Noncurrent Liabilities [Table Text Block]",
        "terseLabel": "Other Long-term Liabilities"
       }
      }
     },
     "localname": "OtherNoncurrentLiabilitiesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_OtherNonoperatingIncomeExpense": {
     "auth_ref": [
      "r89"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedIncomeStatements": {
       "order": 2.0,
       "parentTag": "us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of income (expense) related to nonoperating activities, classified as other.",
        "label": "Other Nonoperating Income (Expense)",
        "terseLabel": "Other income, net"
       }
      }
     },
     "localname": "OtherNonoperatingIncomeExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherSignificantNoncashTransactionValueOfConsiderationReceived1": {
     "auth_ref": [
      "r113",
      "r114",
      "r115"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The value of the noncash (or part noncash) consideration received in a transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. \"Part noncash\" refers to that portion of a transaction not resulting in cash receipts or cash payments in the period.",
        "label": "Other Significant Noncash Transaction, Value of Consideration Received",
        "terseLabel": "Capitalized leasehold improvements paid directly by landlord"
       }
      }
     },
     "localname": "OtherSignificantNoncashTransactionValueOfConsiderationReceived1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsForRepurchaseOfCommonStock": {
     "auth_ref": [
      "r99"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "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",
        "negatedLabel": "Repurchase of common stock"
       }
      }
     },
     "localname": "PaymentsForRepurchaseOfCommonStock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsForRestructuring": {
     "auth_ref": [
      "r103",
      "r212"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.",
        "label": "Payments for Restructuring",
        "negatedTerseLabel": "Cash payments"
       }
      }
     },
     "localname": "PaymentsForRestructuring",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RestructuringChargesRestructuringActivityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsOfDebtIssuanceCosts": {
     "auth_ref": [
      "r101"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt.",
        "label": "Payments of Debt Issuance Costs",
        "negatedTerseLabel": "Payments for debt issuance costs"
       }
      }
     },
     "localname": "PaymentsOfDebtIssuanceCosts",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquireBusinessesGross": {
     "auth_ref": [
      "r94",
      "r358"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.",
        "label": "Payments to Acquire Businesses, Gross",
        "terseLabel": "Total Purchase Price"
       }
      }
     },
     "localname": "PaymentsToAcquireBusinessesGross",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired": {
     "auth_ref": [
      "r94"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.",
        "label": "Payments to Acquire Businesses, Net of Cash Acquired",
        "negatedTerseLabel": "Acquisition of businesses, net of cash acquired"
       }
      }
     },
     "localname": "PaymentsToAcquireBusinessesNetOfCashAcquired",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquireInvestments": {
     "auth_ref": [
      "r96"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash outflow associated with the purchase of all investments (debt, security, other) during the period.",
        "label": "Payments to Acquire Investments",
        "negatedLabel": "Purchases of investments"
       }
      }
     },
     "localname": "PaymentsToAcquireInvestments",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquirePropertyPlantAndEquipment": {
     "auth_ref": [
      "r95"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 6.0,
       "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",
        "negatedLabel": "Purchases of property and equipment"
       }
      }
     },
     "localname": "PaymentsToAcquirePropertyPlantAndEquipment",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PerformanceSharesMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Share-based payment arrangement awarded for meeting performance target.",
        "label": "Performance Shares [Member]",
        "terseLabel": "Performance Shares [Member]"
       }
      }
     },
     "localname": "PerformanceSharesMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PlanNameAxis": {
     "auth_ref": [
      "r266",
      "r298"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by plan name for share-based payment arrangement.",
        "label": "Plan Name [Axis]",
        "terseLabel": "Plan Name [Axis]"
       }
      }
     },
     "localname": "PlanNameAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PlanNameDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Plan name for share-based payment arrangement.",
        "label": "Plan Name [Domain]",
        "terseLabel": "Plan Name [Domain]"
       }
      }
     },
     "localname": "PlanNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PreferredStockNoParValue": {
     "auth_ref": [
      "r26"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Face amount per share of no-par value preferred stock nonredeemable or redeemable solely at the option of the issuer.",
        "label": "Preferred Stock, No Par Value",
        "terseLabel": "Preferred stock, par value (USD per share)"
       }
      }
     },
     "localname": "PreferredStockNoParValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets",
      "http://www.f5.com/role/ConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_PreferredStockSharesAuthorized": {
     "auth_ref": [
      "r26"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets",
      "http://www.f5.com/role/ConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_PreferredStockSharesOutstanding": {
     "auth_ref": [
      "r26"
     ],
     "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",
        "verboseLabel": "Preferred stock, shares outstanding"
       }
      }
     },
     "localname": "PreferredStockSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets",
      "http://www.f5.com/role/ConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_PreferredStockValue": {
     "auth_ref": [
      "r26"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest",
       "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",
        "verboseLabel": "Preferred stock, no par value; 10,000 shares authorized, no shares outstanding"
       }
      }
     },
     "localname": "PreferredStockValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PrepaidExpenseCurrent": {
     "auth_ref": [
      "r4",
      "r6",
      "r181"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsOtherCurrentAssetsDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_OtherAssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of asset related to consideration paid in advance for costs that provide economic benefits within a future period of one year or the normal operating cycle, if longer.",
        "label": "Prepaid Expense, Current",
        "terseLabel": "Prepaid expenses"
       }
      }
     },
     "localname": "PrepaidExpenseCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsOtherCurrentAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PriorPeriodReclassificationAdjustmentDescription": {
     "auth_ref": [
      "r0"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for reclassifications that affects the comparability of the financial statements.",
        "label": "Reclassification, Policy [Policy Text Block]",
        "terseLabel": "Prior Period Reclassifications"
       }
      }
     },
     "localname": "PriorPeriodReclassificationAdjustmentDescription",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ProceedsFromIssuanceOfLongTermDebt": {
     "auth_ref": [
      "r98"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.",
        "label": "Proceeds from Issuance of Long-term Debt",
        "terseLabel": "Proceeds from term debt agreement"
       }
      }
     },
     "localname": "ProceedsFromIssuanceOfLongTermDebt",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions": {
     "auth_ref": [
      "r97",
      "r299"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cash inflow from issuance of shares under share-based payment arrangement. Includes, but is not limited to, option exercised.",
        "label": "Proceeds, Issuance of Shares, Share-based Payment Arrangement, Including Option Exercised",
        "verboseLabel": "Proceeds from the exercise of stock options and purchases of stock under employee stock purchase plan"
       }
      }
     },
     "localname": "ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities": {
     "auth_ref": [
      "r90",
      "r91",
      "r170"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "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 Debt Securities, Available-for-sale",
        "terseLabel": "Maturities of investments"
       }
      }
     },
     "localname": "ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities": {
     "auth_ref": [
      "r92",
      "r170"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities.",
        "label": "Proceeds from Sale of Available-for-sale Securities",
        "terseLabel": "Sales of investments"
       }
      }
     },
     "localname": "ProceedsFromSaleOfAvailableForSaleSecurities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromSaleOfProductiveAssets": {
     "auth_ref": [
      "r93"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash inflow from the sale of property, plant and equipment (capital expenditures), software, and other intangible assets.",
        "label": "Proceeds from Sale of Productive Assets",
        "terseLabel": "Cash provided by sale of fixed assets"
       }
      }
     },
     "localname": "ProceedsFromSaleOfProductiveAssets",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProductMember": {
     "auth_ref": [
      "r252"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Article or substance produced by nature, labor or machinery.",
        "label": "Product [Member]",
        "terseLabel": "Product [Member]"
       }
      }
     },
     "localname": "ProductMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails",
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Property, Plant and Equipment [Abstract]",
        "terseLabel": "Property, Plant and Equipment [Abstract]"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentByTypeAxis": {
     "auth_ref": [
      "r39",
      "r208"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by type of long-lived, physical assets used to produce goods and services and not intended for resale.",
        "label": "Property, Plant and Equipment, Type [Axis]",
        "terseLabel": "Property, Plant and Equipment by Type [Axis]"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentByTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesNarrativeDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentGross": {
     "auth_ref": [
      "r38",
      "r206"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsPropertyandEquipmentDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_PropertyPlantAndEquipmentNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business 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, Gross",
        "terseLabel": "Property and equipment, gross",
        "totalLabel": "Property, Plant and Equipment, Gross"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentGross",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsPropertyandEquipmentDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentLineItems": {
     "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": "Property, Plant and Equipment [Line Items]",
        "terseLabel": "Property, Plant and Equipment [Line Items]"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsNarrativeDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "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 [Member]",
        "terseLabel": "Property, Plant and Equipment [Member]"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentNet": {
     "auth_ref": [
      "r17",
      "r18",
      "r208",
      "r455"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsPropertyandEquipmentDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 1.0,
       "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": "Property, Plant and Equipment, Net",
        "totalLabel": "Property, Plant and Equipment, Net",
        "verboseLabel": "Property and equipment, net"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsPropertyandEquipmentDetails",
      "http://www.f5.com/role/ConsolidatedBalanceSheets",
      "http://www.f5.com/role/SegmentInformationDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentPolicyTextBlock": {
     "auth_ref": [
      "r37",
      "r118",
      "r208"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for long-lived, physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, basis of assets, depreciation and depletion methods used, including composite deprecation, estimated useful lives, capitalization policy, accounting treatment for costs incurred for repairs and maintenance, capitalized interest and the method it is calculated, disposals and impairments.",
        "label": "Property, Plant and Equipment, Policy [Policy Text Block]",
        "terseLabel": "Property, Plant and Equipment",
        "verboseLabel": "Property And Equipment"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsTables",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentTypeDomain": {
     "auth_ref": [
      "r17",
      "r206"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Listing of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.",
        "label": "Property, Plant and Equipment, Type [Domain]",
        "terseLabel": "Property, Plant and Equipment, Type [Domain]"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesNarrativeDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentUsefulLife": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.",
        "label": "Property, Plant and Equipment, Useful Life",
        "terseLabel": "Property and equipment, useful life"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentUsefulLife",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_PurchaseCommitmentExcludingLongtermCommitmentAxis": {
     "auth_ref": [
      "r23",
      "r430",
      "r451"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by arrangement, in which the entity has agreed to expend funds to procure goods or services from one or more suppliers.",
        "label": "Purchase Commitment, Excluding Long-term Commitment [Axis]",
        "terseLabel": "Purchase Commitment, Excluding Long-term Commitment [Axis]"
       }
      }
     },
     "localname": "PurchaseCommitmentExcludingLongtermCommitmentAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PurchaseCommitmentExcludingLongtermCommitmentDomain": {
     "auth_ref": [
      "r23",
      "r430",
      "r451"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This item is intended to be populated, by the entity, with Members identifying each purchase commitment about which information required or determined to be disclosed is being provided. If only one such commitment exists, this item may be used to capture such information; if multiple commitments exist, this item is the dimensional default, which will aggregate such information, as appropriate.",
        "label": "Purchase Commitment, Excluding Long-term Commitment [Domain]",
        "terseLabel": "Purchase Commitment, Excluding Long-term Commitment [Domain]"
       }
      }
     },
     "localname": "PurchaseCommitmentExcludingLongtermCommitmentDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PurchaseCommitmentMember": {
     "auth_ref": [
      "r23",
      "r430",
      "r451"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier. Excludes long-term commitments.",
        "label": "Purchase Commitment [Member]",
        "terseLabel": "Purchase Commitment [Member]"
       }
      }
     },
     "localname": "PurchaseCommitmentMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PurchaseCommitmentRemainingMinimumAmountCommitted": {
     "auth_ref": [
      "r23",
      "r430",
      "r451"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Minimum amount to be expended to satisfy the terms of arrangements in which the entity has agreed to expend funds to procure goods or services, excluding long-term purchase commitments or unconditional purchase obligations.",
        "label": "Purchase Commitment, Remaining Minimum Amount Committed",
        "terseLabel": "Purchase Commitment, Remaining Minimum Amount Committed"
       }
      }
     },
     "localname": "PurchaseCommitmentRemainingMinimumAmountCommitted",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/CommitmentsAndContingenciesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_QuarterlyFinancialDataAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Quarterly Financial Data [Abstract]",
        "terseLabel": "Quarterly Financial Data [Abstract]"
       }
      }
     },
     "localname": "QuarterlyFinancialDataAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_QuarterlyFinancialInformationTextBlock": {
     "auth_ref": [
      "r142"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for quarterly financial data. Includes, but is not limited to, tabular presentation of financial information for fiscal quarters, effect of year-end adjustments, and an explanation of matters or transactions that affect comparability of the information.",
        "label": "Quarterly Financial Information [Text Block]",
        "terseLabel": "Quarterly Results Of Operations (Unaudited)"
       }
      }
     },
     "localname": "QuarterlyFinancialInformationTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnaudited"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward": {
     "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": "Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]",
        "terseLabel": "Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]"
       }
      }
     },
     "localname": "ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfReconciliationOfBeginningAndEndingAmountOfUnrecognizedTaxBenefitsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RepaymentsOfLongTermDebt": {
     "auth_ref": [
      "r100"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.",
        "label": "Repayments of Long-term Debt",
        "negatedTerseLabel": "Payments on term debt agreement"
       }
      }
     },
     "localname": "RepaymentsOfLongTermDebt",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ResearchAndDevelopmentExpense": {
     "auth_ref": [
      "r305",
      "r476"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedIncomeStatements": {
       "order": 2.0,
       "parentTag": "us-gaap_OperatingExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.",
        "label": "Research and Development Expense",
        "terseLabel": "Research and development"
       }
      }
     },
     "localname": "ResearchAndDevelopmentExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ResearchAndDevelopmentExpensePolicy": {
     "auth_ref": [
      "r118",
      "r305"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for costs it has incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process.",
        "label": "Research and Development Expense, Policy [Policy Text Block]",
        "verboseLabel": "Research And Development"
       }
      }
     },
     "localname": "ResearchAndDevelopmentExpensePolicy",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_RestrictedCash": {
     "auth_ref": [
      "r116",
      "r425",
      "r452"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsCashCashEquivalentsandRestrictedCashDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cash restricted as to withdrawal or usage. 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.",
        "label": "Restricted Cash",
        "terseLabel": "Restricted Cash"
       }
      }
     },
     "localname": "RestrictedCash",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsCashCashEquivalentsandRestrictedCashDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RestrictedStockAwardForfeituresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Restricted Stock Award, Forfeitures [Abstract]",
        "terseLabel": "Restricted Stock Award"
       }
      }
     },
     "localname": "RestrictedStockAwardForfeituresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RestrictedStockUnitsRSUMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Share instrument which is convertible to stock or an equivalent amount of cash, after a specified period of time or when specified performance conditions are met.",
        "label": "Restricted Stock Units (RSUs) [Member]",
        "terseLabel": "Restricted Stock Units (RSUs) [Member]"
       }
      }
     },
     "localname": "RestrictedStockUnitsRSUMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RestructuringAndRelatedActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Restructuring and Related Activities [Abstract]",
        "terseLabel": "Restructuring and Related Activities [Abstract]"
       }
      }
     },
     "localname": "RestructuringAndRelatedActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_RestructuringAndRelatedActivitiesDisclosureTextBlock": {
     "auth_ref": [
      "r220"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for restructuring and related activities. Description of restructuring activities such as exit and disposal activities, include facts and circumstances leading to the plan, the expected plan completion date, the major types of costs associated with the plan activities, total expected costs, the accrual balance at the end of the period, and the periods over which the remaining accrual will be settled.",
        "label": "Restructuring and Related Activities Disclosure [Text Block]",
        "terseLabel": "Restructuring Charges"
       }
      }
     },
     "localname": "RestructuringAndRelatedActivitiesDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RestructuringCharges"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_RestructuringCharges": {
     "auth_ref": [
      "r108",
      "r211",
      "r215",
      "r219"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedIncomeStatements": {
       "order": 4.0,
       "parentTag": "us-gaap_OperatingExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.",
        "label": "Restructuring Charges",
        "terseLabel": "Restructuring charges"
       }
      }
     },
     "localname": "RestructuringCharges",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails",
      "http://www.f5.com/role/RestructuringChargesDetails",
      "http://www.f5.com/role/RestructuringChargesRestructuringActivityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RestructuringReserve": {
     "auth_ref": [
      "r212",
      "r217"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.",
        "label": "Restructuring Reserve",
        "periodEndLabel": "Accrued Expenses (Ending Balance)",
        "periodStartLabel": "Accrued Expenses (Beginning Balance)",
        "terseLabel": "Restructuring Reserve"
       }
      }
     },
     "localname": "RestructuringReserve",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RestructuringChargesDetails",
      "http://www.f5.com/role/RestructuringChargesRestructuringActivityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RestructuringReserveSettledWithoutCash2": {
     "auth_ref": [
      "r211",
      "r216"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of decrease in the reserve for full or partial settlement through consideration other than cash.",
        "label": "Restructuring Reserve, Settled without Cash",
        "negatedTerseLabel": "Non-cash items"
       }
      }
     },
     "localname": "RestructuringReserveSettledWithoutCash2",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RestructuringChargesRestructuringActivityDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RetainedEarningsAccumulatedDeficit": {
     "auth_ref": [
      "r29",
      "r233",
      "r453"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest",
       "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"
       }
      }
     },
     "localname": "RetainedEarningsAccumulatedDeficit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RetainedEarningsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cumulative amount of the reporting entity's undistributed earnings or deficit.",
        "label": "Retained Earnings [Member]",
        "terseLabel": "Retained Earnings"
       }
      }
     },
     "localname": "RetainedEarningsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Revenue from Contract with Customer [Abstract]",
        "terseLabel": "Revenue from Contract with Customer [Abstract]"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax": {
     "auth_ref": [
      "r248",
      "r249"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedIncomeStatements": {
       "order": 2.0,
       "parentTag": "us-gaap_GrossProfit",
       "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": "Net revenues",
        "verboseLabel": "Net revenues"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerExcludingAssessedTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails",
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerTextBlock": {
     "auth_ref": [
      "r256"
     ],
     "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 Contract with Customers"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomers"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_RevenueRecognitionAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Revenue Recognition [Abstract]",
        "terseLabel": "Revenue Recognition"
       }
      }
     },
     "localname": "RevenueRecognitionAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RevenueRecognitionPolicyTextBlock": {
     "auth_ref": [
      "r119",
      "r120"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for revenue. Includes revenue from contract with customer and from other sources.",
        "label": "Revenue [Policy Text Block]",
        "terseLabel": "Revenue Recognition"
       }
      }
     },
     "localname": "RevenueRecognitionPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_RevenueRemainingPerformanceObligation": {
     "auth_ref": [
      "r246"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of transaction price allocated to performance obligation that has not been recognized as revenue.",
        "label": "Revenue, Remaining Performance Obligation, Amount",
        "terseLabel": "Revenue, Remaining Performance Obligation, Amount"
       }
      }
     },
     "localname": "RevenueRemainingPerformanceObligation",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersRemainingPerformanceObligationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems": {
     "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": "Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]",
        "terseLabel": "Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]"
       }
      }
     },
     "localname": "RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersRemainingPerformanceObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1": {
     "auth_ref": [
      "r247"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Period in which remaining performance obligation is expected to be recognized as revenue, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.",
        "label": "Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period",
        "terseLabel": "Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period"
       }
      }
     },
     "localname": "RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersRemainingPerformanceObligationsDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis": {
     "auth_ref": [
      "r247"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Start date of time band for expected timing of satisfaction of remaining performance obligation, in CCYY-MM-DD format.",
        "label": "Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]",
        "terseLabel": "Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]"
       }
      }
     },
     "localname": "RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersRemainingPerformanceObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about expected timing for satisfying remaining performance obligation.",
        "label": "Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table]",
        "terseLabel": "Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table]"
       }
      }
     },
     "localname": "RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersRemainingPerformanceObligationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RevenueRemainingPerformanceObligationPercentage": {
     "auth_ref": [
      "r247"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Percentage of remaining performance obligation to total remaining performance obligation not recognized as revenue.",
        "label": "Revenue, Remaining Performance Obligation, Percentage",
        "terseLabel": "Revenue, Remaining Performance Obligation, Percentage"
       }
      }
     },
     "localname": "RevenueRemainingPerformanceObligationPercentage",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RevenuefromContractswithCustomersRemainingPerformanceObligationsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_RevenuesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Revenues [Abstract]",
        "terseLabel": "Net revenues"
       }
      }
     },
     "localname": "RevenuesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RevolvingCreditFacilityMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Arrangement in which loan proceeds can continuously be obtained following repayments, but the total amount borrowed cannot exceed a specified maximum amount.",
        "label": "Revolving Credit Facility [Member]",
        "terseLabel": "Revolving Credit Facility [Member]"
       }
      }
     },
     "localname": "RevolvingCreditFacilityMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability": {
     "auth_ref": [
      "r410",
      "r415"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase in right-of-use asset obtained in exchange for operating lease liability.",
        "label": "Right-of-Use Asset Obtained in Exchange for Operating Lease Liability",
        "terseLabel": "Right-of-use assets obtained in exchange for lease obligations"
       }
      }
     },
     "localname": "RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RisksAndUncertaintiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Risks and Uncertainties [Abstract]",
        "terseLabel": "Concentration of Credit Risk"
       }
      }
     },
     "localname": "RisksAndUncertaintiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SalesRevenueNetMember": {
     "auth_ref": [
      "r149"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Revenue from sale of product and rendering of service and other sources of income, when it serves as benchmark in concentration of risk calculation.",
        "label": "Revenue Benchmark [Member]",
        "terseLabel": "Revenue Benchmark [Member]"
       }
      }
     },
     "localname": "SalesRevenueNetMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ScheduleOfAccruedLiabilitiesTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the components of accrued liabilities.",
        "label": "Schedule of Accrued Liabilities [Table Text Block]",
        "verboseLabel": "Accrued Liabilities"
       }
      }
     },
     "localname": "ScheduleOfAccruedLiabilitiesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems": {
     "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, Available-for-sale [Line Items]",
        "terseLabel": "Debt Securities, Available-for-sale [Line Items]"
       }
      }
     },
     "localname": "ScheduleOfAvailableForSaleSecuritiesLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "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]",
        "verboseLabel": "Schedule Of Short-Term And Long-Term Investments"
       }
      }
     },
     "localname": "ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable": {
     "auth_ref": [
      "r348",
      "r349"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule reflecting each material business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities.",
        "label": "Schedule of Business Acquisitions, by Acquisition [Table]",
        "terseLabel": "Schedule of Business Acquisitions, by Acquisition [Table]"
       }
      }
     },
     "localname": "ScheduleOfBusinessAcquisitionsByAcquisitionTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails",
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfCashAndCashEquivalentsTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the components of cash and cash equivalents.",
        "label": "Schedule of Cash and Cash Equivalents [Table Text Block]",
        "terseLabel": "Cash, Cash Equivalents and Restricted Cash"
       }
      }
     },
     "localname": "ScheduleOfCashAndCashEquivalentsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock": {
     "auth_ref": [
      "r339"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the components of income tax expense attributable to continuing operations for each year presented including, but not limited to: current tax expense (benefit), deferred tax expense (benefit), investment tax credits, government grants, the benefits of operating loss carryforwards, tax expense that results from allocating certain tax benefits either directly to contributed capital or to reduce goodwill or other noncurrent intangible assets of an acquired entity, adjustments of a deferred tax liability or asset for enacted changes in tax laws or rates or a change in the tax status of the entity, and adjustments of the beginning-of-the-year balances of a valuation allowance because of a change in circumstances that causes a change in judgment about the realizability of the related deferred tax asset in future years.",
        "label": "Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]",
        "verboseLabel": "Schedule Of Provision For Income Taxes (Benefit)"
       }
      }
     },
     "localname": "ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock": {
     "auth_ref": [
      "r331"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the components of net deferred tax asset or liability recognized in an entity's statement of financial position, including the following: the total of all deferred tax liabilities, the total of all deferred tax assets, the total valuation allowance recognized for deferred tax assets.",
        "label": "Schedule of Deferred Tax Assets and Liabilities [Table Text Block]",
        "verboseLabel": "Schedule Of Tax Effects To Deferred Tax Assets And Liabilities"
       }
      }
     },
     "localname": "ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock": {
     "auth_ref": [
      "r137"
     ],
     "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",
        "verboseLabel": "Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]"
       }
      }
     },
     "localname": "ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/AccountingPoliciesTables",
      "http://www.f5.com/role/NetIncomePerShareTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock": {
     "auth_ref": [
      "r315"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the reconciliation using percentage or dollar amounts of the reported amount of income tax expense attributable to continuing operations for the year to the amount of income tax expense that would result from applying domestic federal statutory tax rates to pretax income from continuing operations.",
        "label": "Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]",
        "verboseLabel": "Schedule Of Effective Tax Rate Differs From The U.S. Federal Statutory Rate"
       }
      }
     },
     "localname": "ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfFairValueOfSeparateAccountsByMajorCategoryOfInvestmentTable": {
     "auth_ref": [
      "r464",
      "r465"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about fair value of asset supporting separate account.",
        "label": "Fair Value, Separate Account Investment [Table]",
        "terseLabel": "Fair Value, Separate Account Investment [Table]"
       }
      }
     },
     "localname": "ScheduleOfFairValueOfSeparateAccountsByMajorCategoryOfInvestmentTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsTables"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable": {
     "auth_ref": [
      "r193",
      "r197"
     ],
     "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]",
        "terseLabel": "Schedule of Finite-Lived Intangible Assets by Major Class [Table]"
       }
      }
     },
     "localname": "ScheduleOfFiniteLivedIntangibleAssetsTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock": {
     "auth_ref": [
      "r193",
      "r197"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of assets, excluding financial assets and goodwill, lacking physical substance with a finite life, by either major class or business segment.",
        "label": "Schedule of Finite-Lived Intangible Assets [Table Text Block]",
        "terseLabel": "Intangible Assets"
       }
      }
     },
     "localname": "ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock": {
     "auth_ref": [
      "r397"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of future minimum payments required in the aggregate and for each of the five succeeding fiscal years for operating leases having initial or remaining noncancelable lease terms in excess of one year and the total minimum rentals to be received in the future under noncancelable subleases as of the balance sheet date.",
        "label": "Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]",
        "terseLabel": "Future Minimum Rental Payments for Operating Leases"
       }
      }
     },
     "localname": "ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfGoodwillTextBlock": {
     "auth_ref": [
      "r190",
      "r191"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule.",
        "label": "Schedule of Goodwill [Table Text Block]",
        "terseLabel": "Goodwill"
       }
      }
     },
     "localname": "ScheduleOfGoodwillTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock": {
     "auth_ref": [
      "r125"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of income before income tax between domestic and foreign jurisdictions.",
        "label": "Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]",
        "verboseLabel": "Components Of Income Before Income Taxes"
       }
      }
     },
     "localname": "ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfInventoryCurrentTableTextBlock": {
     "auth_ref": [
      "r12",
      "r32",
      "r33",
      "r34"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the carrying amount as of the balance sheet date of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.",
        "label": "Schedule of Inventory, Current [Table Text Block]",
        "terseLabel": "Schedule of Inventories",
        "verboseLabel": "Inventories"
       }
      }
     },
     "localname": "ScheduleOfInventoryCurrentTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/AccountingPoliciesTables",
      "http://www.f5.com/role/BalanceSheetDetailsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems": {
     "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": "Net Investment Income [Line Items]",
        "terseLabel": "Net Investment Income [Line Items]"
       }
      }
     },
     "localname": "ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryTable": {
     "auth_ref": [
      "r86",
      "r88",
      "r89",
      "r459"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about investment income, including, but not limited to, interest and dividend income and amortization of discount (premium) derived from debt and equity securities. Excludes realized and unrealized gain (loss) on investments.",
        "label": "Investment Income [Table]",
        "terseLabel": "Investment Income [Table]"
       }
      }
     },
     "localname": "ScheduleOfInvestmentIncomeReportedAmountsByCategoryTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfInvestmentsLineItems": {
     "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": "Schedule of Investments [Line Items]",
        "terseLabel": "Schedule of Investments [Line Items]"
       }
      }
     },
     "localname": "ScheduleOfInvestmentsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsTables"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock": {
     "auth_ref": [
      "r225"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the combined aggregate amount of maturities and sinking fund requirements for all long-term borrowings for each of the five years following the date of the latest balance sheet date presented.",
        "label": "Schedule of Maturities of Long-term Debt [Table Text Block]",
        "terseLabel": "Schedule of Maturities of Long-term Debt"
       }
      }
     },
     "localname": "ScheduleOfMaturitiesOfLongTermDebtTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock": {
     "auth_ref": [
      "r278"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the changes in outstanding nonvested restricted stock units.",
        "label": "Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]",
        "terseLabel": "Schedule of Nonvested Restricted Stock Units Activity"
       }
      }
     },
     "localname": "ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfOtherAssetsTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the carrying amounts of other assets. This disclosure includes other current assets and other noncurrent assets.",
        "label": "Schedule of Other Assets [Table Text Block]",
        "verboseLabel": "Other Assets"
       }
      }
     },
     "localname": "ScheduleOfOtherAssetsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfOtherCurrentAssetsTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the carrying amounts of other current assets.",
        "label": "Schedule of Other Current Assets [Table Text Block]",
        "terseLabel": "Other Current Assets"
       }
      }
     },
     "localname": "ScheduleOfOtherCurrentAssetsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfPropertyPlantAndEquipmentTable": {
     "auth_ref": [
      "r39",
      "r208"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, balances by class of assets, depreciation and depletion expense and method used, including composite depreciation, and accumulated deprecation.",
        "label": "Property, Plant and Equipment [Table]",
        "terseLabel": "Schedule of Property, Plant and Equipment [Table]"
       }
      }
     },
     "localname": "ScheduleOfPropertyPlantAndEquipmentTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsNarrativeDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfQuarterlyFinancialInformationTableTextBlock": {
     "auth_ref": [
      "r141"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of quarterly financial data. Includes, but is not limited to, financial information for fiscal quarters, cumulative effect of a change in accounting principle and earnings per share data.",
        "label": "Quarterly Financial Information [Table Text Block]",
        "terseLabel": "Schedule Of Quarterly Results Of Operations"
       }
      }
     },
     "localname": "ScheduleOfQuarterlyFinancialInformationTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock": {
     "auth_ref": [
      "r352"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the amounts recognized as of the acquisition date for each major class of assets acquired and liabilities assumed. May include but not limited to the following: (a) acquired receivables; (b) contingencies recognized at the acquisition date; and (c) the fair value of noncontrolling interests in the acquiree.",
        "label": "Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]",
        "terseLabel": "Schedule of Recognized Identified Assets Acquired and Liabilities Assumed"
       }
      }
     },
     "localname": "ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BusinessCombinationsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock": {
     "auth_ref": [
      "r213",
      "r214",
      "r218"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of costs incurred for restructuring including, but not limited to, exit and disposal activities, remediation, implementation, integration, asset impairment, and charges against earnings from the write-down of assets.",
        "label": "Restructuring and Related Costs [Table Text Block]",
        "terseLabel": "Restructuring and Related Costs"
       }
      }
     },
     "localname": "ScheduleOfRestructuringAndRelatedCostsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/RestructuringChargesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfRevenueByMajorCustomersByReportingSegmentsTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the extent of the entity's reliance on its major customers, if revenues from transactions with a single external customer amount to 10 percent or more of entity revenues, including the disclosure of that fact, the total amount of revenues from each such customer, and the identity of the reportable segment or segments reporting the revenues. The entity need not disclose the identity of a major customer or the amount of revenues that each segment reports from that customer. For these purposes, a group of companies known to the entity to be under common control is considered a single customer, and the federal government, a state government, a local government such as a county or municipality, or a foreign government is each considered a single customer.",
        "label": "Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]",
        "terseLabel": "Schedule of Revenue by Major Customers by Reporting Segments"
       }
      }
     },
     "localname": "ScheduleOfRevenueByMajorCustomersByReportingSegmentsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfRevenueFromExternalCustomersAttributedToForeignCountriesByGeographicAreaTextBlock": {
     "auth_ref": [
      "r82",
      "r162"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the names of foreign countries from which revenue is material and the amount of revenue from external customers attributed to those countries. An entity may also provide subtotals of geographic information about groups of countries.",
        "label": "Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Table Text Block]",
        "verboseLabel": "Schedule Of Revenues By Geographic Region"
       }
      }
     },
     "localname": "ScheduleOfRevenueFromExternalCustomersAttributedToForeignCountriesByGeographicAreaTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable": {
     "auth_ref": [
      "r154",
      "r158",
      "r159",
      "r160",
      "r190"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock": {
     "auth_ref": [
      "r154",
      "r158",
      "r159",
      "r160",
      "r190"
     ],
     "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 Revenues by Systems and Software"
       }
      }
     },
     "localname": "ScheduleOfSegmentReportingInformationBySegmentTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingTableTextBlock": {
     "auth_ref": [
      "r288"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of number, weighted-average exercise price or conversion ratio, aggregate intrinsic value, and weighted-average remaining contractual term for outstanding options that are fully vested and expected to vest. 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 Arrangements by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding [Table Text Block]",
        "terseLabel": "Schedule Of Outstanding Stock Options Currently Exercisable, Vested And Expected To Vest"
       }
      }
     },
     "localname": "ScheduleOfShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable": {
     "auth_ref": [
      "r266",
      "r298"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock": {
     "auth_ref": [
      "r271"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the number and weighted-average grant date fair value for restricted stock units that were outstanding at the beginning and end of the year, and the number of restricted stock units that were granted, vested, or forfeited during the year.",
        "label": "Share-based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block]",
        "terseLabel": "Schedule Of Summary Of Restricted Stock Unit Activity"
       }
      }
     },
     "localname": "ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock": {
     "auth_ref": [
      "r271",
      "r284",
      "r287"
     ],
     "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": "Share-based Payment Arrangement, Option, Activity [Table Text Block]",
        "terseLabel": "Schedule Of Stock Option Activity"
       }
      }
     },
     "localname": "ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfShareBasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock": {
     "auth_ref": [
      "r290"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the significant assumptions used during the year to estimate the fair value of employee stock purchase plans, including, but not limited to: (a) expected term, (b) expected volatility of the entity's shares, (c) expected dividends, (d) risk-free rate(s), and (e) discount for post-vesting restrictions.",
        "label": "Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]",
        "terseLabel": "Schedule Of Assumptions In Determining The Fair Value Of Shares Issued Under The Employee Stock Purchase Plan"
       }
      }
     },
     "localname": "ScheduleOfShareBasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock": {
     "auth_ref": [
      "r290"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the significant assumptions used during the year to estimate the fair value of stock options, including, but not limited to: (a) expected term of share options and similar instruments, (b) expected volatility of the entity's shares, (c) expected dividends, (d) risk-free rate(s), and (e) discount for post-vesting restrictions.",
        "label": "Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]",
        "terseLabel": "Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions"
       }
      }
     },
     "localname": "ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfTreasuryStockByClassTextBlock": {
     "auth_ref": [
      "r234",
      "r235",
      "r236",
      "r237"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of treasury stock, including, but not limited to, average cost per share, description of share repurchase program, shares repurchased, shares held for each class of treasury stock.",
        "label": "Class of Treasury Stock [Table Text Block]",
        "terseLabel": "Common Stock Repurchased and Retired"
       }
      }
     },
     "localname": "ScheduleOfTreasuryStockByClassTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShareholdersEquityTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock": {
     "auth_ref": [
      "r172"
     ],
     "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]",
        "verboseLabel": "Schedule Of Investments That Have Been In A Continuous Unrealized Loss Position"
       }
      }
     },
     "localname": "ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock": {
     "auth_ref": [
      "r197"
     ],
     "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]",
        "verboseLabel": "Estimated Amortization Expense For Intangible Assets"
       }
      }
     },
     "localname": "ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SegmentReportingAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Segment Reporting [Abstract]",
        "terseLabel": "Segment Reporting [Abstract]"
       }
      }
     },
     "localname": "SegmentReportingAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SegmentReportingDisclosureTextBlock": {
     "auth_ref": [
      "r166"
     ],
     "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": "Segment Reporting Disclosure"
       }
      }
     },
     "localname": "SegmentReportingDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformation"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SegmentInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SegmentReportingPolicyPolicyTextBlock": {
     "auth_ref": [
      "r118"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for segment reporting.",
        "label": "Segment Reporting, Policy [Policy Text Block]",
        "terseLabel": "Segments"
       }
      }
     },
     "localname": "SegmentReportingPolicyPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SegmentsGeographicalAreasAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Segments, Geographical Areas [Abstract]",
        "terseLabel": "Segments, Geographical Areas [Abstract]"
       }
      }
     },
     "localname": "SegmentsGeographicalAreasAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_SellingAndMarketingExpense": {
     "auth_ref": [],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedIncomeStatements": {
       "order": 1.0,
       "parentTag": "us-gaap_OperatingExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The aggregate total amount of expenses directly related to the marketing or selling of products or services.",
        "label": "Selling and Marketing Expense",
        "terseLabel": "Sales and marketing"
       }
      }
     },
     "localname": "SellingAndMarketingExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ServiceMember": {
     "auth_ref": [
      "r252"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Assistance, including, but not limited to, technology, license and maintenance, license and service, maintenance, oil and gas, and financial service.",
        "label": "Service [Member]",
        "terseLabel": "Service [Member]"
       }
      }
     },
     "localname": "ServiceMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ShareBasedCompensation": {
     "auth_ref": [
      "r107"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of noncash expense for share-based payment arrangement.",
        "label": "Share-based Payment Arrangement, Noncash Expense",
        "terseLabel": "Stock-based compensation"
       }
      }
     },
     "localname": "ShareBasedCompensation",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Share-based Payment Arrangement, Noncash Expense [Abstract]",
        "terseLabel": "Share-based Payment Arrangement, Noncash Expense [Abstract]"
       }
      }
     },
     "localname": "ShareBasedCompensationAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1": {
     "auth_ref": [
      "r267"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate": {
     "auth_ref": [
      "r298"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Discount rate from fair value on offering date that participants pay for shares.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date",
        "terseLabel": "Percentage of common stock lesser of the fair market value"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod": {
     "auth_ref": [
      "r276"
     ],
     "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",
        "negatedLabel": "Outstanding Stock Units, Units cancelled"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r282"
     ],
     "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",
        "terseLabel": "Weighted Average Grant Date Fair Value, Units cancelled"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod": {
     "auth_ref": [
      "r280"
     ],
     "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",
        "negatedLabel": "Awards Available for Grant, Granted",
        "terseLabel": "Equity Instruments Other than Options, Grants in Period",
        "verboseLabel": "Outstanding Stock Units, Units granted"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfEquityBasedAwardsIncludingStockOptionsAndRestrictedStockUnitsDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r280"
     ],
     "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": "Weighted Average Grant Date Fair Value, Units granted"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber": {
     "auth_ref": [
      "r279"
     ],
     "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": "Outstanding Stock Units, Ending balance",
        "periodStartLabel": "Outstanding Stock Units, Beginning balance",
        "terseLabel": "Outstanding stock units"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails"
     ],
     "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": "Outstanding Restricted Stock Units"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r279"
     ],
     "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": "Weighted Average Grant Date Fair Value, Ending balance",
        "periodStartLabel": "Weighted Average Grant Date Fair Value, Beginning balance",
        "terseLabel": "Weighted Average Grant Date Fair Value"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails"
     ],
     "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\u00a0Date Fair Value"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod": {
     "auth_ref": [
      "r281"
     ],
     "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",
        "negatedLabel": "Outstanding Stock Units, Units vested"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue": {
     "auth_ref": [
      "r286"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value",
        "terseLabel": "Fair market value of restricted stock vested"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r281"
     ],
     "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": "Weighted Average Grant Date Fair Value, Units vested"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]",
        "terseLabel": "Fair Value Assumptions"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate": {
     "auth_ref": [
      "r293"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate",
        "terseLabel": "Expected dividend"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate": {
     "auth_ref": [
      "r292"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate",
        "terseLabel": "Expected volatility"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate": {
     "auth_ref": [
      "r294"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The risk-free interest rate assumption that is used in valuing an option on its own shares.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate",
        "terseLabel": "Risk-free interest rate"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate": {
     "auth_ref": [
      "r298"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate",
        "terseLabel": "Percentage of base compensation for which employees can acquire shares of common stock"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee": {
     "auth_ref": [
      "r298"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The highest quantity of shares an employee can purchase under the plan per period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares Per Employee",
        "terseLabel": "Maximum shares allowed for purchase by employee in period"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized": {
     "auth_ref": [
      "r268"
     ],
     "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"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant": {
     "auth_ref": [
      "r298"
     ],
     "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",
        "periodEndLabel": "Awards Available for Grant, Ending balance",
        "periodStartLabel": "Awards Available for Grant, Beginning balance"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfEquityBasedAwardsIncludingStockOptionsAndRestrictedStockUnitsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber": {
     "auth_ref": [
      "r274"
     ],
     "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, Number of Shares"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfOutstandingStockOptionsCurrentlyExercisableVestedAndExpectedToVestDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice": {
     "auth_ref": [
      "r274"
     ],
     "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, Weighted Average Exercise Price per Share"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfOutstandingStockOptionsCurrentlyExercisableVestedAndExpectedToVestDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue": {
     "auth_ref": [
      "r286"
     ],
     "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": "Total intrinsic value of options exercised"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod": {
     "auth_ref": [
      "r277"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period",
        "negatedLabel": "Number of Shares, Options cancelled"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfStockOptionActivityDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice": {
     "auth_ref": [
      "r277"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Weighted average price of options that were either forfeited or expired.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price",
        "terseLabel": "Weighted Average Exercise Price per Share, Options cancelled"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfStockOptionActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Gross number of share options (or share units) granted during the period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross",
        "terseLabel": "Number of Shares, Options granted"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfStockOptionActivityDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue": {
     "auth_ref": [
      "r298"
     ],
     "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",
        "terseLabel": "Stock options outstanding, Aggregate Intrinsic Value"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfOutstandingStockOptionsCurrentlyExercisableVestedAndExpectedToVestDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber": {
     "auth_ref": [
      "r273",
      "r298"
     ],
     "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": "Number of Shares, Ending balance",
        "periodStartLabel": "Number of Shares, Beginning balance",
        "verboseLabel": "Stock options outstanding"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfOutstandingStockOptionsCurrentlyExercisableVestedAndExpectedToVestDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfStockOptionActivityDetails"
     ],
     "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": "Number\u00a0of Shares"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfStockOptionActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice": {
     "auth_ref": [
      "r272"
     ],
     "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": "Weighted Average Exercise Price per Share, Ending balance",
        "periodStartLabel": "Weighted Average Exercise Price per Share, Beginning balance",
        "terseLabel": "Stock options outstanding, Weighted Average Exercise Price per Share"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfOutstandingStockOptionsCurrentlyExercisableVestedAndExpectedToVestDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfStockOptionActivityDetails"
     ],
     "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\u00a0Price per Share"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfStockOptionActivityDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue": {
     "auth_ref": [
      "r289"
     ],
     "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 exercisable or convertible options. 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, Exercisable, Aggregate Intrinsic Value",
        "terseLabel": "Vested and expected to vest, Aggregate Intrinsic Value"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfOutstandingStockOptionsCurrentlyExercisableVestedAndExpectedToVestDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice": {
     "auth_ref": [
      "r289"
     ],
     "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 exercisable or convertible options. 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, Exercisable, Weighted Average Exercise Price",
        "terseLabel": "Vested and expected to vest, Weighted Average Exercise Price per Share"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfOutstandingStockOptionsCurrentlyExercisableVestedAndExpectedToVestDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber": {
     "auth_ref": [
      "r288"
     ],
     "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": "Vested and expected to vest, Number of Shares"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfOutstandingStockOptionsCurrentlyExercisableVestedAndExpectedToVestDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod": {
     "auth_ref": [
      "r298"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of shares issued under share-based payment arrangement.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period",
        "terseLabel": "Shares Issued in Period"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain": {
     "auth_ref": [
      "r263",
      "r269"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Award under share-based payment arrangement.",
        "label": "Award Type [Domain]",
        "terseLabel": "Award Type [Domain]"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfEquityBasedAwardsIncludingStockOptionsAndRestrictedStockUnitsDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfSummaryOfRestrictedStockUnitActivityDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "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": "Weighted Average Exercise Price per Share, Options exercised"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfStockOptionActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.",
        "label": "Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price",
        "terseLabel": "Weighted Average Exercise Price per Share, Options granted"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfStockOptionActivityDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy": {
     "auth_ref": [
      "r118",
      "r266",
      "r270"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for award under share-based payment arrangement. Includes, but is not limited to, methodology and assumption used in measuring cost.",
        "label": "Share-based Payment Arrangement [Policy Text Block]",
        "terseLabel": "Stock-Based Compensation"
       }
      }
     },
     "localname": "ShareBasedCompensationOptionAndIncentivePlansPolicy",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions": {
     "auth_ref": [
      "r283"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.",
        "label": "Share-based Payment Arrangement, Option, Exercise Price Range, Shares Exercisable",
        "terseLabel": "Shares available for purchase under stock option plan"
       }
      }
     },
     "localname": "ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareRepurchaseProgramAxis": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by share repurchase program.",
        "label": "Share Repurchase Program [Axis]",
        "terseLabel": "Share Repurchase Program [Axis]"
       }
      }
     },
     "localname": "ShareRepurchaseProgramAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShareholdersEquityCommonStockRepurchasedandRetiredTableDetails",
      "http://www.f5.com/role/ShareholdersEquityNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareRepurchaseProgramDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Name of the share repurchase program.",
        "label": "Share Repurchase Program [Domain]",
        "terseLabel": "Share Repurchase Program [Domain]"
       }
      }
     },
     "localname": "ShareRepurchaseProgramDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShareholdersEquityCommonStockRepurchasedandRetiredTableDetails",
      "http://www.f5.com/role/ShareholdersEquityNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1": {
     "auth_ref": [
      "r291",
      "r300"
     ],
     "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"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsDetails",
      "http://www.f5.com/role/StockBasedCompensationScheduleofSharebasedPaymentAwardStockOptionsValuationAssumptionsDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1": {
     "auth_ref": [
      "r298"
     ],
     "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, Aggregate Intrinsic Value"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfOutstandingStockOptionsCurrentlyExercisableVestedAndExpectedToVestDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1": {
     "auth_ref": [
      "r298"
     ],
     "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, Weighted Average Remaining Contractual Life (in Years)"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfOutstandingStockOptionsCurrentlyExercisableVestedAndExpectedToVestDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2": {
     "auth_ref": [
      "r288"
     ],
     "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": "Stock options outstanding, Weighted Average Remaining Contractual Life (in Years)"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfOutstandingStockOptionsCurrentlyExercisableVestedAndExpectedToVestDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1": {
     "auth_ref": [
      "r288"
     ],
     "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": "Vested and expected to vest, Weighted Average Remaining Contractual Life (in Years)"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationScheduleOfOutstandingStockOptionsCurrentlyExercisableVestedAndExpectedToVestDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_ShippingAndHandlingCostPolicyTextBlock": {
     "auth_ref": [
      "r117",
      "r118"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for the classification of shipping and handling costs, including whether the costs are included in cost of sales or included in other income statement accounts. If shipping and handling fees are significant and are not included in cost of sales, disclosure includes both the amounts of such costs and the line item on the income statement which includes such costs.",
        "label": "Shipping and Handling Cost, Policy [Policy Text Block]",
        "verboseLabel": "Shipping And Handling"
       }
      }
     },
     "localname": "ShippingAndHandlingCostPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ShortTermDebtTypeAxis": {
     "auth_ref": [
      "r43"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by type of short-term debt arrangement.",
        "label": "Short-term Debt, Type [Axis]",
        "terseLabel": "Short-term Debt, Type [Axis]"
       }
      }
     },
     "localname": "ShortTermDebtTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShortTermDebtTypeDomain": {
     "auth_ref": [
      "r41"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Type of short-term debt arrangement, such as notes, line of credit, commercial paper, asset-based financing, project financing, letter of credit financing.",
        "label": "Short-term Debt, Type [Domain]",
        "terseLabel": "Short-term Debt, Type [Domain]"
       }
      }
     },
     "localname": "ShortTermDebtTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ShortTermInvestments": {
     "auth_ref": [
      "r19",
      "r432",
      "r433",
      "r435",
      "r447"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of investments including trading securities, available-for-sale securities, held-to-maturity securities, and short-term investments classified as other and current.",
        "label": "Short-term Investments",
        "terseLabel": "Short-term investments"
       }
      }
     },
     "localname": "ShortTermInvestments",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShortTermLeaseCost": {
     "auth_ref": [
      "r406",
      "r415"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseExpenseDetails": {
       "order": 2.0,
       "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 expense"
       }
      }
     },
     "localname": "ShortTermLeaseCost",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_SignificantAccountingPoliciesTextBlock": {
     "auth_ref": [
      "r128"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for all significant accounting policies of the reporting entity.",
        "label": "Significant Accounting Policies [Text Block]",
        "terseLabel": "Summary Of Significant Accounting Policies"
       }
      }
     },
     "localname": "SignificantAccountingPoliciesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SoftwareAndSoftwareDevelopmentCostsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Purchased software applications and internally developed software for sale, licensing or long-term internal use.",
        "label": "Software and Software Development Costs [Member]",
        "terseLabel": "Software and Software Development Costs [Member]"
       }
      }
     },
     "localname": "SoftwareAndSoftwareDevelopmentCostsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SoftwareToBeSoldLeasedOrOtherwiseMarketedPolicy": {
     "auth_ref": [
      "r118",
      "r476"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for costs incurred to (1) establish the technological feasibility of a computer software product to be sold, leased, or otherwise marketed; and (2) produce product masters after establishing technological feasibility. This accounting policy also may apply to purchased computer software. This policy also may address the entity's amortization policy for its capitalized computer software costs and how it evaluates such capitalized costs for impairment.",
        "label": "Software to be Sold, Leased, or Otherwise Marketed, Policy [Policy Text Block]",
        "terseLabel": "Software Development Costs"
       }
      }
     },
     "localname": "SoftwareToBeSoldLeasedOrOtherwiseMarketedPolicy",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_StateAndLocalJurisdictionMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Designated tax department of a state or local government entitled to levy and collect income taxes from the entity.",
        "label": "State and Local Jurisdiction [Member]",
        "terseLabel": "State and Local Jurisdiction [Member]"
       }
      }
     },
     "localname": "StateAndLocalJurisdictionMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_StatementEquityComponentsAxis": {
     "auth_ref": [
      "r52",
      "r228"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by component of equity.",
        "label": "Equity Components [Axis]",
        "terseLabel": "Statement, Equity Components [Axis]"
       }
      }
     },
     "localname": "StatementEquityComponentsAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfCashFlowsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Statement of Cash Flows [Abstract]",
        "terseLabel": "Statement of Cash Flows [Abstract]"
       }
      }
     },
     "localname": "StatementOfCashFlowsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfFinancialPositionAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Statement of Financial Position [Abstract]",
        "terseLabel": "Statement of Financial Position [Abstract]"
       }
      }
     },
     "localname": "StatementOfFinancialPositionAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Statement of Comprehensive Income [Abstract]",
        "terseLabel": "Statement of Comprehensive Income [Abstract]"
       }
      }
     },
     "localname": "StatementOfIncomeAndComprehensiveIncomeAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfStockholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Statement of Stockholders' Equity [Abstract]",
        "terseLabel": "Statement of Stockholders' Equity [Abstract]"
       }
      }
     },
     "localname": "StatementOfStockholdersEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementTable": {
     "auth_ref": [],
     "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/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans": {
     "auth_ref": [
      "r26",
      "r27",
      "r228",
      "r233"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of shares issued during the period as a result of an employee stock purchase plan.",
        "label": "Stock Issued During Period, Shares, Employee Stock Purchase Plans",
        "terseLabel": "Issuance of stock under employee stock purchase plan, shares"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures": {
     "auth_ref": [
      "r26",
      "r27",
      "r228",
      "r233"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of shares issued during the period related to Restricted Stock Awards, net of any shares forfeited.",
        "label": "Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures",
        "terseLabel": "Issuance of restricted stock, shares"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised": {
     "auth_ref": [
      "r26",
      "r27",
      "r228",
      "r233",
      "r275"
     ],
     "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",
        "negatedLabel": "Number of Shares, Options exercised",
        "terseLabel": "Exercise of employee stock options, shares"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodSharesStockOptionsExercised",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity",
      "http://www.f5.com/role/StockBasedCompensationScheduleOfStockOptionActivityDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan": {
     "auth_ref": [
      "r26",
      "r27",
      "r228",
      "r233"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Aggregate change in value for stock issued during the period as a result of employee stock purchase plan.",
        "label": "Stock Issued During Period, Value, Employee Stock Purchase Plan",
        "terseLabel": "Issuance of stock under employee stock purchase plan"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodValueEmployeeStockPurchasePlan",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation": {
     "auth_ref": [
      "r26",
      "r27",
      "r233",
      "r265",
      "r285"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Value, after forfeiture, of shares issued under share-based payment arrangement. Excludes employee stock ownership plan (ESOP).",
        "label": "Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture",
        "terseLabel": "Stock-based compensation"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodValueShareBasedCompensation",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised": {
     "auth_ref": [
      "r52",
      "r228",
      "r233"
     ],
     "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": "Exercise of employee stock options"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodValueStockOptionsExercised",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockRepurchaseProgramAuthorizedAmount1": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of stock repurchase plan authorized.",
        "label": "Stock Repurchase Program, Authorized Amount",
        "terseLabel": "Stock Repurchase Program, Authorized Amount"
       }
      }
     },
     "localname": "StockRepurchaseProgramAuthorizedAmount1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShareholdersEquityNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount remaining of a stock repurchase plan authorized.",
        "label": "Stock Repurchase Program, Remaining Authorized Repurchase Amount",
        "terseLabel": "Stock Repurchase Program, Remaining Authorized Repurchase Amount"
       }
      }
     },
     "localname": "StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShareholdersEquityCommonStockRepurchasedandRetiredTableDetails",
      "http://www.f5.com/role/ShareholdersEquityNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockRepurchasedAndRetiredDuringPeriodShares": {
     "auth_ref": [
      "r26",
      "r27",
      "r228",
      "r233"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of shares that have been repurchased and retired during the period.",
        "label": "Stock Repurchased and Retired During Period, Shares",
        "negatedTerseLabel": "Repurchase of common stock, shares",
        "terseLabel": "Stock Repurchased and Retired During Period, Shares"
       }
      }
     },
     "localname": "StockRepurchasedAndRetiredDuringPeriodShares",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity",
      "http://www.f5.com/role/ShareholdersEquityCommonStockRepurchasedandRetiredTableDetails",
      "http://www.f5.com/role/ShareholdersEquityNarrativeDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockRepurchasedAndRetiredDuringPeriodValue": {
     "auth_ref": [
      "r26",
      "r27",
      "r228",
      "r233"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital).",
        "label": "Stock Repurchased and Retired During Period, Value",
        "negatedTerseLabel": "Repurchase of common stock"
       }
      }
     },
     "localname": "StockRepurchasedAndRetiredDuringPeriodValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Stockholders' Equity Attributable to Parent [Abstract]",
        "terseLabel": "Shareholders\u2019 equity"
       }
      }
     },
     "localname": "StockholdersEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest": {
     "auth_ref": [
      "r361",
      "r362",
      "r368"
     ],
     "calculation": {
      "http://www.f5.com/role/ConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.",
        "label": "Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest",
        "periodEndLabel": "Balance",
        "periodStartLabel": "Balance",
        "totalLabel": "Total shareholders\u2019 equity"
       }
      }
     },
     "localname": "StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedBalanceSheets",
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockholdersEquityNoteDisclosureTextBlock": {
     "auth_ref": [
      "r238"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.",
        "label": "Stockholders' Equity Note Disclosure [Text Block]",
        "terseLabel": "Stockholders' Equity"
       }
      }
     },
     "localname": "StockholdersEquityNoteDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShareholdersEquity"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SubleaseIncome": {
     "auth_ref": [
      "r408",
      "r415"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of sublease income excluding finance and operating lease expense.",
        "label": "Sublease Income",
        "terseLabel": "Sublease Income"
       }
      }
     },
     "localname": "SubleaseIncome",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_SubscriptionAndCirculationMember": {
     "auth_ref": [
      "r252"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Right to receive or access periodic material for specified period of time.",
        "label": "Subscription and Circulation [Member]",
        "terseLabel": "Subscription and Circulation [Member]"
       }
      }
     },
     "localname": "SubscriptionAndCirculationMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SubsequentEventMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Identifies event that occurred after the balance sheet date but before financial statements are issued or available to be issued.",
        "label": "Subsequent Event [Member]",
        "terseLabel": "Subsequent Event [Member]"
       }
      }
     },
     "localname": "SubsequentEventMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SubsequentEventTypeAxis": {
     "auth_ref": [
      "r418"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by event that occurred after the balance sheet date but before financial statements are issued or available to be issued.",
        "label": "Subsequent Event Type [Axis]",
        "terseLabel": "Subsequent Event Type [Axis]"
       }
      }
     },
     "localname": "SubsequentEventTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SubsequentEventTypeDomain": {
     "auth_ref": [
      "r418"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Event that occurred after the balance sheet date but before financial statements are issued or available to be issued.",
        "label": "Subsequent Event Type [Domain]",
        "terseLabel": "Subsequent Event Type [Domain]"
       }
      }
     },
     "localname": "SubsequentEventTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/StockBasedCompensationNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SupplementalBalanceSheetDisclosuresTextBlock": {
     "auth_ref": [
      "r60"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for supplemental balance sheet disclosures, including descriptions and amounts for assets, liabilities, and equity.",
        "label": "Supplemental Balance Sheet Disclosures [Text Block]",
        "verboseLabel": "Balance Sheet Details"
       }
      }
     },
     "localname": "SupplementalBalanceSheetDisclosuresTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetails"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SupplementalCashFlowInformationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Supplemental Cash Flow Information [Abstract]",
        "terseLabel": "Supplemental disclosures of cash flow information"
       }
      }
     },
     "localname": "SupplementalCashFlowInformationAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_TaxesPayableCurrent": {
     "auth_ref": [
      "r44"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsAccruedLiabilitiesDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_AccruedLiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Carrying value as of the balance sheet date of obligations incurred and payable for statutory income, sales, use, payroll, excise, real, property and other taxes. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
        "label": "Taxes Payable, Current",
        "terseLabel": "Income and other tax accruals"
       }
      }
     },
     "localname": "TaxesPayableCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsAccruedLiabilitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_TradeNamesMember": {
     "auth_ref": [
      "r353"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Rights acquired through registration of a business name to gain or protect exclusive use thereof.",
        "label": "Trade Names [Member]",
        "terseLabel": "Trade Names"
       }
      }
     },
     "localname": "TradeNamesMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsIntangibleAssetsDetails",
      "http://www.f5.com/role/BusinessCombinationsNarrativeDetails",
      "http://www.f5.com/role/BusinessCombinationsPurchasePriceAllocationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_TreasuryStockAcquiredAverageCostPerShare": {
     "auth_ref": [
      "r234"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Total cost of shares repurchased divided by the total number of shares repurchased.",
        "label": "Treasury Stock Acquired, Average Cost Per Share",
        "terseLabel": "Treasury Stock Acquired, Average Cost Per Share",
        "verboseLabel": "Treasury Stock Acquired, Average Cost Per Share"
       }
      }
     },
     "localname": "TreasuryStockAcquiredAverageCostPerShare",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ShareholdersEquityCommonStockRepurchasedandRetiredTableDetails",
      "http://www.f5.com/role/ShareholdersEquityNarrativeDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_TypeOfAdoptionMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Adoption and early adoption of sources of change to generally accepted accounting principles (GAAP) in the United States. The FASB released the FASB Accounting Standards Codification as the authoritative source of literature effective for interim and annual periods ending after September 15, 2009. As part of the Codification process, the FASB issues Accounting Standards Updates to amend the Codification but otherwise the Accounting Standards Updates are not authoritative in their own right. All previous accounting standards (such as FASB Statements of Financial Accounting Standards, FASB Interpretations, FASB Staff Positions, Emerging Issues Task Force Consensuses, other pronouncements of the FASB or other designated bodies, or other forms of GAAP are considered accounting pronouncements) were superseded upon the adoption of the Codification. For an interim period, references to the superseded standards are included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.",
        "label": "Type of Adoption [Domain]",
        "terseLabel": "Type of Adoption [Domain]"
       }
      }
     },
     "localname": "TypeOfAdoptionMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedStatementOfShareholdersEquity",
      "http://www.f5.com/role/LeasesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_USGovernmentAgenciesDebtSecuritiesMember": {
     "auth_ref": [
      "r259",
      "r434"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Debentures, notes, and other debt securities issued by US government agencies, for example, but not limited to, Government National Mortgage Association (GNMA or Ginnie Mae). Excludes US treasury securities and debt issued by government-sponsored Enterprises (GSEs), for example, but is not limited to, Federal Home Loan Mortgage Corporation (FHLMC or Freddie Mac), Federal National Mortgage Association (FNMA or Fannie Mae), and the Federal Home Loan Bank (FHLB).",
        "label": "US Government Agencies Debt Securities [Member]",
        "terseLabel": "US Government Agencies Debt Securities [Member]",
        "verboseLabel": "US Government Agencies Debt Securities [Member]"
       }
      }
     },
     "localname": "USGovernmentAgenciesDebtSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_USGovernmentDebtSecuritiesMember": {
     "auth_ref": [
      "r437"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Debt securities issued by the United States government.",
        "label": "US Government Debt Securities [Member]",
        "terseLabel": "US Government Debt Securities [Member]"
       }
      }
     },
     "localname": "USGovernmentDebtSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/FairValueMeasurementsScheduleOfFinancialAssetsMeasuredAtFairValueOnARecurringBasisDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfInvestmentsThatHaveBeenInAContinuousUnrealizedLossPositionDetails",
      "http://www.f5.com/role/ShortTermAndLongTermInvestmentsScheduleOfShortTermAndLongTermInvestmentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_UnbilledContractsReceivable": {
     "auth_ref": [
      "r53",
      "r422"
     ],
     "calculation": {
      "http://www.f5.com/role/BalanceSheetDetailsOtherCurrentAssetsDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_OtherAssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Unbilled amounts due for services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the entity and, at a minimum, one other party. An example would be amounts associated with contracts or programs where the recognized revenue for performance thereunder exceeds the amounts billed under the terms thereof as of the date of the balance sheet.",
        "label": "Unbilled Contracts Receivable",
        "terseLabel": "Capitalized contract acquisition costs"
       }
      }
     },
     "localname": "UnbilledContractsReceivable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/BalanceSheetDetailsOtherCurrentAssetsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecognizedTaxBenefits": {
     "auth_ref": [
      "r309",
      "r319"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of unrecognized tax benefits.",
        "label": "Unrecognized Tax Benefits",
        "periodEndLabel": "Balance, end of period",
        "periodStartLabel": "Balance, beginning of period",
        "terseLabel": "Unrecognized Tax Benefits"
       }
      }
     },
     "localname": "UnrecognizedTaxBenefits",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails",
      "http://www.f5.com/role/IncomeTaxesScheduleOfReconciliationOfBeginningAndEndingAmountOfUnrecognizedTaxBenefitsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions": {
     "auth_ref": [
      "r320"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.",
        "label": "Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions",
        "negatedTerseLabel": "Gross decreases related to prior period tax positions"
       }
      }
     },
     "localname": "UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfReconciliationOfBeginningAndEndingAmountOfUnrecognizedTaxBenefitsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities": {
     "auth_ref": [
      "r322"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.",
        "label": "Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities",
        "negatedLabel": "Decreases relating to settlements with tax authorities"
       }
      }
     },
     "localname": "UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfReconciliationOfBeginningAndEndingAmountOfUnrecognizedTaxBenefitsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued": {
     "auth_ref": [
      "r317"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.",
        "label": "Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued",
        "terseLabel": "Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued"
       }
      }
     },
     "localname": "UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions": {
     "auth_ref": [
      "r321"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.",
        "label": "Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions",
        "verboseLabel": "Gross increases related to current period tax positions"
       }
      }
     },
     "localname": "UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfReconciliationOfBeginningAndEndingAmountOfUnrecognizedTaxBenefitsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions": {
     "auth_ref": [
      "r320"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.",
        "label": "Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions",
        "verboseLabel": "Gross increases related to prior period tax positions"
       }
      }
     },
     "localname": "UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfReconciliationOfBeginningAndEndingAmountOfUnrecognizedTaxBenefitsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecognizedTaxBenefitsPeriodIncreaseDecrease": {
     "auth_ref": [
      "r319"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase (decrease) in unrecognized tax benefits attributable to uncertain tax positions taken in tax returns.",
        "label": "Unrecognized Tax Benefits, Period Increase (Decrease)",
        "terseLabel": "Unrecognized Tax Benefits, Period Increase (Decrease)"
       }
      }
     },
     "localname": "UnrecognizedTaxBenefitsPeriodIncreaseDecrease",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations": {
     "auth_ref": [
      "r323"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.",
        "label": "Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations",
        "negatedLabel": "Reductions due to lapses of statute of limitations"
       }
      }
     },
     "localname": "UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesScheduleOfReconciliationOfBeginningAndEndingAmountOfUnrecognizedTaxBenefitsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate": {
     "auth_ref": [
      "r324"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.",
        "label": "Unrecognized Tax Benefits that Would Impact Effective Tax Rate",
        "terseLabel": "Unrecognized Tax Benefits that Would Impact Effective Tax Rate"
       }
      }
     },
     "localname": "UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_UseOfEstimates": {
     "auth_ref": [
      "r143",
      "r144",
      "r146",
      "r147",
      "r151",
      "r152",
      "r153"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for the use of estimates in the preparation of financial statements in conformity with generally accepted accounting principles.",
        "label": "Use of Estimates, Policy [Policy Text Block]",
        "verboseLabel": "Use Of Estimates and Assumptions"
       }
      }
     },
     "localname": "UseOfEstimates",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesPolicy"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount": {
     "auth_ref": [
      "r310"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset.",
        "label": "Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount",
        "terseLabel": "Valuation Allowance, Deferred Tax Asset, Change in Amount"
       }
      }
     },
     "localname": "ValuationAllowanceDeferredTaxAssetChangeInAmount",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/IncomeTaxesNarrativeDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_VariableLeaseCost": {
     "auth_ref": [
      "r407",
      "r415"
     ],
     "calculation": {
      "http://www.f5.com/role/LeasesOperatingLeaseExpenseDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_LeaseCost",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.",
        "label": "Variable Lease, Cost",
        "terseLabel": "Variable lease expense"
       }
      }
     },
     "localname": "VariableLeaseCost",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/LeasesOperatingLeaseExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_VariableRateAxis": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by type of variable rate.",
        "label": "Variable Rate [Axis]",
        "terseLabel": "Variable Rate [Axis]"
       }
      }
     },
     "localname": "VariableRateAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_VariableRateDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Interest rate that fluctuates over time as a result of an underlying benchmark interest rate or index.",
        "label": "Variable Rate [Domain]",
        "terseLabel": "Variable Rate [Domain]"
       }
      }
     },
     "localname": "VariableRateDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/DebtFacilitiesNarrativeDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment": {
     "auth_ref": [
      "r136"
     ],
     "calculation": {
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfComputationOfBasicAndDilutedNetIncomePerShareDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding",
       "weight": 1.0
      }
     },
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation.",
        "label": "Weighted Average Number Diluted Shares Outstanding Adjustment",
        "terseLabel": "Dilutive effect of common shares from stock options and restricted stock units",
        "verboseLabel": "Weighted Average Number Diluted Shares Outstanding Adjustment"
       }
      }
     },
     "localname": "WeightedAverageNumberDilutedSharesOutstandingAdjustment",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/NetIncomePerShareDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfComputationOfBasicAndDilutedNetIncomePerShareDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding": {
     "auth_ref": [
      "r132",
      "r136"
     ],
     "calculation": {
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfComputationOfBasicAndDilutedNetIncomePerShareDetails": {
       "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",
        "terseLabel": "Weighted Average Number of Shares Outstanding, Diluted",
        "totalLabel": "Weighted average shares outstanding - diluted",
        "verboseLabel": "Weighted average shares - diluted (shares)"
       }
      }
     },
     "localname": "WeightedAverageNumberOfDilutedSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/NetIncomePerShareDetails",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfComputationOfBasicAndDilutedNetIncomePerShareDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_WeightedAverageNumberOfSharesOutstandingBasic": {
     "auth_ref": [
      "r131",
      "r136"
     ],
     "calculation": {
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfComputationOfBasicAndDilutedNetIncomePerShareDetails": {
       "order": 2.0,
       "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": "Weighted average shares - basic (shares)",
        "verboseLabel": "Weighted average shares outstanding - basic"
       }
      }
     },
     "localname": "WeightedAverageNumberOfSharesOutstandingBasic",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.f5.com/role/ConsolidatedIncomeStatements",
      "http://www.f5.com/role/NetIncomePerShareDetails",
      "http://www.f5.com/role/QuarterlyResultsOfOperationsUnauditedScheduleOfQuarterlyResultsOfOperationsDetails",
      "http://www.f5.com/role/SummaryOfSignificantAccountingPoliciesScheduleOfComputationOfBasicAndDilutedNetIncomePerShareDetails"
     ],
     "xbrltype": "sharesItemType"
    }
   },
   "unitCount": 9
  }
 },
 "std_ref": {
  "r0": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=6359566&loc=d3e326-107755"
  },
  "r1": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765"
  },
  "r10": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6935-107765"
  },
  "r100": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585"
  },
  "r101": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585"
  },
  "r102": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3367-108585"
  },
  "r103": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3367-108585"
  },
  "r104": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "24",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3521-108585"
  },
  "r105": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3536-108585"
  },
  "r106": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3536-108585"
  },
  "r107": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585"
  },
  "r108": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585"
  },
  "r109": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585"
  },
  "r11": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e7018-107765"
  },
  "r110": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3044-108585"
  },
  "r111": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=98513485&loc=d3e4273-108586"
  },
  "r112": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=98513485&loc=d3e4297-108586"
  },
  "r113": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586"
  },
  "r114": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=98513485&loc=d3e4313-108586"
  },
  "r115": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586"
  },
  "r116": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=98513485&loc=SL98516268-108586"
  },
  "r117": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=84158767&loc=d3e18726-107790"
  },
  "r118": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=84158767&loc=d3e18780-107790"
  },
  "r119": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=84158767&loc=d3e18823-107790"
  },
  "r12": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6361739&loc=d3e7789-107766"
  },
  "r120": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=84158767&loc=d3e18823-107790"
  },
  "r121": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(h)(1))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690"
  },
  "r122": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(h)(2))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690"
  },
  "r123": {
   "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=26873400&loc=d3e23780-122690"
  },
  "r124": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08.(e),(f))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690"
  },
  "r125": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08.(h)(1)(i))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690"
  },
  "r126": {
   "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=26873400&loc=d3e23780-122690"
  },
  "r127": {
   "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=26873400&loc=d3e24072-122690"
  },
  "r128": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "235",
   "URI": "http://asc.fasb.org/topic&trid=2122369"
  },
  "r129": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794"
  },
  "r13": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 201.5-02(24))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r130": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794"
  },
  "r131": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e1448-109256"
  },
  "r132": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e1505-109256"
  },
  "r133": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e1252-109256"
  },
  "r134": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "60B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=SL5780133-109256"
  },
  "r135": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&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=6371337&loc=d3e3550-109257"
  },
  "r137": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257"
  },
  "r138": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "52",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117327953&loc=d3e4984-109258"
  },
  "r139": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "260",
   "URI": "http://asc.fasb.org/topic&trid=2144383"
  },
  "r14": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 201.5-02(25))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r140": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "270",
   "URI": "http://asc.fasb.org/extlink&oid=116846552&loc=d3e543-108305"
  },
  "r141": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "270",
   "URI": "http://asc.fasb.org/extlink&oid=118952077&loc=d3e1280-108306"
  },
  "r142": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "270",
   "URI": "http://asc.fasb.org/topic&trid=2126967"
  },
  "r143": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "275",
   "URI": "http://asc.fasb.org/extlink&oid=99393423&loc=d3e5967-108592"
  },
  "r144": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "275",
   "URI": "http://asc.fasb.org/extlink&oid=99393423&loc=d3e5967-108592"
  },
  "r145": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "275",
   "URI": "http://asc.fasb.org/extlink&oid=99393423&loc=d3e5967-108592"
  },
  "r146": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "275",
   "URI": "http://asc.fasb.org/extlink&oid=99393423&loc=d3e6161-108592"
  },
  "r147": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "275",
   "URI": "http://asc.fasb.org/extlink&oid=99393423&loc=d3e6191-108592"
  },
  "r148": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "18",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "275",
   "URI": "http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592"
  },
  "r149": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "18",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "275",
   "URI": "http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592"
  },
  "r15": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 201.5-02(26))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r150": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "275",
   "URI": "http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592"
  },
  "r151": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "275",
   "URI": "http://asc.fasb.org/extlink&oid=99393423&loc=d3e6061-108592"
  },
  "r152": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "275",
   "URI": "http://asc.fasb.org/extlink&oid=99393423&loc=d3e6132-108592"
  },
  "r153": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "275",
   "URI": "http://asc.fasb.org/extlink&oid=99393423&loc=d3e6143-108592"
  },
  "r154": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8721-108599"
  },
  "r155": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599"
  },
  "r156": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&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=115929826&loc=d3e8736-108599"
  },
  "r158": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599"
  },
  "r159": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8813-108599"
  },
  "r16": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r160": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "30",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8906-108599"
  },
  "r161": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "40",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e9031-108599"
  },
  "r162": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "41",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e9038-108599"
  },
  "r163": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "41",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "b",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e9038-108599"
  },
  "r164": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "41",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e9038-108599"
  },
  "r165": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "42",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e9054-108599"
  },
  "r166": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "280",
   "URI": "http://asc.fasb.org/topic&trid=2134510"
  },
  "r167": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=118952595&loc=d3e4428-111522"
  },
  "r168": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=118952595&loc=d3e4531-111522"
  },
  "r169": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=118936363&loc=d3e5074-111524"
  },
  "r17": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r170": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=118954083&loc=d3e26853-111562"
  },
  "r171": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563"
  },
  "r172": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=118939692&loc=d3e27290-111563"
  },
  "r173": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=118939692&loc=d3e27337-111563"
  },
  "r174": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=118939692&loc=d3e27357-111563"
  },
  "r175": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "320",
   "URI": "http://asc.fasb.org/topic&trid=2196928"
  },
  "r176": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(2)",
   "Topic": "323",
   "URI": "http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571"
  },
  "r177": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=118955202&loc=SL82895884-210446"
  },
  "r178": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "35",
   "SubTopic": "10",
   "Topic": "330",
   "URI": "http://asc.fasb.org/extlink&oid=116846819&loc=d3e3927-108312"
  },
  "r179": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "330",
   "URI": "http://asc.fasb.org/extlink&oid=116847112&loc=d3e4492-108314"
  },
  "r18": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r180": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "330",
   "URI": "http://asc.fasb.org/extlink&oid=116847112&loc=d3e4556-108314"
  },
  "r181": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "05",
   "SubTopic": "10",
   "Topic": "340",
   "URI": "http://asc.fasb.org/extlink&oid=68074540&loc=d3e5879-108316"
  },
  "r182": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "40",
   "Subparagraph": "(b)",
   "Topic": "340",
   "URI": "http://asc.fasb.org/extlink&oid=68051541&loc=SL49131251-203054"
  },
  "r183": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "40",
   "Subparagraph": "(a)",
   "Topic": "340",
   "URI": "http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054"
  },
  "r184": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "40",
   "Subparagraph": "(b)",
   "Topic": "340",
   "URI": "http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054"
  },
  "r185": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "40",
   "Topic": "340",
   "URI": "http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054"
  },
  "r186": {
   "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"
  },
  "r187": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975"
  },
  "r188": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267"
  },
  "r189": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267"
  },
  "r19": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(2))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r190": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267"
  },
  "r191": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=108376223&loc=d3e13854-109267"
  },
  "r192": {
   "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"
  },
  "r193": {
   "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"
  },
  "r194": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)(3)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275"
  },
  "r195": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(d)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275"
  },
  "r196": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275"
  },
  "r197": {
   "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"
  },
  "r198": {
   "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"
  },
  "r199": {
   "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"
  },
  "r2": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765"
  },
  "r20": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(22))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r200": {
   "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"
  },
  "r201": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(d)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275"
  },
  "r202": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "30",
   "SubTopic": "40",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=118172244&loc=d3e17916-109280"
  },
  "r203": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "50",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=16397303&loc=d3e19379-109286"
  },
  "r204": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "05",
   "SubTopic": "10",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=109226317&loc=d3e202-110218"
  },
  "r205": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=109226348&loc=d3e2420-110228"
  },
  "r206": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229"
  },
  "r207": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229"
  },
  "r208": {
   "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"
  },
  "r209": {
   "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"
  },
  "r21": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(23))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r210": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 5.CC)",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=27011434&loc=d3e125687-122742"
  },
  "r211": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "420",
   "URI": "http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869"
  },
  "r212": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(2)",
   "Topic": "420",
   "URI": "http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869"
  },
  "r213": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "420",
   "URI": "http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869"
  },
  "r214": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB TOPIC 5.P.3)",
   "Topic": "420",
   "URI": "http://asc.fasb.org/extlink&oid=115931487&loc=d3e140864-122747"
  },
  "r215": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 5.P.3)",
   "Topic": "420",
   "URI": "http://asc.fasb.org/extlink&oid=115931487&loc=d3e140864-122747"
  },
  "r216": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB TOPIC 5.P.4(b)(2))",
   "Topic": "420",
   "URI": "http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747"
  },
  "r217": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB TOPIC 5.P.4(b))",
   "Topic": "420",
   "URI": "http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747"
  },
  "r218": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB TOPIC 5.P.4)",
   "Topic": "420",
   "URI": "http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747"
  },
  "r219": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 5.P.4(b))",
   "Topic": "420",
   "URI": "http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747"
  },
  "r22": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(24))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r220": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "420",
   "URI": "http://asc.fasb.org/topic&trid=2175745"
  },
  "r221": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "440",
   "URI": "http://asc.fasb.org/topic&trid=2144648"
  },
  "r222": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=118942415&loc=d3e14326-108349"
  },
  "r223": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "450",
   "URI": "http://asc.fasb.org/topic&trid=2127136"
  },
  "r224": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "460",
   "URI": "http://asc.fasb.org/extlink&oid=68068213&loc=d3e12565-110249"
  },
  "r225": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601"
  },
  "r226": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(3)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870"
  },
  "r227": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "470",
   "URI": "http://asc.fasb.org/topic&trid=2208564"
  },
  "r228": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644"
  },
  "r229": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644"
  },
  "r23": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r230": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21506-112644"
  },
  "r231": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21521-112644"
  },
  "r232": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21538-112644"
  },
  "r233": {
   "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=27012166&loc=d3e187085-122770"
  },
  "r234": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655"
  },
  "r235": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=6405834&loc=d3e23285-112656"
  },
  "r236": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=6405834&loc=d3e23309-112656"
  },
  "r237": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=6405834&loc=d3e23315-112656"
  },
  "r238": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "505",
   "URI": "http://asc.fasb.org/topic&trid=2208762"
  },
  "r239": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118944033&loc=SL49130531-203044"
  },
  "r24": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(26)(a))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r240": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118944033&loc=SL49130532-203044"
  },
  "r241": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118944033&loc=SL49130533-203044"
  },
  "r242": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130551-203045"
  },
  "r243": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130551-203045"
  },
  "r244": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130551-203045"
  },
  "r245": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130551-203045"
  },
  "r246": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130556-203045"
  },
  "r247": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(1)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130556-203045"
  },
  "r248": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045"
  },
  "r249": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045"
  },
  "r25": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(26)(b))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r250": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130549-203045"
  },
  "r251": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130549-203045"
  },
  "r252": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "91",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118944142&loc=SL49130690-203046-203046"
  },
  "r253": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "91",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118944142&loc=SL49130690-203046-203046"
  },
  "r254": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "91",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118944142&loc=SL49130690-203046-203046"
  },
  "r255": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=113356391&loc=SL49131195-203048"
  },
  "r256": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "606",
   "URI": "http://asc.fasb.org/topic&trid=49130388"
  },
  "r257": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "710",
   "URI": "http://asc.fasb.org/topic&trid=2127225"
  },
  "r258": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "712",
   "URI": "http://asc.fasb.org/topic&trid=2197446"
  },
  "r259": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(ii)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r26": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r260": {
   "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=118255775&loc=d3e1928-114920"
  },
  "r261": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118257860&loc=d3e4179-114921"
  },
  "r262": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "715",
   "URI": "http://asc.fasb.org/topic&trid=2235017"
  },
  "r263": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901"
  },
  "r264": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901"
  },
  "r265": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901"
  },
  "r266": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901"
  },
  "r267": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r268": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(3)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r269": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a),(g)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r27": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r270": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b),(f)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r271": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r272": {
   "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=116856206&loc=d3e5070-113901"
  },
  "r273": {
   "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=116856206&loc=d3e5070-113901"
  },
  "r274": {
   "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=116856206&loc=d3e5070-113901"
  },
  "r275": {
   "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=116856206&loc=d3e5070-113901"
  },
  "r276": {
   "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=116856206&loc=d3e5070-113901"
  },
  "r277": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(iv)(3)-(4)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r278": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r279": {
   "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=116856206&loc=d3e5070-113901"
  },
  "r28": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r280": {
   "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=116856206&loc=d3e5070-113901"
  },
  "r281": {
   "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=116856206&loc=d3e5070-113901"
  },
  "r282": {
   "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=116856206&loc=d3e5070-113901"
  },
  "r283": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(iii)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r284": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r285": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r286": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r287": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r288": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r289": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r29": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r290": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r291": {
   "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=116856206&loc=d3e5070-113901"
  },
  "r292": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)(2)(ii)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r293": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)(2)(iii)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r294": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)(2)(iv)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r295": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(g)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r296": {
   "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=116856206&loc=d3e5070-113901"
  },
  "r297": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(i)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r298": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r299": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=SL79508275-113901"
  },
  "r3": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765"
  },
  "r30": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r300": {
   "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=115993241&loc=d3e301413-122809"
  },
  "r301": {
   "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=115993241&loc=d3e301413-122809"
  },
  "r302": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "718",
   "URI": "http://asc.fasb.org/topic&trid=2228938"
  },
  "r303": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "35",
   "Subparagraph": "(a)",
   "Topic": "720",
   "URI": "http://asc.fasb.org/extlink&oid=6420018&loc=d3e36677-107848"
  },
  "r304": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "35",
   "Subparagraph": "(b)",
   "Topic": "720",
   "URI": "http://asc.fasb.org/extlink&oid=6420018&loc=d3e36677-107848"
  },
  "r305": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "730",
   "URI": "http://asc.fasb.org/extlink&oid=6420194&loc=d3e21568-108373"
  },
  "r306": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=117330534&loc=d3e28680-109314"
  },
  "r307": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=117330534&loc=d3e28680-109314"
  },
  "r308": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=117330534&loc=d3e28680-109314"
  },
  "r309": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=116821951&loc=SL37586934-109318"
  },
  "r31": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(4)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r310": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=116821951&loc=d3e32123-109318"
  },
  "r311": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=116821951&loc=d3e32247-109318"
  },
  "r312": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=116821951&loc=d3e32280-109318"
  },
  "r313": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=116821951&loc=d3e31917-109318"
  },
  "r314": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=116821951&loc=d3e31931-109318"
  },
  "r315": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319"
  },
  "r316": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319"
  },
  "r317": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319"
  },
  "r318": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319"
  },
  "r319": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319"
  },
  "r32": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(6)(a))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r320": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319"
  },
  "r321": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(2)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319"
  },
  "r322": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(3)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319"
  },
  "r323": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(4)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319"
  },
  "r324": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319"
  },
  "r325": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32809-109319"
  },
  "r326": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "19",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32840-109319"
  },
  "r327": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319"
  },
  "r328": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319"
  },
  "r329": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b),(c)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319"
  },
  "r33": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(6)(b))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r330": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319"
  },
  "r331": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319"
  },
  "r332": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32847-109319"
  },
  "r333": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319"
  },
  "r334": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319"
  },
  "r335": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32621-109319"
  },
  "r336": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32632-109319"
  },
  "r337": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319"
  },
  "r338": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319"
  },
  "r339": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319"
  },
  "r34": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(6)(c))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r340": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB TOPIC 6.I)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=116825942&loc=d3e330036-122817"
  },
  "r341": {
   "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=116825942&loc=d3e330036-122817"
  },
  "r342": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 11.C)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=116825942&loc=d3e330215-122817"
  },
  "r343": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=109238882&loc=d3e38679-109324"
  },
  "r344": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "05",
   "SubTopic": "30",
   "Topic": "740",
   "URI": "http://asc.fasb.org/extlink&oid=65884525&loc=d3e40913-109327"
  },
  "r345": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "740",
   "URI": "http://asc.fasb.org/topic&trid=2144680"
  },
  "r346": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "05",
   "SubTopic": "10",
   "Subparagraph": "(a)-(d)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=6909625&loc=d3e227-128457"
  },
  "r347": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "23",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "10",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=116868678&loc=d3e1043-128460"
  },
  "r348": {
   "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"
  },
  "r349": {
   "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"
  },
  "r35": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r350": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "37",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=116868840&loc=d3e2207-128464"
  },
  "r351": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=116869197&loc=d3e4845-128472"
  },
  "r352": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=116869197&loc=d3e4845-128472"
  },
  "r353": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=77890550&loc=d3e5263-128473"
  },
  "r354": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Subparagraph": "(e)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=77890550&loc=d3e5263-128473"
  },
  "r355": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=77890550&loc=d3e5333-128473"
  },
  "r356": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "38",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=77890550&loc=d3e5504-128473"
  },
  "r357": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "44",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=77890550&loc=d3e5558-128473"
  },
  "r358": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(b)(1)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479"
  },
  "r359": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(d)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479"
  },
  "r36": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.12)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r360": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "805",
   "URI": "http://asc.fasb.org/topic&trid=2303972"
  },
  "r361": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=108774443&loc=SL4568447-111683"
  },
  "r362": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=108774443&loc=SL4568740-111683"
  },
  "r363": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "19",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=108774443&loc=SL4569616-111683"
  },
  "r364": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=108774443&loc=SL4569643-111683"
  },
  "r365": {
   "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"
  },
  "r366": {
   "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"
  },
  "r367": {
   "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"
  },
  "r368": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4I",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116874947&loc=SL4590271-111686"
  },
  "r369": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4K",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116874947&loc=SL4591552-111686"
  },
  "r37": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.13(a))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r370": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.3A-02)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116822174&loc=d3e355033-122828"
  },
  "r371": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.3A-03)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116822174&loc=d3e355100-122828"
  },
  "r372": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258"
  },
  "r373": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258"
  },
  "r374": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bb)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258"
  },
  "r375": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bbb)(1)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258"
  },
  "r376": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bbb)(2)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258"
  },
  "r377": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258"
  },
  "r378": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258"
  },
  "r379": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=d3e19279-110258"
  },
  "r38": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r380": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=SL6742756-110258"
  },
  "r381": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=SL6742756-110258"
  },
  "r382": {
   "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"
  },
  "r383": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=118260190&loc=d3e13279-108611"
  },
  "r384": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=118260190&loc=d3e13531-108611"
  },
  "r385": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=118260190&loc=d3e13537-108611"
  },
  "r386": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=6450222&loc=d3e30840-110895"
  },
  "r387": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "230",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=98513438&loc=d3e33268-110906"
  },
  "r388": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Subparagraph": "(b,c)",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900"
  },
  "r389": {
   "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"
  },
  "r39": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r390": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399"
  },
  "r391": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399"
  },
  "r392": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399"
  },
  "r393": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "30",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400"
  },
  "r394": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "40",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(Note 3)",
   "Topic": "840",
   "URI": "http://asc.fasb.org/extlink&oid=82846649&loc=d3e38371-112697"
  },
  "r395": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "840",
   "URI": "http://asc.fasb.org/extlink&oid=77902458&loc=d3e39927-112707"
  },
  "r396": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "840",
   "URI": "http://asc.fasb.org/extlink&oid=77902758&loc=d3e41502-112717"
  },
  "r397": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "840",
   "URI": "http://asc.fasb.org/extlink&oid=77902758&loc=d3e41502-112717"
  },
  "r398": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "840",
   "URI": "http://asc.fasb.org/extlink&oid=84164653&loc=d3e41551-112718"
  },
  "r399": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=119364159&loc=SL77916155-209984"
  },
  "r4": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(g)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765"
  },
  "r40": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r400": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888369&loc=SL77918431-209957"
  },
  "r401": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977"
  },
  "r402": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977"
  },
  "r403": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888419&loc=SL77918643-209977"
  },
  "r404": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980"
  },
  "r405": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r406": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r407": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r408": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(e)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r409": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(1)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r41": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.19(a))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r410": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(2)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r411": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(3)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r412": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(4)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r413": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r414": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918701-209980"
  },
  "r415": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "53",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888399&loc=SL77918982-209971"
  },
  "r416": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/subtopic&trid=77888251"
  },
  "r417": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=119202524&loc=SL77919396-209981"
  },
  "r418": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "855",
   "URI": "http://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662"
  },
  "r419": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=118948506&loc=d3e107207-111719"
  },
  "r42": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.19(b),22(b))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r420": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=118948506&loc=d3e107207-111719"
  },
  "r421": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=118948506&loc=d3e107207-111719"
  },
  "r422": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "310",
   "Topic": "912",
   "URI": "http://asc.fasb.org/extlink&oid=118261985&loc=d3e55302-109406"
  },
  "r423": {
   "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"
  },
  "r424": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "320",
   "Topic": "940",
   "URI": "http://asc.fasb.org/subtopic&trid=2176304"
  },
  "r425": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(1)(a))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
  },
  "r426": {
   "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=6876686&loc=d3e534808-122878"
  },
  "r427": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(15)(1))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
  },
  "r428": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(15)(2))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
  },
  "r429": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(16))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
  },
  "r43": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.19)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r430": {
   "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=6876686&loc=d3e534808-122878"
  },
  "r431": {
   "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=6876686&loc=d3e534808-122878"
  },
  "r432": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(4))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
  },
  "r433": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(5))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
  },
  "r434": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(6)(a)(1))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
  },
  "r435": {
   "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=6876686&loc=d3e534808-122878"
  },
  "r436": {
   "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=6876686&loc=d3e534808-122878"
  },
  "r437": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.6(a)(1))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
  },
  "r438": {
   "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=116637391&loc=SL114874048-224260"
  },
  "r439": {
   "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=116637391&loc=SL114874048-224260"
  },
  "r44": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.19,20)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r440": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "320",
   "Topic": "942",
   "URI": "http://asc.fasb.org/subtopic&trid=2209399"
  },
  "r441": {
   "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"
  },
  "r442": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "470",
   "Subparagraph": "e",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823"
  },
  "r443": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "470",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823"
  },
  "r444": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "825",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=108315417&loc=d3e61044-112788"
  },
  "r445": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(15)(b)(2))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910"
  },
  "r446": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(16))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910"
  },
  "r447": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(1)(g))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910"
  },
  "r448": {
   "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=119400593&loc=d3e572229-122910"
  },
  "r449": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(15)(b)(1))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910"
  },
  "r45": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r450": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(16))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910"
  },
  "r451": {
   "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=119400593&loc=d3e572229-122910"
  },
  "r452": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(2))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910"
  },
  "r453": {
   "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=119400593&loc=d3e572229-122910"
  },
  "r454": {
   "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=119400593&loc=d3e572229-122910"
  },
  "r455": {
   "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=119400593&loc=d3e572229-122910"
  },
  "r456": {
   "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=119400593&loc=d3e572229-122910"
  },
  "r457": {
   "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=116637232&loc=SL114874131-224263"
  },
  "r458": {
   "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=116637232&loc=SL114874131-224263"
  },
  "r459": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04.2)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=116637232&loc=SL114874131-224263"
  },
  "r46": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.21)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r460": {
   "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"
  },
  "r461": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13H",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "40",
   "Subparagraph": "(a)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=117419784&loc=SL117783719-158441"
  },
  "r462": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13H",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "40",
   "Subparagraph": "(b)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=117419784&loc=SL117783719-158441"
  },
  "r463": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13H",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "40",
   "Subparagraph": "(c)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=117419784&loc=SL117783719-158441"
  },
  "r464": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(e)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=117420044&loc=d3e19393-158473"
  },
  "r465": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "80",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=118959010&loc=SL117422397-158474"
  },
  "r466": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "825",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=99380617&loc=SL75241803-196195"
  },
  "r467": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-12(2)(i))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611133-123010"
  },
  "r468": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-12C(1)(a))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611225-123010"
  },
  "r469": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-13(1))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611282-123010"
  },
  "r47": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.22)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r470": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-15(Column A))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611379-123010"
  },
  "r471": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "320",
   "Topic": "946",
   "URI": "http://asc.fasb.org/subtopic&trid=2324412"
  },
  "r472": {
   "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=6589523&loc=d3e617274-123014"
  },
  "r473": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "740",
   "Topic": "954",
   "URI": "http://asc.fasb.org/extlink&oid=6491622&loc=d3e9504-115650"
  },
  "r474": {
   "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=6590653&loc=d3e638233-123024"
  },
  "r475": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(2)",
   "Topic": "985",
   "URI": "http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756"
  },
  "r476": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "985",
   "URI": "http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756"
  },
  "r477": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "985",
   "URI": "http://asc.fasb.org/extlink&oid=6501960&loc=d3e128487-111756"
  },
  "r478": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b"
  },
  "r479": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b-23"
  },
  "r48": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.24)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r480": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "d1-1"
  },
  "r481": {
   "Name": "Forms 10-K, 10-Q, 20-F",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "13",
   "Subsection": "a-1-"
  },
  "r482": {
   "Name": "Forms 10-K, 20-F, 40-F",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "15",
   "Subsection": "d-1"
  },
  "r483": {
   "Name": "Regulation 12B",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b-2"
  },
  "r484": {
   "Name": "Regulation S-T",
   "Number": "232",
   "Publisher": "SEC",
   "Section": "405"
  },
  "r49": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r5": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765"
  },
  "r50": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.26(c))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r51": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r52": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r53": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.3(c)(3))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r54": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.6(a)(1))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r55": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.6(a)(4))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r56": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.6(a))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r57": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.6(b))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r58": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r59": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.9)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r6": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6787-107765"
  },
  "r60": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "210",
   "URI": "http://asc.fasb.org/topic&trid=2122208"
  },
  "r61": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580"
  },
  "r62": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580"
  },
  "r63": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580"
  },
  "r64": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580"
  },
  "r65": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e637-108580"
  },
  "r66": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e640-108580"
  },
  "r67": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e681-108580"
  },
  "r68": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669686-108580"
  },
  "r69": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e689-108580"
  },
  "r7": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6801-107765"
  },
  "r70": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL34724391-108580"
  },
  "r71": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL34724394-108580"
  },
  "r72": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669619-108580"
  },
  "r73": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669619-108580"
  },
  "r74": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669619-108580"
  },
  "r75": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669625-108580"
  },
  "r76": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669625-108580"
  },
  "r77": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116657188&loc=SL116659661-227067"
  },
  "r78": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118951672&loc=d3e1436-108581"
  },
  "r79": {
   "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=116634182&loc=SL114868664-224227"
  },
  "r8": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6812-107765"
  },
  "r80": {
   "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=116634182&loc=SL114868664-224227"
  },
  "r81": {
   "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=116634182&loc=SL114868664-224227"
  },
  "r82": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.1)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r83": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.1,2)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r84": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.2(a),(d))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r85": {
   "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=116634182&loc=SL114868664-224227"
  },
  "r86": {
   "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=116634182&loc=SL114868664-224227"
  },
  "r87": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.7(b))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r88": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.8)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r89": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.9)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r9": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6911-107765"
  },
  "r90": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3151-108585"
  },
  "r91": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3179-108585"
  },
  "r92": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a),(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3179-108585"
  },
  "r93": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3179-108585"
  },
  "r94": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585"
  },
  "r95": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585"
  },
  "r96": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585"
  },
  "r97": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3255-108585"
  },
  "r98": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3255-108585"
  },
  "r99": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585"
  }
 },
 "version": "2.1"
}
