{
 "instance": {
  "d194083d10q.htm": {
   "axisCustom": 0,
   "axisStandard": 21,
   "contextCount": 170,
   "dts": {
    "calculationLink": {
     "local": [
      "gbt-20210630_cal.xml"
     ]
    },
    "definitionLink": {
     "local": [
      "gbt-20210630_def.xml"
     ],
     "remote": [
      "http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-eedm-def-2020-01-31.xml",
      "http://xbrl.fasb.org/srt/2020/elts/srt-eedm1-def-2020-01-31.xml"
     ]
    },
    "inline": {
     "local": [
      "d194083d10q.htm"
     ]
    },
    "labelLink": {
     "local": [
      "gbt-20210630_lab.xml"
     ],
     "remote": [
      "http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-doc-2020-01-31.xml",
      "https://xbrl.sec.gov/dei/2020/dei-doc-2020-01-31.xml"
     ]
    },
    "presentationLink": {
     "local": [
      "gbt-20210630_pre.xml"
     ]
    },
    "referenceLink": {
     "remote": [
      "https://xbrl.sec.gov/dei/2020/dei-ref-2020-01-31.xml",
      "http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-ref-2020-01-31.xml"
     ]
    },
    "schema": {
     "local": [
      "gbt-20210630.xsd"
     ],
     "remote": [
      "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",
      "https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd",
      "http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd",
      "http://www.xbrl.org/2005/xbrldt-2005.xsd",
      "http://www.xbrl.org/dtr/type/nonNumeric-2009-12-16.xsd",
      "http://www.xbrl.org/dtr/type/numeric-2009-12-16.xsd",
      "http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd",
      "http://xbrl.fasb.org/us-gaap/2020/elts/us-roles-2020-01-31.xsd",
      "http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd",
      "http://www.xbrl.org/2006/ref-2006-02-27.xsd",
      "http://xbrl.fasb.org/srt/2020/elts/srt-types-2020-01-31.xsd",
      "http://xbrl.fasb.org/srt/2020/elts/srt-roles-2020-01-31.xsd",
      "https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd",
      "http://xbrl.fasb.org/us-gaap/2020/elts/us-types-2020-01-31.xsd",
      "http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd",
      "http://www.xbrl.org/lrr/role/net-2009-12-16.xsd",
      "https://xbrl.sec.gov/currency/2020/currency-2020-01-31.xsd",
      "https://xbrl.sec.gov/exch/2020/exch-2020-01-31.xsd",
      "https://xbrl.sec.gov/naics/2017/naics-2017-01-31.xsd",
      "https://xbrl.sec.gov/sic/2020/sic-2020-01-31.xsd",
      "https://xbrl.sec.gov/stpr/2018/stpr-2018-01-31.xsd",
      "http://www.xbrl.org/lrr/arcrole/factExplanatory-2009-12-16.xsd",
      "http://www.xbrl.org/lrr/role/deprecated-2009-12-16.xsd",
      "http://www.xbrl.org/lrr/role/reference-2009-12-16.xsd",
      "http://xbrl.fasb.org/us-gaap/2020/elts/us-parts-codification-2020-01-31.xsd"
     ]
    }
   },
   "elementCount": 425,
   "entityCount": 1,
   "hidden": {
    "http://xbrl.sec.gov/dei/2020-01-31": 5,
    "total": 5
   },
   "keyCustom": 39,
   "keyStandard": 293,
   "memberCustom": 8,
   "memberStandard": 31,
   "nsprefix": "gbt",
   "nsuri": "http://www.gbt.com/20210630",
   "report": {
    "R1": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "div",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:DocumentType",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "document",
     "isDefault": "true",
     "longName": "1001 - Document - Cover Page",
     "role": "http://www.gbt.com/role/CoverPage",
     "shortName": "Cover Page",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "div",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:DocumentType",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R10": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1010 - Disclosure - Available-for-Sale Securities",
     "role": "http://www.gbt.com/role/AvailableForSaleSecurities",
     "shortName": "Available-for-Sale Securities",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R11": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SupplementalBalanceSheetDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1011 - Disclosure - Balance Sheet Components",
     "role": "http://www.gbt.com/role/BalanceSheetComponents",
     "shortName": "Balance Sheet Components",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SupplementalBalanceSheetDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R12": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DebtDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1012 - Disclosure - Long-term Debt",
     "role": "http://www.gbt.com/role/LongTermDebt",
     "shortName": "Long-term Debt",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DebtDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R13": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1013 - Disclosure - Commitments and Contingencies",
     "role": "http://www.gbt.com/role/CommitmentsAndContingencies",
     "shortName": "Commitments and Contingencies",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommitmentsAndContingenciesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R14": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1014 - Disclosure - Stock-Based Compensation",
     "role": "http://www.gbt.com/role/StockBasedCompensation",
     "shortName": "Stock-Based Compensation",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R15": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EarningsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1015 - Disclosure - Net Loss per Share",
     "role": "http://www.gbt.com/role/NetLossPerShare",
     "shortName": "Net Loss per Share",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EarningsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R16": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:SignificantAccountingPoliciesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BasisOfAccountingPolicyPolicyTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1016 - Disclosure - Summary of Significant Accounting Policies (Policies)",
     "role": "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesPolicies",
     "shortName": "Summary of Significant Accounting Policies (Policies)",
     "subGroupType": "policies",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:SignificantAccountingPoliciesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BasisOfAccountingPolicyPolicyTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R17": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:FairValueDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueByBalanceSheetGroupingTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1017 - Disclosure - Fair Value Measurements (Tables)",
     "role": "http://www.gbt.com/role/FairValueMeasurementsTables",
     "shortName": "Fair Value Measurements (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:FairValueDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueByBalanceSheetGroupingTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R18": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AvailableForSaleSecuritiesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1018 - Disclosure - Available-for-Sale Securities (Tables)",
     "role": "http://www.gbt.com/role/AvailableForSaleSecuritiesTables",
     "shortName": "Available-for-Sale Securities (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AvailableForSaleSecuritiesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R19": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:SupplementalBalanceSheetDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfInventoryCurrentTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1019 - Disclosure - Balance Sheet Components (Tables)",
     "role": "http://www.gbt.com/role/BalanceSheetComponentsTables",
     "shortName": "Balance Sheet Components (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:SupplementalBalanceSheetDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfInventoryCurrentTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R2": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:CashAndCashEquivalentsAtCarryingValue",
      "reportCount": 1,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "1002 - Statement - Condensed Consolidated Balance Sheets",
     "role": "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets",
     "shortName": "Condensed Consolidated Balance Sheets",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn12_31_2020",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:CashAndCashEquivalentsAtCarryingValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     }
    },
    "R20": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfMaturitiesOfLongTermDebtTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1020 - Disclosure - Long-term Debt (Tables)",
     "role": "http://www.gbt.com/role/LongTermDebtTables",
     "shortName": "Long-term Debt (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfMaturitiesOfLongTermDebtTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R21": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "gbt:ScheduleOfSupplementalCashFlowInformationRelatedToLeasesTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1021 - Disclosure - Commitments and Contingencies (Tables)",
     "role": "http://www.gbt.com/role/CommitmentsAndContingenciesTables",
     "shortName": "Commitments and Contingencies (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "gbt:ScheduleOfSupplementalCashFlowInformationRelatedToLeasesTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R22": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1022 - Disclosure - Stock-Based Compensation (Tables)",
     "role": "http://www.gbt.com/role/StockBasedCompensationTables",
     "shortName": "Stock-Based Compensation (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R23": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:EarningsPerShareTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1023 - Disclosure - Net Loss per Share (Tables)",
     "role": "http://www.gbt.com/role/NetLossPerShareTables",
     "shortName": "Net Loss per Share (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:EarningsPerShareTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R24": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:RetainedEarningsAccumulatedDeficit",
      "reportCount": 1,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1024 - Disclosure - Organization and Basis of Presentation - Additional Information (Detail)",
     "role": "http://www.gbt.com/role/OrganizationAndBasisOfPresentationAdditionalInformationDetail",
     "shortName": "Organization and Basis of Presentation - Additional Information (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R25": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "gbt:ConcentrationOfRiskPolicyTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021_CustomerConcentrationRiskMemberusgaapConcentrationRiskByTypeAxis_SalesRevenueProductLineMemberusgaapConcentrationRiskByBenchmarkAxis_TwoMajorCustomersMembersrtMajorCustomersAxis",
      "decimals": "2",
      "first": true,
      "lang": null,
      "name": "us-gaap:ConcentrationRiskPercentage1",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_pure",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1025 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Detail)",
     "role": "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail",
     "shortName": "Summary of Significant Accounting Policies - Additional Information (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "gbt:ConcentrationOfRiskPolicyTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021_CustomerConcentrationRiskMemberusgaapConcentrationRiskByTypeAxis_SalesRevenueProductLineMemberusgaapConcentrationRiskByBenchmarkAxis_TwoMajorCustomersMembersrtMajorCustomersAxis",
      "decimals": "2",
      "first": true,
      "lang": null,
      "name": "us-gaap:ConcentrationRiskPercentage1",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_pure",
      "xsiNil": "false"
     }
    },
    "R26": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:FairValueByBalanceSheetGroupingTextBlock",
       "us-gaap:FairValueDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021_FairValueMeasurementsRecurringMemberusgaapFairValueByMeasurementFrequencyAxis",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:InvestmentsFairValueDisclosure",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1026 - Disclosure - Fair Value Measurements - Fair Value Assets Measured on Recurring Basis (Detail)",
     "role": "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail",
     "shortName": "Fair Value Measurements - Fair Value Assets Measured on Recurring Basis (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:FairValueByBalanceSheetGroupingTextBlock",
       "us-gaap:FairValueDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021_FairValueMeasurementsRecurringMemberusgaapFairValueByMeasurementFrequencyAxis",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:InvestmentsFairValueDisclosure",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     }
    },
    "R27": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "ix:continuation",
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:AvailableForSaleSecuritiesAmortizedCost",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1027 - Disclosure - Available-for-Sale Securities - Summary of Available-for-Sale Securities (Detail)",
     "role": "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail",
     "shortName": "Available-for-Sale Securities - Summary of Available-for-Sale Securities (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "ix:continuation",
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:AvailableForSaleSecuritiesAmortizedCost",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     }
    },
    "R28": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "gbt:AvailableForSaleSecuritiesByBalanceSheetLocationClassificationTableTextBlock",
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:CashEquivalentsAtCarryingValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1028 - Disclosure - Available-for-Sale Securities - Summary of Classification of Available-for-Sale Securities on Consolidated Balance Sheets (Detail)",
     "role": "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfClassificationOfAvailableForSaleSecuritiesOnConsolidatedBalanceSheetsDetail",
     "shortName": "Available-for-Sale Securities - Summary of Classification of Available-for-Sale Securities on Consolidated Balance Sheets (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "gbt:AvailableForSaleSecuritiesByBalanceSheetLocationClassificationTableTextBlock",
       "us-gaap:InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:CashEquivalentsAtCarryingValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     }
    },
    "R29": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfInventoryCurrentTableTextBlock",
       "us-gaap:SupplementalBalanceSheetDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:InventoryRawMaterials",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1029 - Disclosure - Balance Sheet Components - Inventories (Detail)",
     "role": "http://www.gbt.com/role/BalanceSheetComponentsInventoriesDetail",
     "shortName": "Balance Sheet Components - Inventories (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfInventoryCurrentTableTextBlock",
       "us-gaap:SupplementalBalanceSheetDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:InventoryRawMaterials",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     }
    },
    "R3": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:PreferredStockParOrStatedValuePerShare",
       "div",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:PreferredStockParOrStatedValuePerShare",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD_per_Share",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "1003 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)",
     "role": "http://www.gbt.com/role/CondensedConsolidatedBalanceSheetsParenthetical",
     "shortName": "Condensed Consolidated Balance Sheets (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:PreferredStockParOrStatedValuePerShare",
       "div",
       "div",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:PreferredStockParOrStatedValuePerShare",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD_per_Share",
      "xsiNil": "false"
     }
    },
    "R30": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:PropertyPlantAndEquipmentTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:PropertyPlantAndEquipmentGross",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1030 - Disclosure - Balance Sheet Components - Property and Equipment (Detail)",
     "role": "http://www.gbt.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail",
     "shortName": "Balance Sheet Components - Property and Equipment (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:PropertyPlantAndEquipmentTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:PropertyPlantAndEquipmentGross",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     }
    },
    "R31": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P04_01_2021To06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1031 - Disclosure - Balance Sheet Components - Additional Information (Detail)",
     "role": "http://www.gbt.com/role/BalanceSheetComponentsAdditionalInformationDetail",
     "shortName": "Balance Sheet Components - Additional Information (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P04_01_2021To06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     }
    },
    "R32": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfAccruedLiabilitiesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "gbt:AccruedResearchAndDevelopmentCostsCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1032 - Disclosure - Balance Sheet Components - Accrued Liabilities (Detail)",
     "role": "http://www.gbt.com/role/BalanceSheetComponentsAccruedLiabilitiesDetail",
     "shortName": "Balance Sheet Components - Accrued Liabilities (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfAccruedLiabilitiesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "gbt:AccruedResearchAndDevelopmentCostsCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     }
    },
    "R33": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:LongTermDebtNoncurrent",
      "reportCount": 1,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1033 - Disclosure - Long-term Debt - Additional Information (Detail)",
     "role": "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail",
     "shortName": "Long-term Debt - Additional Information (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn11_30_2020",
      "decimals": "-5",
      "lang": null,
      "name": "us-gaap:DebtInstrumentUnamortizedDiscount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     }
    },
    "R34": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfMaturitiesOfLongTermDebtTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "gbt:LongTermDebtMaturitiesRepaymentsOfPrincipalAndInterestRemainderOfFiscalYear",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1034 - Disclosure - Long-term Debt-Schedule of Future payments of principal and interest on the Term Loan (Detail)",
     "role": "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail",
     "shortName": "Long-term Debt-Schedule of Future payments of principal and interest on the Term Loan (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfMaturitiesOfLongTermDebtTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "gbt:LongTermDebtMaturitiesRepaymentsOfPrincipalAndInterestRemainderOfFiscalYear",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     }
    },
    "R35": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P08_01_2018To08_31_2018",
      "decimals": "0",
      "first": true,
      "lang": null,
      "name": "gbt:LesseeLeasingArrangementsOperatingLeasesFacilitySize",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_sqft",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1035 - Disclosure - Commitments and Contingencies - Additional Information (Detail)",
     "role": "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail",
     "shortName": "Commitments and Contingencies - Additional Information (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P08_01_2018To08_31_2018",
      "decimals": "0",
      "first": true,
      "lang": null,
      "name": "gbt:LesseeLeasingArrangementsOperatingLeasesFacilitySize",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_sqft",
      "xsiNil": "false"
     }
    },
    "R36": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "gbt:ScheduleOfSupplementalCashFlowInformationRelatedToLeasesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2020To06_30_2020_AccountingStandardsUpdate201602MemberusgaapAdjustmentsForNewAccountingPronouncementsAxis",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1036 - Disclosure - Commitments and Contingencies - Supplemental cash flow information (Detail)",
     "role": "http://www.gbt.com/role/CommitmentsAndContingenciesSupplementalCashFlowInformationDetail",
     "shortName": "Commitments and Contingencies - Supplemental cash flow information (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "gbt:ScheduleOfSupplementalCashFlowInformationRelatedToLeasesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2020To06_30_2020_AccountingStandardsUpdate201602MemberusgaapAdjustmentsForNewAccountingPronouncementsAxis",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     }
    },
    "R37": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:LesseeOperatingLeaseLiabilityMaturityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1037 - Disclosure - Commitments and Contingencies - Lessee Operating Lease Liability Maturity (Detail)",
     "role": "http://www.gbt.com/role/CommitmentsAndContingenciesLesseeOperatingLeaseLiabilityMaturityDetail",
     "shortName": "Commitments and Contingencies - Lessee Operating Lease Liability Maturity (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:LesseeOperatingLeaseLiabilityMaturityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     }
    },
    "R38": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1038 - Disclosure - Stock-Based Compensation - Plan Summary - Additional Information (Detail)",
     "role": "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail",
     "shortName": "Stock-Based Compensation - Plan Summary - Additional Information (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R39": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "ix:continuation",
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn12_31_2020",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1039 - Disclosure - Stock-Based Compensation - Stock Option Activity (Detail)",
     "role": "http://www.gbt.com/role/StockBasedCompensationStockOptionActivityDetail",
     "shortName": "Stock-Based Compensation - Stock Option Activity (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "ix:continuation",
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn12_31_2020",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_shares",
      "xsiNil": "false"
     }
    },
    "R4": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "div",
       "div",
       "div",
       "div",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P04_01_2021To06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "1004 - Statement - Condensed Consolidated Statements of Operations and Comprehensive Loss",
     "role": "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss",
     "shortName": "Condensed Consolidated Statements of Operations and Comprehensive Loss",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "div",
       "div",
       "div",
       "div",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P04_01_2021To06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     }
    },
    "R40": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock",
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P04_01_2021To06_30_2021_EmployeeStockOptionMemberusgaapAwardTypeAxis",
      "decimals": "3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMinimum",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_pure",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1040 - Disclosure - Stock-Based Compensation - Valuation Assumptions for Stock Options Granted (Detail)",
     "role": "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail",
     "shortName": "Stock-Based Compensation - Valuation Assumptions for Stock Options Granted (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock",
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P04_01_2021To06_30_2021_EmployeeStockOptionMemberusgaapAwardTypeAxis",
      "decimals": "3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMinimum",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_pure",
      "xsiNil": "false"
     }
    },
    "R41": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:NonvestedRestrictedStockSharesActivityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn12_31_2020_RestrictedStockUnitsRSUMemberusgaapAwardTypeAxis_TwoThousandFifteenStockOptionAndIncentivePlanAndTwoThousandSeventeenInducementEquityPlanMemberusgaapPlanNameAxis",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1041 - Disclosure - Stock-Based Compensation - Summary of RSU Activity Granted to Employees with Service-Based Vesting (Detail)",
     "role": "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail",
     "shortName": "Stock-Based Compensation - Summary of RSU Activity Granted to Employees with Service-Based Vesting (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:NonvestedRestrictedStockSharesActivityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn12_31_2020_RestrictedStockUnitsRSUMemberusgaapAwardTypeAxis_TwoThousandFifteenStockOptionAndIncentivePlanAndTwoThousandSeventeenInducementEquityPlanMemberusgaapPlanNameAxis",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_shares",
      "xsiNil": "false"
     }
    },
    "R42": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021_MarketConditionRsuAwardsMemberusgaapAwardTypeAxis_ShareBasedCompensationAwardTrancheOneMemberusgaapVestingAxis",
      "decimals": "2",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD_per_Share",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1042 - Disclosure - Stock-Based Compensation - Summary of Share-based Compensation Arrangements by Share-based Payment Award (Detail)",
     "role": "http://www.gbt.com/role/StockBasedCompensationSummaryOfShareBasedCompensationArrangementsByShareBasedPaymentAwardDetail",
     "shortName": "Stock-Based Compensation - Summary of Share-based Compensation Arrangements by Share-based Payment Award (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021_MarketConditionRsuAwardsMemberusgaapAwardTypeAxis_ShareBasedCompensationAwardTrancheOneMemberusgaapVestingAxis",
      "decimals": "2",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD_per_Share",
      "xsiNil": "false"
     }
    },
    "R43": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfShareBasedCompensationActivityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn12_31_2020_MarketConditionAwardsGrantedToEmployeesMemberusgaapAwardTypeAxis_TwoThousandFifteenStockOptionAndIncentivePlanMemberusgaapPlanNameAxis",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber",
      "reportCount": 1,
      "unitRef": "Unit_shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1043 - Disclosure - Stock-Based Compensation - Summary of Activity of Market-Condition Awards (Detail)",
     "role": "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail",
     "shortName": "Stock-Based Compensation - Summary of Activity of Market-Condition Awards (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfShareBasedCompensationActivityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021_MarketConditionAwardsGrantedToEmployeesMemberusgaapAwardTypeAxis_TwoThousandFifteenStockOptionAndIncentivePlanMemberusgaapPlanNameAxis",
      "decimals": "INF",
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_shares",
      "xsiNil": "false"
     }
    },
    "R44": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "gbt:ScheduleOfShareBasedPaymentAwardValuationAssumptionsTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021_MarketConditionAwardsGrantedToEmployeesMemberusgaapAwardTypeAxis",
      "decimals": "2",
      "first": true,
      "lang": null,
      "name": "us-gaap:SharePrice",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD_per_Share",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1044 - Disclosure - Stock-Based Compensation - Valuation Assumptions of Market-Condition Awards (Detail)",
     "role": "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsOfMarketConditionAwardsDetail",
     "shortName": "Stock-Based Compensation - Valuation Assumptions of Market-Condition Awards (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "gbt:ScheduleOfShareBasedPaymentAwardValuationAssumptionsTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn06_30_2021_MarketConditionAwardsGrantedToEmployeesMemberusgaapAwardTypeAxis",
      "decimals": "2",
      "first": true,
      "lang": null,
      "name": "us-gaap:SharePrice",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD_per_Share",
      "xsiNil": "false"
     }
    },
    "R45": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P04_01_2021To06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:AllocatedShareBasedCompensationExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1045 - Disclosure - Stock-Based Compensation - Stock-Based Compensation Expense Recognized (Detail)",
     "role": "http://www.gbt.com/role/StockBasedCompensationStockBasedCompensationExpenseRecognizedDetail",
     "shortName": "Stock-Based Compensation - Stock-Based Compensation Expense Recognized (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P04_01_2021To06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:AllocatedShareBasedCompensationExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     }
    },
    "R46": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock",
       "us-gaap:EarningsPerShareTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P04_01_2021To06_30_2021",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_shares",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1046 - Disclosure - Net Loss per Share - Potentially Dilutive Securities that were Not Included in Diluted Net Loss per Share Calculations (Detail)",
     "role": "http://www.gbt.com/role/NetLossPerSharePotentiallyDilutiveSecuritiesThatWereNotIncludedInDilutedNetLossPerShareCalculationsDetail",
     "shortName": "Net Loss per Share - Potentially Dilutive Securities that were Not Included in Diluted Net Loss per Share Calculations (Detail)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock",
       "us-gaap:EarningsPerShareTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P04_01_2021To06_30_2021",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_shares",
      "xsiNil": "false"
     }
    },
    "R5": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "PAsOn12_31_2019",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:StockholdersEquity",
      "reportCount": 1,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "1005 - Statement - Condensed Consolidated Statements of Stockholders' Equity",
     "role": "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity",
     "shortName": "Condensed Consolidated Statements of Stockholders' Equity",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2020To03_31_2020",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:StockIssuedDuringPeriodValueStockOptionsExercised",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     }
    },
    "R6": {
     "firstAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "div",
       "div",
       "div",
       "div",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:NetIncomeLoss",
      "reportCount": 1,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "1006 - Statement - Condensed Consolidated Statements of Cash Flows",
     "role": "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows",
     "shortName": "Condensed Consolidated Statements of Cash Flows",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:DepreciationDepletionAndAmortization",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_USD",
      "xsiNil": "false"
     }
    },
    "R7": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1007 - Disclosure - Organization",
     "role": "http://www.gbt.com/role/Organization",
     "shortName": "Organization",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R8": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SignificantAccountingPoliciesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1008 - Disclosure - Summary of Significant Accounting Policies",
     "role": "http://www.gbt.com/role/SummaryOfSignificantAccountingPolicies",
     "shortName": "Summary of Significant Accounting Policies",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SignificantAccountingPoliciesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R9": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "1009 - Disclosure - Fair Value Measurements",
     "role": "http://www.gbt.com/role/FairValueMeasurements",
     "shortName": "Fair Value Measurements",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "d194083d10q.htm",
      "contextRef": "P01_01_2021To06_30_2021",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    }
   },
   "segmentCount": 45,
   "tag": {
    "dei_AmendmentFlag": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.",
        "label": "Amendment Flag"
       }
      }
     },
     "localname": "AmendmentFlag",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_CityAreaCode": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Area code of city",
        "label": "City Area Code"
       }
      }
     },
     "localname": "CityAreaCode",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_CoverAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Cover page.",
        "label": "Cover [Abstract]"
       }
      }
     },
     "localname": "CoverAbstract",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "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"
       }
      }
     },
     "localname": "CurrentFiscalYearEndDate",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "gMonthDayItemType"
    },
    "dei_DocumentFiscalPeriodFocus": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fiscal period values are FY, Q1, Q2, and Q3.  1st, 2nd and 3rd quarter 10-Q or 10-QT statements have value Q1, Q2, and Q3 respectively, with 10-K, 10-KT or other fiscal year statements having FY.",
        "label": "Document Fiscal Period Focus"
       }
      }
     },
     "localname": "DocumentFiscalPeriodFocus",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "fiscalPeriodItemType"
    },
    "dei_DocumentFiscalYearFocus": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "This is focus fiscal year of the document report in YYYY format. For a 2006 annual report, which may also provide financial information from prior periods, fiscal 2006 should be given as the fiscal year focus. Example: 2006.",
        "label": "Document Fiscal Year Focus"
       }
      }
     },
     "localname": "DocumentFiscalYearFocus",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.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 YYYY-MM-DD.",
        "label": "Document Period End Date"
       }
      }
     },
     "localname": "DocumentPeriodEndDate",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "dateItemType"
    },
    "dei_DocumentQuarterlyReport": {
     "auth_ref": [
      "r423"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true only for a form used as an quarterly report.",
        "label": "Document Quarterly Report"
       }
      }
     },
     "localname": "DocumentQuarterlyReport",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_DocumentTransitionReport": {
     "auth_ref": [
      "r424"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true only for a form used as a transition report.",
        "label": "Document Transition Report"
       }
      }
     },
     "localname": "DocumentTransitionReport",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.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"
       }
      }
     },
     "localname": "DocumentType",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "submissionTypeItemType"
    },
    "dei_EntityAddressAddressLine1": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Address Line 1 such as Attn, Building Name, Street Name",
        "label": "Entity Address, Address Line One"
       }
      }
     },
     "localname": "EntityAddressAddressLine1",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.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"
       }
      }
     },
     "localname": "EntityAddressCityOrTown",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.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"
       }
      }
     },
     "localname": "EntityAddressPostalZipCode",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.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"
       }
      }
     },
     "localname": "EntityAddressStateOrProvince",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "stateOrProvinceItemType"
    },
    "dei_EntityCentralIndexKey": {
     "auth_ref": [
      "r425"
     ],
     "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"
       }
      }
     },
     "localname": "EntityCentralIndexKey",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.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"
       }
      }
     },
     "localname": "EntityCommonStockSharesOutstanding",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.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"
       }
      }
     },
     "localname": "EntityCurrentReportingStatus",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityEmergingGrowthCompany": {
     "auth_ref": [
      "r425"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicate if registrant meets the emerging growth company criteria.",
        "label": "Entity Emerging Growth Company"
       }
      }
     },
     "localname": "EntityEmergingGrowthCompany",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.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"
       }
      }
     },
     "localname": "EntityFileNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "fileNumberItemType"
    },
    "dei_EntityFilerCategory": {
     "auth_ref": [
      "r425"
     ],
     "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"
       }
      }
     },
     "localname": "EntityFilerCategory",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.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"
       }
      }
     },
     "localname": "EntityIncorporationStateCountryCode",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "edgarStateCountryItemType"
    },
    "dei_EntityInteractiveDataCurrent": {
     "auth_ref": [
      "r426"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true when the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).",
        "label": "Entity Interactive Data Current"
       }
      }
     },
     "localname": "EntityInteractiveDataCurrent",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityRegistrantName": {
     "auth_ref": [
      "r425"
     ],
     "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"
       }
      }
     },
     "localname": "EntityRegistrantName",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityShellCompany": {
     "auth_ref": [
      "r425"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Boolean flag that is true when the registrant is a shell company as defined in Rule 12b-2 of the Exchange Act.",
        "label": "Entity Shell Company"
       }
      }
     },
     "localname": "EntityShellCompany",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntitySmallBusiness": {
     "auth_ref": [
      "r425"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Indicates that the company is a Smaller Reporting Company (SRC).",
        "label": "Entity Small Business"
       }
      }
     },
     "localname": "EntitySmallBusiness",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntityTaxIdentificationNumber": {
     "auth_ref": [
      "r425"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.",
        "label": "Entity Tax Identification Number"
       }
      }
     },
     "localname": "EntityTaxIdentificationNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "employerIdItemType"
    },
    "dei_LocalPhoneNumber": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Local phone number for entity.",
        "label": "Local Phone Number"
       }
      }
     },
     "localname": "LocalPhoneNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_Security12bTitle": {
     "auth_ref": [
      "r421"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Title of a 12(b) registered security.",
        "label": "Title of 12(b) Security"
       }
      }
     },
     "localname": "Security12bTitle",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "securityTitleItemType"
    },
    "dei_SecurityExchangeName": {
     "auth_ref": [
      "r422"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Name of the Exchange on which a security is registered.",
        "label": "Security Exchange Name"
       }
      }
     },
     "localname": "SecurityExchangeName",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.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"
       }
      }
     },
     "localname": "TradingSymbol",
     "nsuri": "http://xbrl.sec.gov/dei/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CoverPage"
     ],
     "xbrltype": "tradingSymbolItemType"
    },
    "gbt_AccountingPronouncementIssuedButNotYetAdoptedPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy pertaining to accounting pronouncement issued but not yet adopted.",
        "label": "Accounting Pronouncement Issued But Not Yet Adopted [Policy Text Block]",
        "terseLabel": "Accounting Pronouncement Issued But Not Yet Adopted"
       }
      }
     },
     "localname": "AccountingPronouncementIssuedButNotYetAdoptedPolicyTextBlock",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "gbt_AccretionOfPaydownFee": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accretion Of Paydown Fee.",
        "label": "Accretion Of Paydown Fee",
        "terseLabel": "Accretion of Paydown Fee"
       }
      }
     },
     "localname": "AccretionOfPaydownFee",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_AccruedIssuanceCostsIncurredDuringNonCashOrPartialNonCashTransaction": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of accrued issuance costs that were incurred during a noncash or partial noncash transaction.",
        "label": "Accrued Issuance Costs Incurred During Non Cash Or Partial Non Cash Transaction",
        "verboseLabel": "Accrued issuance costs"
       }
      }
     },
     "localname": "AccruedIssuanceCostsIncurredDuringNonCashOrPartialNonCashTransaction",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_AccruedManufacturingExpensesCurrent": {
     "auth_ref": [],
     "calculation": {
      "http://www.gbt.com/role/BalanceSheetComponentsAccruedLiabilitiesDetail": {
       "order": 2.0,
       "parentTag": "us-gaap_AccruedLiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accrued manufacturing expenses current.",
        "label": "Accrued Manufacturing Expenses Current",
        "terseLabel": "Accrued manufacturing costs"
       }
      }
     },
     "localname": "AccruedManufacturingExpensesCurrent",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsAccruedLiabilitiesDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_AccruedPurchasesOfPropertyAndEquipment": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accrued purchases of property and equipment.",
        "label": "Accrued Purchases Of Property And Equipment",
        "terseLabel": "Accrued purchase of property and equipment"
       }
      }
     },
     "localname": "AccruedPurchasesOfPropertyAndEquipment",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_AccruedResearchAndDevelopmentCostsCurrent": {
     "auth_ref": [],
     "calculation": {
      "http://www.gbt.com/role/BalanceSheetComponentsAccruedLiabilitiesDetail": {
       "order": 5.0,
       "parentTag": "us-gaap_AccruedLiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accrued research and development costs current.",
        "label": "Accrued Research And Development Costs Current",
        "terseLabel": "Accrued research and development costs"
       }
      }
     },
     "localname": "AccruedResearchAndDevelopmentCostsCurrent",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsAccruedLiabilitiesDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_AccuredSalesDeductionsCurrent": {
     "auth_ref": [],
     "calculation": {
      "http://www.gbt.com/role/BalanceSheetComponentsAccruedLiabilitiesDetail": {
       "order": 3.0,
       "parentTag": "us-gaap_AccruedLiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accured sales deductions current.",
        "label": "Accured Sales Deductions Current",
        "terseLabel": "Accrued sales deductions"
       }
      }
     },
     "localname": "AccuredSalesDeductionsCurrent",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsAccruedLiabilitiesDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_AvailableForSaleSecuritiesByBalanceSheetLocationClassificationTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Available for sale securities by balance sheet location classification.",
        "label": "Available For Sale Securities By Balance Sheet Location Classification [Table Text Block]",
        "terseLabel": "Summary of Classification of Available-for-Sale Securities on Consolidated Balance Sheets"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesByBalanceSheetLocationClassificationTableTextBlock",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "gbt_BalanceSheetComponentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Balance Sheet Components [Abstract]",
        "label": "Balance Sheet Components [Abstract]"
       }
      }
     },
     "localname": "BalanceSheetComponentsAbstract",
     "nsuri": "http://www.gbt.com/20210630",
     "xbrltype": "stringItemType"
    },
    "gbt_CapitalizedDepreciationExpenses": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Capitalized depreciation expenses.",
        "label": "Capitalized Depreciation Expenses",
        "terseLabel": "Capitalized depreciation expenses"
       }
      }
     },
     "localname": "CapitalizedDepreciationExpenses",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_CommitmentAndContingenciesLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Commitment And Contingencies [Line Items]",
        "label": "Commitment And Contingencies [Line Items]",
        "terseLabel": "Commitment And Contingencies [Line Items]"
       }
      }
     },
     "localname": "CommitmentAndContingenciesLineItems",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail",
      "http://www.gbt.com/role/CommitmentsAndContingenciesSupplementalCashFlowInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "gbt_CommitmentsAndContingenciesDisclosureTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Commitments And Contingencies Disclosure [Table]",
        "label": "Commitments And Contingencies Disclosure [Table]",
        "terseLabel": "Commitments And Contingencies Disclosure [Table]"
       }
      }
     },
     "localname": "CommitmentsAndContingenciesDisclosureTable",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail",
      "http://www.gbt.com/role/CommitmentsAndContingenciesSupplementalCashFlowInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "gbt_ConcentrationOfRiskPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Concentration of risk policy text block.",
        "label": "Concentration of Risk [Policy Text Block]",
        "verboseLabel": "Concentration of Risk"
       }
      }
     },
     "localname": "ConcentrationOfRiskPolicyTextBlock",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "gbt_DebtInstrumentAdditionalInterestRateOnDebtDefault": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Debt Instrument Additional Interest Rate On Debt Default",
        "label": "Debt Instrument Additional Interest Rate On Debt Default",
        "terseLabel": "Debt Instrument Additional Interest Rate On Debt Default"
       }
      }
     },
     "localname": "DebtInstrumentAdditionalInterestRateOnDebtDefault",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "percentItemType"
    },
    "gbt_DebtInstrumentAdditionalPaydownFeePercentage": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Debt instrument additional paydown fee percentage.",
        "label": "Debt Instrument Additional Paydown Fee Percentage",
        "terseLabel": "Debt additional paydown fee"
       }
      }
     },
     "localname": "DebtInstrumentAdditionalPaydownFeePercentage",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "percentItemType"
    },
    "gbt_DebtInstrumentPeriodicPaymentOfInterest": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Debt instrument periodic payment of interest.",
        "label": "Debt Instrument Periodic Payment Of Interest"
       }
      }
     },
     "localname": "DebtInstrumentPeriodicPaymentOfInterest",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "gbt_DebtInstrumentPeriodicPaymentOfInterestTerm": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Debt instrument periodic payment of interest term.",
        "label": "Debt Instrument Periodic Payment Of Interest Term"
       }
      }
     },
     "localname": "DebtInstrumentPeriodicPaymentOfInterestTerm",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "gbt_DebtInstrumentPrepaymentFeePercentage": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Debt instrument prepayment fee percentage.",
        "label": "Debt Instrument Prepayment Fee Percentage",
        "terseLabel": "Debt prepayment fee"
       }
      }
     },
     "localname": "DebtInstrumentPrepaymentFeePercentage",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "percentItemType"
    },
    "gbt_DebtPaydownFee": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Debt Paydown Fee.",
        "label": "Debt Paydown Fee",
        "terseLabel": "Less amount representing Paydown Fee"
       }
      }
     },
     "localname": "DebtPaydownFee",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_IncreaseDecreaseInOperatingLeaseLiabilities": {
     "auth_ref": [],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 17.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "definitionGuidance": "Operating lease liabilities",
        "documentation": "Amount of increase (decrease) of\u00a0operating lease liabilities during period.",
        "label": "Increase Decrease In Operating Lease Liabilities"
       }
      }
     },
     "localname": "IncreaseDecreaseInOperatingLeaseLiabilities",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_LeaseholdImprovementPaidForByLandlord": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Leasehold improvements paid for by landlord.",
        "label": "Leasehold Improvement Paid For By Landlord",
        "terseLabel": "Leasehold improvements paid for by landlord"
       }
      }
     },
     "localname": "LeaseholdImprovementPaidForByLandlord",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_LesseeLeasingArrangementsOperatingLeasesFacilitySize": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Lessee Leasing Arrangements, Operating Leases, Facility Size",
        "label": "Lessee Leasing Arrangements Operating Leases Facility Size",
        "terseLabel": "Facility size"
       }
      }
     },
     "localname": "LesseeLeasingArrangementsOperatingLeasesFacilitySize",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "areaItemType"
    },
    "gbt_LesseeOperatingLeaseLiabilityToBePaidAfterYearFour": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Lessee Operating Lease Liability To Be Paid After Year Four.",
        "label": "Lessee Operating Lease Liability To Be Paid After Year Four",
        "terseLabel": "Thereafter"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityToBePaidAfterYearFour",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesLesseeOperatingLeaseLiabilityMaturityDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_LineOfCreditAdditionalBorrowingCapacity": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line of credit additional borrowing capacity.",
        "label": "Line Of Credit Additional Borrowing Capacity",
        "terseLabel": "Debt additional borrowing capacity"
       }
      }
     },
     "localname": "LineOfCreditAdditionalBorrowingCapacity",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_LongTermDebtDiscountOnNotesPayable": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long Term Debt Discount On Notes Payable.",
        "label": "Long Term Debt Discount On Notes Payable",
        "terseLabel": "Discount on notes payable"
       }
      }
     },
     "localname": "LongTermDebtDiscountOnNotesPayable",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_LongTermDebtMaturitiesRepaymentsOfPrincipalAndInterestInNextTwelveMonths": {
     "auth_ref": [],
     "calculation": {
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail": {
       "order": 1.0,
       "parentTag": "us-gaap_LongTermDebt",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long term debt maturities repayments of principal and interest In next twelve months.",
        "label": "Long Term Debt Maturities Repayments Of Principal And Interest In Next Twelve Months",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "LongTermDebtMaturitiesRepaymentsOfPrincipalAndInterestInNextTwelveMonths",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_LongTermDebtMaturitiesRepaymentsOfPrincipalAndInterestInYearFour": {
     "auth_ref": [],
     "calculation": {
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail": {
       "order": 4.0,
       "parentTag": "us-gaap_LongTermDebt",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long Term Debt Maturities Repayments Of Principal And Interest In Year Four",
        "label": "Long Term Debt Maturities Repayments Of Principal And Interest In Year Four",
        "terseLabel": "2025"
       }
      }
     },
     "localname": "LongTermDebtMaturitiesRepaymentsOfPrincipalAndInterestInYearFour",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_LongTermDebtMaturitiesRepaymentsOfPrincipalAndInterestInYearThree": {
     "auth_ref": [],
     "calculation": {
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail": {
       "order": 3.0,
       "parentTag": "us-gaap_LongTermDebt",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long Term Debt Maturities Repayments Of Principal And Interest In Year Three",
        "label": "Long Term Debt Maturities Repayments Of Principal And Interest In Year Three",
        "terseLabel": "2024"
       }
      }
     },
     "localname": "LongTermDebtMaturitiesRepaymentsOfPrincipalAndInterestInYearThree",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_LongTermDebtMaturitiesRepaymentsOfPrincipalAndInterestInYearTwo": {
     "auth_ref": [],
     "calculation": {
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail": {
       "order": 2.0,
       "parentTag": "us-gaap_LongTermDebt",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long Term Debt Maturities Repayments Of Principal And Interest In Year Two.",
        "label": "Long Term Debt Maturities Repayments Of Principal And Interest In Year Two",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "LongTermDebtMaturitiesRepaymentsOfPrincipalAndInterestInYearTwo",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_LongTermDebtMaturitiesRepaymentsOfPrincipalAndInterestRemainderOfFiscalYear": {
     "auth_ref": [],
     "calculation": {
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail": {
       "order": 5.0,
       "parentTag": "us-gaap_LongTermDebt",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long term debt maturities repayments of principal and interest remainder of fiscal year.",
        "label": "Long Term Debt Maturities Repayments Of Principal And Interest Remainder Of Fiscal Year",
        "terseLabel": "2021 (six months)"
       }
      }
     },
     "localname": "LongTermDebtMaturitiesRepaymentsOfPrincipalAndInterestRemainderOfFiscalYear",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_MarketConditionAwardsGrantedToEmployeesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Market condition awards granted to employees.",
        "label": "Market Condition Awards Granted To Employees [Member]",
        "terseLabel": "Market Condition Awards Granted to Employees [Member]"
       }
      }
     },
     "localname": "MarketConditionAwardsGrantedToEmployeesMember",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail",
      "http://www.gbt.com/role/StockBasedCompensationTables",
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsOfMarketConditionAwardsDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "gbt_MarketConditionRsuAwardsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Market Condition RSU Awards.",
        "label": "Market Condition RSU Awards [Member]",
        "terseLabel": "Market-Condition RSU Awards [Member]"
       }
      }
     },
     "localname": "MarketConditionRsuAwardsMember",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfShareBasedCompensationArrangementsByShareBasedPaymentAwardDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "gbt_MilestonePaymentTypeAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Milestone Payment Type [Axis]"
       }
      }
     },
     "localname": "MilestonePaymentTypeAxis",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "gbt_MilestonePaymentTypeDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Milestone Payment Type [Domain]"
       }
      }
     },
     "localname": "MilestonePaymentTypeDomain",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "gbt_OperatingLeaseLeaseExpirationPeriod": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Operating lease lease expiration period.",
        "label": "Operating Lease Lease Expiration Period",
        "terseLabel": "Operating lease term"
       }
      }
     },
     "localname": "OperatingLeaseLeaseExpirationPeriod",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "durationItemType"
    },
    "gbt_OperatingLeaseRemainingLeaseTerm": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Operating lease remaining lease term.",
        "label": "Operating Lease Remaining Lease Term",
        "verboseLabel": "Operating lease remaining lease term"
       }
      }
     },
     "localname": "OperatingLeaseRemainingLeaseTerm",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "durationItemType"
    },
    "gbt_OperatingLeasesFutureMinimumPaymentsDueInTenYears": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Operating leases future minimum payments due in ten years.",
        "label": "Operating Leases Future Minimum Payments Due In Ten Years",
        "terseLabel": "Future minimum rental payments under the Lease term"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsDueInTenYears",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_OptionToExtendOperatingLeaseTerm": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Option To Extend Operating Lease Term",
        "label": "Option To Extend Operating Lease Term",
        "terseLabel": "Operating lease term, optional extension"
       }
      }
     },
     "localname": "OptionToExtendOperatingLeaseTerm",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "durationItemType"
    },
    "gbt_OtherNonoperatingExpensesNet": {
     "auth_ref": [],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 10.0,
       "parentTag": "us-gaap_OtherNonoperatingIncomeExpense",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Other nonoperating expenses net.",
        "label": "Other Nonoperating Expenses Net",
        "negatedLabel": "Other expenses, net"
       }
      }
     },
     "localname": "OtherNonoperatingExpensesNet",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_PaymentsOfOtherDebtIssuanceCosts": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Payments of other debt issuance costs.",
        "label": "Payments Of Other Debt Issuance Costs",
        "terseLabel": "Other debt issuance cost paid"
       }
      }
     },
     "localname": "PaymentsOfOtherDebtIssuanceCosts",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_ProceedsFromExerciseOfStockOptionsAndESPP": {
     "auth_ref": [],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 8.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Proceeds from exercise of stock options and ESPP.",
        "label": "Proceeds from exercise of stock options and ESPP",
        "terseLabel": "Proceeds from issuance of common stock in settlement of employee stock purchase plan and exercise of stock options"
       }
      }
     },
     "localname": "ProceedsFromExerciseOfStockOptionsAndESPP",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "gbt_RestrictedStockUnitMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Restricted stock unit.",
        "label": "Restricted Stock Unit [Member]",
        "terseLabel": "Restricted Stock Units [Member]"
       }
      }
     },
     "localname": "RestrictedStockUnitMember",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "domainItemType"
    },
    "gbt_ScheduleOfShareBasedPaymentAwardValuationAssumptionsTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule Of Share Based Payment Award Valuation Assumptions Table [Text Block]",
        "label": "Schedule Of Share Based Payment Award Valuation Assumptions [Table Text Block]",
        "terseLabel": "Valuation Assumptions of Market-Condition Awards"
       }
      }
     },
     "localname": "ScheduleOfShareBasedPaymentAwardValuationAssumptionsTableTextBlock",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "gbt_ScheduleOfSupplementalCashFlowInformationRelatedToLeasesTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule of supplemental cash flow information related to leases.",
        "label": "Schedule Of Supplemental Cash Flow Information Related To Leases [Table Text Block]",
        "terseLabel": "Summary of supplemental information related to leases"
       }
      }
     },
     "localname": "ScheduleOfSupplementalCashFlowInformationRelatedToLeasesTableTextBlock",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "gbt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageRemainingContractualTerms": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Share based compensation arrangement by share based payment award equity instruments other than options forfeitures weighted average remaining contractual terms.",
        "label": "Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeitures Weighted Average Remaining Contractual Terms",
        "terseLabel": "Non-vested units, Weighted-Average remaining vesting period (years) forfeited"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageRemainingContractualTerms",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail"
     ],
     "xbrltype": "durationItemType"
    },
    "gbt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsWeightedAverageRemainingContractualTerms": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Share based compensation arrangement by share based payment award equity instruments other than options grants weighted average remaining contractual terms.",
        "label": "Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants Weighted Average Remaining Contractual Terms",
        "terseLabel": "Non-vested units, Weighted-Average remaining vesting period (years) granted"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsWeightedAverageRemainingContractualTerms",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail"
     ],
     "xbrltype": "durationItemType"
    },
    "gbt_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceAndAdditionalDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Share-based Compensation Arrangement by Share-based Payment Award, Options Outstanding, Weighted Average Exercise Price, and Additional Disclosures [Abstract]",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options Outstanding, Weighted Average Exercise Price, and Additional Disclosures [Abstract]"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceAndAdditionalDisclosuresAbstract",
     "nsuri": "http://www.gbt.com/20210630",
     "xbrltype": "stringItemType"
    },
    "gbt_SharebasedcompensationarrangementbysharebasedpaymentawardoptionsoutstandingweightedaverageexercisepriceandadditionaldisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceAndAdditionalDisclosures [Abstract]",
        "terseLabel": "Share-based Compensation Arrangement by Share-based Payment Award, Options Outstanding, Weighted Average Exercise Price, and Additional Disclosures [Abstract]"
       }
      }
     },
     "localname": "SharebasedcompensationarrangementbysharebasedpaymentawardoptionsoutstandingweightedaverageexercisepriceandadditionaldisclosuresAbstract",
     "nsuri": "http://www.gbt.com/20210630",
     "xbrltype": "stringItemType"
    },
    "gbt_SignificantAccountingPoliciesPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Significant accounting policies.",
        "label": "Significant Accounting Policies [Policy Text Block]",
        "terseLabel": "Significant Accounting Policies"
       }
      }
     },
     "localname": "SignificantAccountingPoliciesPolicyTextBlock",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "gbt_SummaryOfSignificantAccountingPoliciesLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Summary Of Significant Accounting Policies [Line Items]",
        "label": "Summary Of Significant Accounting Policies [Line Items]",
        "terseLabel": "Summary Of Significant Accounting Policies [Line Items]"
       }
      }
     },
     "localname": "SummaryOfSignificantAccountingPoliciesLineItems",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "gbt_SummaryOfSignificantAccountingPoliciesTable": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Summary Of Significant Accounting Policies [Table]",
        "label": "Summary Of Significant Accounting Policies [Table]",
        "terseLabel": "Summary Of Significant Accounting Policies [Table]"
       }
      }
     },
     "localname": "SummaryOfSignificantAccountingPoliciesTable",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "gbt_TermLoanMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Term loan.",
        "label": "Term Loan [Member]",
        "terseLabel": "Term Loan"
       }
      }
     },
     "localname": "TermLoanMember",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "gbt_TwoMajorCustomersMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Two Major Customers [Member]",
        "terseLabel": "Two Major Customers [Member]"
       }
      }
     },
     "localname": "TwoMajorCustomersMember",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "gbt_TwoThousandFifteenStockOptionAndIncentivePlanAndTwoThousandSeventeenInducementEquityPlanMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Two thousand fifteen stock option and incentive plan and two thousand seventeen inducement equity plan.",
        "label": "Two Thousand Fifteen Stock Option And Incentive Plan And Two Thousand Seventeen Inducement Equity Plan [Member]",
        "terseLabel": "2017 Inducement Plan and 2015 Plan [Member]"
       }
      }
     },
     "localname": "TwoThousandFifteenStockOptionAndIncentivePlanAndTwoThousandSeventeenInducementEquityPlanMember",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "gbt_TwoThousandFifteenStockOptionAndIncentivePlanMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "2015 stock option and incentive plan.",
        "label": "Two Thousand Fifteen Stock Option And Incentive Plan [Member]",
        "terseLabel": "2015 Plan [Member]"
       }
      }
     },
     "localname": "TwoThousandFifteenStockOptionAndIncentivePlanMember",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "gbt_TwoThousandSeventeenInducementEquityPlanMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "2017 Inducement Equity Plan.",
        "label": "Two Thousand Seventeen Inducement Equity Plan [Member]",
        "terseLabel": "2017 Inducement Equity Plan [Member]"
       }
      }
     },
     "localname": "TwoThousandSeventeenInducementEquityPlanMember",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "gbt_TypeOfDepositAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Type of Deposit [Axis]"
       }
      }
     },
     "localname": "TypeOfDepositAxis",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "gbt_TypeOfDepositDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Type of Deposit [Domain]"
       }
      }
     },
     "localname": "TypeOfDepositDomain",
     "nsuri": "http://www.gbt.com/20210630",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_CounterpartyNameAxis": {
     "auth_ref": [
      "r52",
      "r94"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Counterparty Name [Axis]",
        "terseLabel": "Counterparty Name [Axis]"
       }
      }
     },
     "localname": "CounterpartyNameAxis",
     "nsuri": "http://fasb.org/srt/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail",
      "http://www.gbt.com/role/OrganizationAndBasisOfPresentationAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_MajorCustomersAxis": {
     "auth_ref": [
      "r150",
      "r217",
      "r218",
      "r400"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Customer [Axis]"
       }
      }
     },
     "localname": "MajorCustomersAxis",
     "nsuri": "http://fasb.org/srt/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_MaximumMember": {
     "auth_ref": [
      "r228",
      "r229",
      "r341",
      "r342",
      "r343",
      "r344",
      "r345",
      "r346",
      "r365",
      "r399",
      "r401"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Maximum [Member]",
        "terseLabel": "Maximum [Member]",
        "verboseLabel": "Maximum"
       }
      }
     },
     "localname": "MaximumMember",
     "nsuri": "http://fasb.org/srt/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail",
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_MinimumMember": {
     "auth_ref": [
      "r228",
      "r229",
      "r341",
      "r342",
      "r343",
      "r344",
      "r345",
      "r346",
      "r365",
      "r399",
      "r401"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Minimum [Member]",
        "terseLabel": "Minimum [Member]",
        "verboseLabel": "Minimum"
       }
      }
     },
     "localname": "MinimumMember",
     "nsuri": "http://fasb.org/srt/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail",
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_NameOfMajorCustomerDomain": {
     "auth_ref": [
      "r150",
      "r217",
      "r218",
      "r400"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Customer [Domain]"
       }
      }
     },
     "localname": "NameOfMajorCustomerDomain",
     "nsuri": "http://fasb.org/srt/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RangeAxis": {
     "auth_ref": [
      "r219",
      "r228",
      "r229",
      "r341",
      "r342",
      "r343",
      "r344",
      "r345",
      "r346",
      "r365",
      "r399",
      "r401"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Range [Axis]",
        "terseLabel": "Range [Axis]"
       }
      }
     },
     "localname": "RangeAxis",
     "nsuri": "http://fasb.org/srt/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail",
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail",
      "http://www.gbt.com/role/OrganizationAndBasisOfPresentationAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail",
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsOfMarketConditionAwardsDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_RangeMember": {
     "auth_ref": [
      "r219",
      "r228",
      "r229",
      "r341",
      "r342",
      "r343",
      "r344",
      "r345",
      "r346",
      "r365",
      "r399",
      "r401"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Range [Domain]",
        "terseLabel": "Range [Domain]"
       }
      }
     },
     "localname": "RangeMember",
     "nsuri": "http://fasb.org/srt/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail",
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail",
      "http://www.gbt.com/role/OrganizationAndBasisOfPresentationAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail",
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsOfMarketConditionAwardsDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RepurchaseAgreementCounterpartyNameDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Counterparty Name [Domain]",
        "terseLabel": "Counterparty Name [Domain]"
       }
      }
     },
     "localname": "RepurchaseAgreementCounterpartyNameDomain",
     "nsuri": "http://fasb.org/srt/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail",
      "http://www.gbt.com/role/OrganizationAndBasisOfPresentationAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RestatementAxis": {
     "auth_ref": [
      "r96",
      "r97",
      "r98",
      "r99",
      "r100",
      "r101",
      "r104",
      "r105",
      "r106",
      "r108",
      "r109",
      "r110",
      "r111",
      "r112",
      "r118",
      "r171",
      "r172",
      "r270",
      "r280",
      "r404",
      "r405",
      "r406",
      "r407",
      "r408",
      "r409",
      "r410",
      "r411",
      "r412",
      "r413"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Restatement [Axis]"
       }
      }
     },
     "localname": "RestatementAxis",
     "nsuri": "http://fasb.org/srt/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_RestatementDomain": {
     "auth_ref": [
      "r96",
      "r97",
      "r98",
      "r99",
      "r100",
      "r101",
      "r104",
      "r105",
      "r106",
      "r108",
      "r109",
      "r110",
      "r111",
      "r112",
      "r118",
      "r171",
      "r172",
      "r270",
      "r280",
      "r404",
      "r405",
      "r406",
      "r407",
      "r408",
      "r409",
      "r410",
      "r411",
      "r412",
      "r413"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Restatement [Domain]"
       }
      }
     },
     "localname": "RestatementDomain",
     "nsuri": "http://fasb.org/srt/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_TitleOfIndividualAxis": {
     "auth_ref": [
      "r151",
      "r333"
     ],
     "lang": {
      "en-us": {
       "role": {
        "label": "Title of Individual [Axis]",
        "terseLabel": "Title of Individual [Axis]"
       }
      }
     },
     "localname": "TitleOfIndividualAxis",
     "nsuri": "http://fasb.org/srt/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_TitleOfIndividualWithRelationshipToEntityDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Title of Individual [Domain]",
        "terseLabel": "Relationship to Entity [Domain]"
       }
      }
     },
     "localname": "TitleOfIndividualWithRelationshipToEntityDomain",
     "nsuri": "http://fasb.org/srt/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccountingPoliciesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Accounting Policies [Abstract]"
       }
      }
     },
     "localname": "AccountingPoliciesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccountingStandardsUpdate201602Member": {
     "auth_ref": [
      "r319"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesSupplementalCashFlowInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccountsPayableCurrent": {
     "auth_ref": [
      "r35"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 16.0,
       "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "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]"
       }
      }
     },
     "localname": "AccountsReceivableMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments": {
     "auth_ref": [
      "r84"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 22.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The sum of the periodic adjustments of the differences between securities' face values and purchase prices that are charged against earnings. This is called accretion if the security was purchased at a discount and amortization if it was purchased at premium. As a noncash item, this element is an adjustment to net income when calculating cash provided by or used in operations using the indirect method.",
        "label": "Accretion (Amortization) of Discounts and Premiums, Investments",
        "negatedLabel": "Amortization (accretion) of premium (discount) on marketable securities"
       }
      }
     },
     "localname": "AccretionAmortizationOfDiscountsAndPremiumsInvestments",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccruedLiabilitiesCurrent": {
     "auth_ref": [
      "r38"
     ],
     "calculation": {
      "http://www.gbt.com/role/BalanceSheetComponentsAccruedLiabilitiesDetail": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 17.0,
       "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": "Total accrued liabilities"
       }
      }
     },
     "localname": "AccruedLiabilitiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsAccruedLiabilitiesDetail",
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccruedProfessionalFeesCurrent": {
     "auth_ref": [
      "r7",
      "r8",
      "r38"
     ],
     "calculation": {
      "http://www.gbt.com/role/BalanceSheetComponentsAccruedLiabilitiesDetail": {
       "order": 4.0,
       "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 through that date and payable for professional fees, such as for legal and accounting services received. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
        "label": "Accrued Professional Fees, Current",
        "verboseLabel": "Accrued professional and consulting services"
       }
      }
     },
     "localname": "AccruedProfessionalFeesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsAccruedLiabilitiesDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment": {
     "auth_ref": [
      "r33",
      "r190"
     ],
     "calculation": {
      "http://www.gbt.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail": {
       "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": "Less: accumulated depreciation and amortization"
       }
      }
     },
     "localname": "AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax": {
     "auth_ref": [
      "r21",
      "r57",
      "r58",
      "r59",
      "r391",
      "r409",
      "r413"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 24.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.",
        "label": "Accumulated Other Comprehensive Income (Loss), Net of Tax",
        "terseLabel": "Accumulated other comprehensive loss"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeLossNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeMember": {
     "auth_ref": [
      "r56",
      "r59",
      "r60",
      "r96",
      "r97",
      "r99",
      "r289",
      "r404",
      "r405"
     ],
     "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 Income [Member]"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AdditionalPaidInCapital": {
     "auth_ref": [
      "r19",
      "r270"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 23.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders. Includes adjustments to additional paid in capital. Some examples of such adjustments include recording the issuance of debt with a beneficial conversion feature and certain tax consequences of equity instruments awarded to employees. Use this element for the aggregate amount of additional paid-in capital associated with common and preferred stock. For additional paid-in capital associated with only common stock, use the element additional paid in capital, common stock. For additional paid-in capital associated with only preferred stock, use the element additional paid in capital, preferred stock.",
        "label": "Additional Paid in Capital",
        "terseLabel": "Additional paid-in capital"
       }
      }
     },
     "localname": "AdditionalPaidInCapital",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AdditionalPaidInCapitalMember": {
     "auth_ref": [
      "r96",
      "r97",
      "r99",
      "r267",
      "r268",
      "r269"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders.",
        "label": "Additional Paid-in Capital [Member]",
        "terseLabel": "Additional Paid-In Capital [Member]"
       }
      }
     },
     "localname": "AdditionalPaidInCapitalMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AdjustmentsForNewAccountingPronouncementsAxis": {
     "auth_ref": [
      "r100",
      "r101",
      "r102",
      "r103",
      "r167",
      "r168",
      "r169",
      "r170",
      "r171",
      "r172",
      "r263",
      "r264",
      "r265",
      "r266",
      "r267",
      "r268",
      "r269",
      "r270",
      "r277",
      "r278",
      "r279",
      "r280",
      "r368",
      "r369",
      "r370",
      "r402",
      "r403",
      "r404",
      "r405",
      "r406",
      "r407",
      "r408",
      "r409",
      "r410",
      "r411",
      "r412",
      "r413"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by amendment to accounting standards.",
        "label": "Adjustments for New Accounting Pronouncements [Axis]",
        "terseLabel": "Adjustments for New Accounting Pronouncements [Axis]"
       }
      }
     },
     "localname": "AdjustmentsForNewAccountingPronouncementsAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesSupplementalCashFlowInformationDetail",
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue": {
     "auth_ref": [
      "r230",
      "r232",
      "r273",
      "r274"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase to additional paid-in capital (APIC) for recognition of cost for award under share-based payment arrangement.",
        "label": "Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition",
        "verboseLabel": "Stock-based compensation"
       }
      }
     },
     "localname": "AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]",
        "terseLabel": "Adjustments to reconcile net loss to net cash used in operating activities:"
       }
      }
     },
     "localname": "AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AllocatedShareBasedCompensationExpense": {
     "auth_ref": [
      "r232",
      "r259",
      "r272"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.",
        "label": "Allocated Share-based Compensation Expense",
        "terseLabel": "Total stock-based compensation expense"
       }
      }
     },
     "localname": "AllocatedShareBasedCompensationExpense",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationStockBasedCompensationExpenseRecognizedDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AmortizationOfFinancingCostsAndDiscounts": {
     "auth_ref": [
      "r83",
      "r315"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 25.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of amortization expense attributable to debt discount (premium) and debt issuance costs.",
        "label": "Amortization of Debt Issuance Costs and Discounts",
        "terseLabel": "Non-cash interest expense"
       }
      }
     },
     "localname": "AmortizationOfFinancingCostsAndDiscounts",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AmortizationOfLeaseIncentives": {
     "auth_ref": [
      "r317",
      "r318"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of amortization of lease incentive costs incurred by the lessor for the benefit of the lessee.",
        "label": "Amortization of Lease Incentives",
        "terseLabel": "Tenant inducement"
       }
      }
     },
     "localname": "AmortizationOfLeaseIncentives",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount": {
     "auth_ref": [
      "r115"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.",
        "label": "Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount",
        "terseLabel": "Antidilutive securities excluded from earnings per share"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/NetLossPerSharePotentiallyDilutiveSecuritiesThatWereNotIncludedInDilutedNetLossPerShareCalculationsDetail"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis": {
     "auth_ref": [
      "r115"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of antidilutive security.",
        "label": "Antidilutive Securities [Axis]",
        "terseLabel": "Antidilutive Securities [Axis]"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/NetLossPerSharePotentiallyDilutiveSecuritiesThatWereNotIncludedInDilutedNetLossPerShareCalculationsDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems": {
     "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": "Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]",
        "terseLabel": "Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/NetLossPerSharePotentiallyDilutiveSecuritiesThatWereNotIncludedInDilutedNetLossPerShareCalculationsDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AntidilutiveSecuritiesNameDomain": {
     "auth_ref": [
      "r115"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Incremental common shares attributable to securities that were not included in diluted earnings per share (EPS) because to do so would increase EPS amounts or decrease loss per share amounts for the period presented.",
        "label": "Antidilutive Securities, Name [Domain]",
        "terseLabel": "Antidilutive Securities, Name [Domain]"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/NetLossPerSharePotentiallyDilutiveSecuritiesThatWereNotIncludedInDilutedNetLossPerShareCalculationsDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_Assets": {
     "auth_ref": [
      "r93",
      "r137",
      "r140",
      "r146",
      "r166",
      "r285",
      "r290",
      "r305",
      "r374",
      "r389"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Assets [Abstract]",
        "terseLabel": "Assets"
       }
      }
     },
     "localname": "AssetsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AssetsCurrent": {
     "auth_ref": [
      "r4",
      "r5",
      "r51",
      "r93",
      "r166",
      "r285",
      "r290",
      "r305"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 5.0,
       "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetsCurrentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Assets, Current [Abstract]",
        "terseLabel": "Current assets:"
       }
      }
     },
     "localname": "AssetsCurrentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesAmortizedCost": {
     "auth_ref": [],
     "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",
        "terseLabel": "Available for sale securities, Amortized Cost"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesAmortizedCost",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesCurrent": {
     "auth_ref": [],
     "calculation": {
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfClassificationOfAvailableForSaleSecuritiesOnConsolidatedBalanceSheetsDetail": {
       "order": 2.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesDebtSecurities",
       "weight": 1.0
      },
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 7.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer.",
        "label": "Available-for-sale Securities, Current",
        "terseLabel": "Short-term marketable securities"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfClassificationOfAvailableForSaleSecuritiesOnConsolidatedBalanceSheetsDetail",
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtSecurities": {
     "auth_ref": [
      "r153",
      "r155",
      "r178",
      "r377"
     ],
     "calculation": {
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfClassificationOfAvailableForSaleSecuritiesOnConsolidatedBalanceSheetsDetail": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities, Available-for-sale",
        "terseLabel": "Available for sale securities, Estimated Fair Value",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtSecurities",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail",
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfClassificationOfAvailableForSaleSecuritiesOnConsolidatedBalanceSheetsDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains": {
     "auth_ref": [
      "r156"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of unrealized gain before deducting unrealized loss on investments in debt and equity securities classified as available-for-sale securities.",
        "label": "Available-for-sale Securities, Gross Unrealized Gain",
        "terseLabel": "Available for sale securities, Unrealized Gains"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesGrossUnrealizedGains",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities.",
        "label": "Available-for-sale Securities [Table Text Block]",
        "terseLabel": "Summary of Available-for-Sale Securities"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_AwardTypeAxis": {
     "auth_ref": [
      "r233",
      "r262"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfShareBasedCompensationArrangementsByShareBasedPaymentAwardDetail",
      "http://www.gbt.com/role/StockBasedCompensationTables",
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail",
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsOfMarketConditionAwardsDetail"
     ],
     "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": "Basis of Preparation and Presentation of Financial Information"
       }
      }
     },
     "localname": "BasisOfAccountingPolicyPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_CashAndCashEquivalentsAtCarryingValue": {
     "auth_ref": [
      "r2",
      "r31",
      "r85"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 6.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      },
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue",
       "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"
       }
      }
     },
     "localname": "CashAndCashEquivalentsAtCarryingValue",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets",
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashAndCashEquivalentsAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of cash and cash equivalent balance.",
        "label": "Cash and Cash Equivalents [Axis]",
        "terseLabel": "Cash and Cash Equivalents [Axis]"
       }
      }
     },
     "localname": "CashAndCashEquivalentsAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "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": "Financial assets, fair value"
       }
      }
     },
     "localname": "CashAndCashEquivalentsFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents": {
     "auth_ref": [
      "r79",
      "r85",
      "r90"
     ],
     "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 at end of period",
        "periodStartLabel": "Cash, cash equivalents and restricted cash at beginning of period"
       }
      }
     },
     "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]",
        "terseLabel": "RECONCILIATION OF CASH, CASH EQUIVALENTS, AND RESTRICTED CASH TO THE CONDENSED CONSOLIDATED BALANCE SHEETS"
       }
      }
     },
     "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect": {
     "auth_ref": [
      "r79",
      "r306"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in cash, cash equivalents, and cash and cash equivalents restricted to withdrawal or usage; including 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), Including Exchange Rate Effect",
        "totalLabel": "Net (decrease) increase in cash, cash equivalents and restricted cash"
       }
      }
     },
     "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashEquivalentsAtCarryingValue": {
     "auth_ref": [
      "r31"
     ],
     "calculation": {
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfClassificationOfAvailableForSaleSecuritiesOnConsolidatedBalanceSheetsDetail": {
       "order": 1.0,
       "parentTag": "us-gaap_AvailableForSaleSecuritiesDebtSecurities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of 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 Equivalents, at Carrying Value",
        "terseLabel": "Cash and cash equivalents"
       }
      }
     },
     "localname": "CashEquivalentsAtCarryingValue",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfClassificationOfAvailableForSaleSecuritiesOnConsolidatedBalanceSheetsDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CertificatesOfDepositMember": {
     "auth_ref": [
      "r387"
     ],
     "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 Deposits [Member]"
       }
      }
     },
     "localname": "CertificatesOfDepositMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail",
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ClassOfStockLineItems": {
     "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": "Class of Stock [Line Items]",
        "terseLabel": "Class of Stock [Line Items]"
       }
      }
     },
     "localname": "ClassOfStockLineItems",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/OrganizationAndBasisOfPresentationAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CommitmentsAndContingencies": {
     "auth_ref": [
      "r44",
      "r196",
      "r378",
      "r396"
     ],
     "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"
       }
      }
     },
     "localname": "CommitmentsAndContingencies",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CommitmentsAndContingenciesDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Commitments and Contingencies Disclosure [Abstract]"
       }
      }
     },
     "localname": "CommitmentsAndContingenciesDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_CommitmentsAndContingenciesDisclosureTextBlock": {
     "auth_ref": [
      "r193",
      "r194",
      "r195",
      "r197"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for commitments and contingencies.",
        "label": "Commitments and Contingencies Disclosure [Text Block]",
        "terseLabel": "Commitments and Contingencies"
       }
      }
     },
     "localname": "CommitmentsAndContingenciesDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingencies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_CommonStockMember": {
     "auth_ref": [
      "r96",
      "r97"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Stock that is subordinate to all other stock of the issuer.",
        "label": "Common Stock [Member]",
        "terseLabel": "Common Stock [Member]"
       }
      }
     },
     "localname": "CommonStockMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommonStockParOrStatedValuePerShare": {
     "auth_ref": [
      "r17"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Face amount or stated value per share of common stock.",
        "label": "Common Stock, Par or Stated Value Per Share",
        "terseLabel": "Common stock, par value"
       }
      }
     },
     "localname": "CommonStockParOrStatedValuePerShare",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_CommonStockSharesAuthorized": {
     "auth_ref": [
      "r17"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockSharesIssued": {
     "auth_ref": [
      "r17"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockSharesOutstanding": {
     "auth_ref": [
      "r17",
      "r208"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.",
        "label": "Common Stock, Shares, Outstanding",
        "terseLabel": "Common stock, shares outstanding"
       }
      }
     },
     "localname": "CommonStockSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockValue": {
     "auth_ref": [
      "r17"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 22.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity.",
        "label": "Common Stock, Value, Issued",
        "terseLabel": "Common stock, $0.001 par value, 150,000,000 shares authorized as of June 30, 2021 (unaudited) and December 31, 2020, respectively; 62,379,118 and 61,898,090 shares issued and outstanding as of June 30, 2021 (unaudited) and December 31, 2020, respectively"
       }
      }
     },
     "localname": "CommonStockValue",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ComprehensiveIncomeNetOfTax": {
     "auth_ref": [
      "r63",
      "r65",
      "r66",
      "r68",
      "r380",
      "r398"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.",
        "label": "Comprehensive Income (Loss), Net of Tax, Attributable to Parent",
        "totalLabel": "Comprehensive loss"
       }
      }
     },
     "localname": "ComprehensiveIncomeNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ComputerEquipmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Long lived, depreciable assets that are used in the creation, maintenance and utilization of information systems.",
        "label": "Computer Equipment [Member]",
        "terseLabel": "Computer Equipment [Member]"
       }
      }
     },
     "localname": "ComputerEquipmentMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ConcentrationRiskBenchmarkDomain": {
     "auth_ref": [
      "r129",
      "r130",
      "r150",
      "r303",
      "r304"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The denominator in a calculation of a disclosed concentration risk percentage.",
        "label": "Concentration Risk Benchmark [Domain]"
       }
      }
     },
     "localname": "ConcentrationRiskBenchmarkDomain",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ConcentrationRiskByBenchmarkAxis": {
     "auth_ref": [
      "r129",
      "r130",
      "r150",
      "r303",
      "r304",
      "r415"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by benchmark of concentration risk.",
        "label": "Concentration Risk Benchmark [Axis]"
       }
      }
     },
     "localname": "ConcentrationRiskByBenchmarkAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ConcentrationRiskByTypeAxis": {
     "auth_ref": [
      "r129",
      "r130",
      "r150",
      "r303",
      "r304",
      "r415"
     ],
     "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]"
       }
      }
     },
     "localname": "ConcentrationRiskByTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ConcentrationRiskPercentage1": {
     "auth_ref": [
      "r129",
      "r130",
      "r150",
      "r303",
      "r304"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_ConcentrationRiskTypeDomain": {
     "auth_ref": [
      "r129",
      "r130",
      "r150",
      "r303",
      "r304"
     ],
     "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]"
       }
      }
     },
     "localname": "ConcentrationRiskTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ConsolidationPolicyTextBlock": {
     "auth_ref": [
      "r91",
      "r287"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of accounting policy regarding (1) the principles it follows in consolidating or combining the separate financial statements, including the principles followed in determining the inclusion or exclusion of subsidiaries or other entities in the consolidated or combined financial statements and (2) its treatment of interests (for example, common stock, a partnership interest or other means of exerting influence) in other entities, for example consolidation or use of the equity or cost methods of accounting.  The accounting policy may also address the accounting treatment for intercompany accounts and transactions, noncontrolling interest, and the income statement treatment in consolidation for issuances of stock by a subsidiary.",
        "label": "Consolidation, Policy [Policy Text Block]",
        "terseLabel": "Principles of Consolidation"
       }
      }
     },
     "localname": "ConsolidationPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ConstructionInProgressMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.",
        "label": "Construction in Progress [Member]",
        "terseLabel": "Construction-in-Progress [Member]"
       }
      }
     },
     "localname": "ConstructionInProgressMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ContractualObligationFiscalYearMaturityScheduleAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Contractual Obligation, Fiscal Year Maturity Schedule [Abstract]"
       }
      }
     },
     "localname": "ContractualObligationFiscalYearMaturityScheduleAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_ConversionOfStockByUniqueDescriptionAxis": {
     "auth_ref": [
      "r87",
      "r88",
      "r89"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by description of stock conversions.",
        "label": "Stock Conversion Description [Axis]",
        "terseLabel": "Stock Conversion Description [Axis]"
       }
      }
     },
     "localname": "ConversionOfStockByUniqueDescriptionAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/OrganizationAndBasisOfPresentationAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ConversionOfStockNameDomain": {
     "auth_ref": [
      "r87",
      "r88",
      "r89"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The unique name of a noncash or part noncash stock conversion.",
        "label": "Conversion of Stock, Name [Domain]",
        "terseLabel": "Conversion of Stock, Name [Domain]"
       }
      }
     },
     "localname": "ConversionOfStockNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/OrganizationAndBasisOfPresentationAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CorporateDebtSecuritiesMember": {
     "auth_ref": [
      "r220",
      "r227",
      "r414"
     ],
     "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 Debt Securities [Member]"
       }
      }
     },
     "localname": "CorporateDebtSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail",
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CostOfGoodsAndServicesSold": {
     "auth_ref": [
      "r71",
      "r366"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 6.0,
       "parentTag": "us-gaap_CostsAndExpenses",
       "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",
        "verboseLabel": "Cost of sales"
       }
      }
     },
     "localname": "CostOfGoodsAndServicesSold",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CostsAndExpenses": {
     "auth_ref": [
      "r70"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 4.0,
       "parentTag": "us-gaap_OperatingIncomeLoss",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total costs of sales and operating expenses for the period.",
        "label": "Costs and Expenses",
        "totalLabel": "Total costs and operating expenses"
       }
      }
     },
     "localname": "CostsAndExpenses",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CostsAndExpensesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Costs and Expenses [Abstract]",
        "terseLabel": "Costs and operating expenses:"
       }
      }
     },
     "localname": "CostsAndExpensesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "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]"
       }
      }
     },
     "localname": "CreditFacilityAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "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]"
       }
      }
     },
     "localname": "CreditFacilityDomain",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CustomerConcentrationRiskMember": {
     "auth_ref": [
      "r127",
      "r150"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Reflects the percentage that revenues in the period from one or more significant customers is to net revenues, as defined by the entity, such as total net revenues, product line revenues, segment revenues. The risk is the materially adverse effects of loss of a significant customer.",
        "label": "Customer Concentration Risk [Member]",
        "terseLabel": "Customer Concentration Risk [Member]"
       }
      }
     },
     "localname": "CustomerConcentrationRiskMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_DebtDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Debt Disclosure [Abstract]"
       }
      }
     },
     "localname": "DebtDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_DebtDisclosureTextBlock": {
     "auth_ref": [
      "r204"
     ],
     "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": "Long-term Debt"
       }
      }
     },
     "localname": "DebtDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebt"
     ],
     "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": "Debt Instrument, Basis Spread on Variable Rate"
       }
      }
     },
     "localname": "DebtInstrumentBasisSpreadOnVariableRate1",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_DebtInstrumentCarryingAmount": {
     "auth_ref": [
      "r15",
      "r200",
      "r375",
      "r388"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.",
        "label": "Long-term Debt, Gross",
        "terseLabel": "Long-term debt, gross"
       }
      }
     },
     "localname": "DebtInstrumentCarryingAmount",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtInstrumentFeeAmount": {
     "auth_ref": [
      "r41"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of the fee that accompanies borrowing money under the debt instrument.",
        "label": "Debt Instrument, Fee Amount",
        "terseLabel": "Debt additional paydown fee"
       }
      }
     },
     "localname": "DebtInstrumentFeeAmount",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtInstrumentTerm": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Debt Instrument, Term"
       }
      }
     },
     "localname": "DebtInstrumentTerm",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_DebtInstrumentUnamortizedDiscount": {
     "auth_ref": [
      "r314",
      "r316"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after accumulated amortization, of debt discount.",
        "label": "Debt Instrument, Unamortized Discount",
        "verboseLabel": "Unamortized dedt discount"
       }
      }
     },
     "localname": "DebtInstrumentUnamortizedDiscount",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet": {
     "auth_ref": [
      "r201",
      "r315"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of unamortized debt discount (premium) and debt issuance costs.",
        "label": "Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net",
        "terseLabel": "Unamortized issuance costs and debt discounts"
       }
      }
     },
     "localname": "DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_Depreciation": {
     "auth_ref": [
      "r83",
      "r188"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.",
        "label": "Depreciation",
        "terseLabel": "Depreciation expense"
       }
      }
     },
     "localname": "Depreciation",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DepreciationDepletionAndAmortization": {
     "auth_ref": [
      "r83",
      "r136"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 21.0,
       "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock": {
     "auth_ref": [
      "r275"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for share-based payment arrangement.",
        "label": "Disclosure of Compensation Related Costs, Share-based Payments [Text Block]",
        "verboseLabel": "Stock-Based Compensation"
       }
      }
     },
     "localname": "DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensation"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Disclosure of Compensation Related Costs, Share-based Payments [Abstract]"
       }
      }
     },
     "localname": "DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock": {
     "auth_ref": [
      "r233",
      "r262"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of share-based payment arrangement.",
        "label": "Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]",
        "terseLabel": "Summary of Share-based Compensation Arrangements by Share-based Payment Award"
       }
      }
     },
     "localname": "DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DisclosureTextBlockAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Disclosure Text Block [Abstract]"
       }
      }
     },
     "localname": "DisclosureTextBlockAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_EarningsPerShareAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Earnings Per Share [Abstract]"
       }
      }
     },
     "localname": "EarningsPerShareAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_EarningsPerShareBasicAndDiluted": {
     "auth_ref": [
      "r114"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements.  Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period.  Diluted earnings per share includes the amount of net income or 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, Basic and Diluted",
        "terseLabel": "Basic and diluted net loss per common share"
       }
      }
     },
     "localname": "EarningsPerShareBasicAndDiluted",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_EarningsPerShareTextBlock": {
     "auth_ref": [
      "r115",
      "r116",
      "r117",
      "r119"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for earnings per share.",
        "label": "Earnings Per Share [Text Block]",
        "terseLabel": "Net Loss per Share"
       }
      }
     },
     "localname": "EarningsPerShareTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/NetLossPerShare"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents": {
     "auth_ref": [
      "r306"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 11.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) from effect of exchange rate changes on cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage; held in foreign currencies. Excludes amounts 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": "Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents",
        "terseLabel": "Effect of exchange rate changes on cash and cash equivalents"
       }
      }
     },
     "localname": "EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeRelatedLiabilitiesCurrent": {
     "auth_ref": [
      "r38"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 18.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "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": "Accrued compensation"
       }
      }
     },
     "localname": "EmployeeRelatedLiabilitiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount": {
     "auth_ref": [
      "r260"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cost capitalized for award under share-based payment arrangement.",
        "label": "Share-based Payment Arrangement, Amount Capitalized",
        "terseLabel": "Share based compensation expense capitalized"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems": {
     "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, Compensation Cost [Line Items]",
        "terseLabel": "Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationStockBasedCompensationExpenseRecognizedDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized": {
     "auth_ref": [
      "r261"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cost not yet recognized for nonvested award under share-based payment arrangement.",
        "label": "Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized",
        "terseLabel": "Unrecognized compensation expense"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1": {
     "auth_ref": [
      "r261"
     ],
     "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": "Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition",
        "terseLabel": "Weighted average derived service period"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_EmployeeStockOptionMember": {
     "auth_ref": [
      "r257"
     ],
     "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": "Employee Stock Option [Member]",
        "terseLabel": "Stock Options [Member]"
       }
      }
     },
     "localname": "EmployeeStockOptionMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/NetLossPerSharePotentiallyDilutiveSecuritiesThatWereNotIncludedInDilutedNetLossPerShareCalculationsDetail",
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_EquipmentMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tangible personal property used to produce goods and services.",
        "label": "Equipment [Member]",
        "terseLabel": "Laboratory Equipment [Member]"
       }
      }
     },
     "localname": "EquipmentMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_EquityComponentDomain": {
     "auth_ref": [
      "r96",
      "r97",
      "r99",
      "r101",
      "r109",
      "r112",
      "r120",
      "r170",
      "r208",
      "r215",
      "r267",
      "r268",
      "r269",
      "r279",
      "r280",
      "r307",
      "r308",
      "r309",
      "r310",
      "r311",
      "r312",
      "r404",
      "r405",
      "r406"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity",
      "http://www.gbt.com/role/OrganizationAndBasisOfPresentationAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]",
        "terseLabel": "Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable": {
     "auth_ref": [
      "r293",
      "r294",
      "r295",
      "r300"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about asset and liability measured at fair value on recurring and nonrecurring basis.",
        "label": "Fair Value Measurements, Recurring and Nonrecurring [Table]",
        "terseLabel": "Fair Value Measurements, Recurring and Nonrecurring [Table]"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain": {
     "auth_ref": [
      "r298"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Class of asset.",
        "label": "Asset Class [Domain]",
        "terseLabel": "Asset Class [Domain]"
       }
      }
     },
     "localname": "FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueByAssetClassAxis": {
     "auth_ref": [
      "r293",
      "r300"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByBalanceSheetGroupingTextBlock": {
     "auth_ref": [
      "r293",
      "r302"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the fair value of financial instruments, including financial assets and financial liabilities, and the measurements of those instruments, assets, and liabilities.",
        "label": "Fair Value, by Balance Sheet Grouping [Table Text Block]",
        "terseLabel": "Fair Value, Assets Measured on Recurring Basis"
       }
      }
     },
     "localname": "FairValueByBalanceSheetGroupingTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/FairValueMeasurementsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueByFairValueHierarchyLevelAxis": {
     "auth_ref": [
      "r220",
      "r221",
      "r222",
      "r223",
      "r224",
      "r225",
      "r226",
      "r227",
      "r294",
      "r338",
      "r339",
      "r340"
     ],
     "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 [Axis]"
       }
      }
     },
     "localname": "FairValueByFairValueHierarchyLevelAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByMeasurementFrequencyAxis": {
     "auth_ref": [
      "r293",
      "r294",
      "r296",
      "r297",
      "r301"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Fair Value Disclosures [Abstract]"
       }
      }
     },
     "localname": "FairValueDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueDisclosuresTextBlock": {
     "auth_ref": [
      "r299"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.",
        "label": "Fair Value Disclosures [Text Block]",
        "terseLabel": "Fair Value Measurements"
       }
      }
     },
     "localname": "FairValueDisclosuresTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/FairValueMeasurements"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueInputsLevel1Member": {
     "auth_ref": [
      "r220",
      "r221",
      "r226",
      "r227",
      "r294",
      "r338"
     ],
     "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": "Level 1 [Member]"
       }
      }
     },
     "localname": "FairValueInputsLevel1Member",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueInputsLevel2Member": {
     "auth_ref": [
      "r220",
      "r221",
      "r226",
      "r227",
      "r294",
      "r339"
     ],
     "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": "Level 2 [Member]"
       }
      }
     },
     "localname": "FairValueInputsLevel2Member",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueMeasurementFrequencyDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Measurement frequency.",
        "label": "Fair Value, Measurement Frequency [Domain]",
        "terseLabel": "Fair Value, Measurement Frequency [Domain]"
       }
      }
     },
     "localname": "FairValueMeasurementFrequencyDomain",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueMeasurementsFairValueHierarchyDomain": {
     "auth_ref": [
      "r220",
      "r221",
      "r222",
      "r223",
      "r224",
      "r225",
      "r226",
      "r227",
      "r338",
      "r339",
      "r340"
     ],
     "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 Hierarchy [Domain]"
       }
      }
     },
     "localname": "FairValueMeasurementsFairValueHierarchyDomain",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueMeasurementsRecurringMember": {
     "auth_ref": [
      "r299",
      "r301"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Frequent fair value measurement. Includes, but is not limited to, fair value adjustment for impairment of asset, liability or equity, frequently measured at fair value.",
        "label": "Fair Value, Measurements, Recurring [Member]",
        "terseLabel": "Fair Value Measurements, Recurring [Member]"
       }
      }
     },
     "localname": "FairValueMeasurementsRecurringMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FinancialInstrumentAxis": {
     "auth_ref": [
      "r159",
      "r160",
      "r173",
      "r174",
      "r175",
      "r176",
      "r177",
      "r179",
      "r180",
      "r181",
      "r182",
      "r335",
      "r336",
      "r337",
      "r338",
      "r339",
      "r340",
      "r341",
      "r342",
      "r343",
      "r344",
      "r345",
      "r346",
      "r347",
      "r348",
      "r349",
      "r350",
      "r351",
      "r352",
      "r353",
      "r354",
      "r355",
      "r356",
      "r357",
      "r358",
      "r359",
      "r360",
      "r361",
      "r362",
      "r363",
      "r364"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of financial instrument.",
        "label": "Financial Instrument [Axis]"
       }
      }
     },
     "localname": "FinancialInstrumentAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancialSupportToNonconsolidatedLegalEntityAxis": {
     "auth_ref": [
      "r282",
      "r416"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by financial support arrangement provided to a nonconsolidated legal entity that is required to comply with or operate in accordance with requirements that are similar to those included in Rule 2a-7 of the Investment Company Act of 1940 for registered money market funds.",
        "label": "Financial Support to Nonconsolidated Legal Entity [Axis]",
        "terseLabel": "Financial Support to Nonconsolidated Legal Entity [Axis]"
       }
      }
     },
     "localname": "FinancialSupportToNonconsolidatedLegalEntityAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain": {
     "auth_ref": [
      "r282",
      "r416"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Financial support arrangement provided to a nonconsolidated legal entity that is required to comply with or operate in accordance with requirements that are similar to those included in Rule 2a-7 of the Investment Company Act of 1940 for registered money market funds.",
        "label": "Financial Support to Nonconsolidated Legal Entity [Domain]",
        "terseLabel": "Financial Support to Nonconsolidated Legal Entity [Domain]"
       }
      }
     },
     "localname": "FinancialSupportToNonconsolidatedLegalEntityDomain",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis": {
     "auth_ref": [
      "r183",
      "r184",
      "r186",
      "r187",
      "r367",
      "r371"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain": {
     "auth_ref": [
      "r183",
      "r185"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_IncomeStatementAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Income Statement [Abstract]"
       }
      }
     },
     "localname": "IncomeStatementAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeStatementLocationAxis": {
     "auth_ref": [
      "r192"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationStockBasedCompensationExpenseRecognizedDetail"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationStockBasedCompensationExpenseRecognizedDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_IncreaseDecreaseInAccountsPayableTrade": {
     "auth_ref": [
      "r82"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 14.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Change in recurring obligations of a business that arise from the acquisition of merchandise, materials, supplies and services used in the production and sale of goods and services.",
        "label": "Increase (Decrease) in Accounts Payable, Trade",
        "terseLabel": "Accounts payable"
       }
      }
     },
     "localname": "IncreaseDecreaseInAccountsPayableTrade",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInAccountsReceivable": {
     "auth_ref": [
      "r82"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 19.0,
       "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities": {
     "auth_ref": [
      "r82"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 16.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in the aggregate amount of obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits.",
        "label": "Increase (Decrease) in Employee Related Liabilities",
        "terseLabel": "Accrued compensation"
       }
      }
     },
     "localname": "IncreaseDecreaseInEmployeeRelatedLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInInventories": {
     "auth_ref": [
      "r82"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 20.0,
       "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "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:"
       }
      }
     },
     "localname": "IncreaseDecreaseInOperatingCapitalAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncreaseDecreaseInOtherAccruedLiabilities": {
     "auth_ref": [
      "r82"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 15.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in other expenses incurred but not yet paid.",
        "label": "Increase (Decrease) in Other Accrued Liabilities",
        "terseLabel": "Accrued liabilities"
       }
      }
     },
     "localname": "IncreaseDecreaseInOtherAccruedLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInOtherOperatingLiabilities": {
     "auth_ref": [
      "r82"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 18.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in operating liabilities classified as other.",
        "label": "Increase (Decrease) in Other Operating Liabilities",
        "verboseLabel": "Other liabilities"
       }
      }
     },
     "localname": "IncreaseDecreaseInOtherOperatingLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets": {
     "auth_ref": [
      "r82"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 13.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of increase (decrease) in prepaid expenses, and assets classified as other.",
        "label": "Increase (Decrease) in Prepaid Expense and Other Assets",
        "negatedLabel": "Prepaid expenses and other assets"
       }
      }
     },
     "localname": "IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestExpenseDebt": {
     "auth_ref": [
      "r73",
      "r203"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of the cost of borrowed funds accounted for as interest expense for debt.",
        "label": "Interest Expense, Debt",
        "negatedLabel": "Less amount representing interest"
       }
      }
     },
     "localname": "InterestExpenseDebt",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InterestPaidNet": {
     "auth_ref": [
      "r78",
      "r80",
      "r86"
     ],
     "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"
       }
      }
     },
     "localname": "InterestPaidNet",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InventoryFinishedGoods": {
     "auth_ref": [
      "r47"
     ],
     "calculation": {
      "http://www.gbt.com/role/BalanceSheetComponentsInventoriesDetail": {
       "order": 3.0,
       "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"
       }
      }
     },
     "localname": "InventoryFinishedGoods",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsInventoriesDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InventoryNet": {
     "auth_ref": [
      "r3",
      "r50"
     ],
     "calculation": {
      "http://www.gbt.com/role/BalanceSheetComponentsInventoriesDetail": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 9.0,
       "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": "Total inventories"
       }
      }
     },
     "localname": "InventoryNet",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsInventoriesDetail",
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InventoryRawMaterials": {
     "auth_ref": [
      "r49"
     ],
     "calculation": {
      "http://www.gbt.com/role/BalanceSheetComponentsInventoriesDetail": {
       "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"
       }
      }
     },
     "localname": "InventoryRawMaterials",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsInventoriesDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InventoryWorkInProcess": {
     "auth_ref": [
      "r48"
     ],
     "calculation": {
      "http://www.gbt.com/role/BalanceSheetComponentsInventoriesDetail": {
       "order": 2.0,
       "parentTag": "us-gaap_InventoryNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount before valuation and LIFO reserves of merchandise or goods in the production process expected to be completed within one year or operating cycle, if longer.",
        "label": "Inventory, Work in Process, Gross",
        "terseLabel": "Work-in-process"
       }
      }
     },
     "localname": "InventoryWorkInProcess",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsInventoriesDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Investments, Debt and Equity Securities [Abstract]"
       }
      }
     },
     "localname": "InvestmentsDebtAndEquitySecuritiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_InvestmentsFairValueDisclosure": {
     "auth_ref": [
      "r293"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.",
        "label": "Investments, Fair Value Disclosure",
        "terseLabel": "Financial assets, fair value"
       }
      }
     },
     "localname": "InvestmentsFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock": {
     "auth_ref": [
      "r165",
      "r373",
      "r386",
      "r418"
     ],
     "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": "Available-for-Sale Securities"
       }
      }
     },
     "localname": "InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecurities"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LeaseAgreementsMember": {
     "auth_ref": [
      "r281"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Contractual agreement that stipulates the lessee pay the lessor for use of an asset.",
        "label": "Lease Agreements [Member]",
        "terseLabel": "Lease Agreements [Member]"
       }
      }
     },
     "localname": "LeaseAgreementsMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LeaseContractualTermAxis": {
     "auth_ref": [
      "r324"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by contractual term of lease arrangement.",
        "label": "Lease Contractual Term [Axis]"
       }
      }
     },
     "localname": "LeaseContractualTermAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LeaseContractualTermDomain": {
     "auth_ref": [
      "r324"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Contractual term of lease arrangement.",
        "label": "Lease Contractual Term [Domain]"
       }
      }
     },
     "localname": "LeaseContractualTermDomain",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LeaseholdImprovementsMember": {
     "auth_ref": [
      "r189"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Additions or improvements to assets held under a lease arrangement.",
        "label": "Leasehold Improvements [Member]",
        "terseLabel": "Leasehold Improvements [Member]"
       }
      }
     },
     "localname": "LeaseholdImprovementsMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail",
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock": {
     "auth_ref": [
      "r331"
     ],
     "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]",
        "verboseLabel": "Schedule of Lessee, Operating Lease, Liability, Maturity"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityMaturityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue": {
     "auth_ref": [
      "r331"
     ],
     "calculation": {
      "http://www.gbt.com/role/CommitmentsAndContingenciesLesseeOperatingLeaseLiabilityMaturityDetail": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease.",
        "label": "Lessee, Operating Lease, Liability, Payments, Due",
        "totalLabel": "Total lease payments"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDue",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesLesseeOperatingLeaseLiabilityMaturityDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths": {
     "auth_ref": [
      "r331"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Lessee, Operating Lease, Liability, to be Paid, Year One",
        "terseLabel": "2022"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesLesseeOperatingLeaseLiabilityMaturityDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour": {
     "auth_ref": [
      "r331"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Lessee, Operating Lease, Liability, Payments, Due Year Four",
        "verboseLabel": "2025"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearFour",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesLesseeOperatingLeaseLiabilityMaturityDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree": {
     "auth_ref": [
      "r331"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Lessee, Operating Lease, Liability, Payments, Due Year Three",
        "terseLabel": "2024"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearThree",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesLesseeOperatingLeaseLiabilityMaturityDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo": {
     "auth_ref": [
      "r331"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).",
        "label": "Lessee, Operating Lease, Liability, Payments, Due Year Two",
        "terseLabel": "2023"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDueYearTwo",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesLesseeOperatingLeaseLiabilityMaturityDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear": {
     "auth_ref": [
      "r331"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payment for operating lease having initial or remaining lease term in excess of one year to be paid in remainder of current fiscal year.",
        "label": "Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year",
        "terseLabel": "2021 (six months)"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesLesseeOperatingLeaseLiabilityMaturityDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount": {
     "auth_ref": [
      "r331"
     ],
     "calculation": {
      "http://www.gbt.com/role/CommitmentsAndContingenciesLesseeOperatingLeaseLiabilityMaturityDetail": {
       "order": 1.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating lease.",
        "label": "Lessee, Operating Lease, Liability, Undiscounted Excess Amount",
        "negatedLabel": "Less: Imputed interest"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityUndiscountedExcessAmount",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesLesseeOperatingLeaseLiabilityMaturityDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseTermOfContract": {
     "auth_ref": [
      "r323"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.",
        "label": "Lessee, Operating Lease, Term of Contract",
        "terseLabel": "Initial term"
       }
      }
     },
     "localname": "LesseeOperatingLeaseTermOfContract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_Liabilities": {
     "auth_ref": [
      "r37",
      "r93",
      "r141",
      "r166",
      "r286",
      "r290",
      "r291",
      "r305"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 11.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.",
        "label": "Liabilities",
        "totalLabel": "Total liabilities"
       }
      }
     },
     "localname": "Liabilities",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesAndStockholdersEquity": {
     "auth_ref": [
      "r24",
      "r93",
      "r166",
      "r305",
      "r376",
      "r393"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of liabilities and equity items, including the portion of equity attributable to noncontrolling interests, if any.",
        "label": "Liabilities and Equity",
        "totalLabel": "Total liabilities and stockholders' equity"
       }
      }
     },
     "localname": "LiabilitiesAndStockholdersEquity",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesAndStockholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Liabilities and Equity [Abstract]",
        "terseLabel": "Liabilities and Stockholders' Equity"
       }
      }
     },
     "localname": "LiabilitiesAndStockholdersEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LiabilitiesCurrent": {
     "auth_ref": [
      "r39",
      "r93",
      "r166",
      "r286",
      "r290",
      "r291",
      "r305"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 15.0,
       "parentTag": "us-gaap_Liabilities",
       "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesCurrentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Liabilities, Current [Abstract]",
        "terseLabel": "Current liabilities:"
       }
      }
     },
     "localname": "LiabilitiesCurrentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity": {
     "auth_ref": [
      "r36"
     ],
     "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": "Debt maximum borrowing capacity"
       }
      }
     },
     "localname": "LineOfCreditFacilityMaximumBorrowingCapacity",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebt": {
     "auth_ref": [
      "r15",
      "r202",
      "r375",
      "r390"
     ],
     "calculation": {
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail": {
       "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",
        "totalLabel": "Total minimum payments"
       }
      }
     },
     "localname": "LongTermDebt",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtNoncurrent": {
     "auth_ref": [
      "r42"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 14.0,
       "parentTag": "us-gaap_Liabilities",
       "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",
        "verboseLabel": "Long term debt"
       }
      }
     },
     "localname": "LongTermDebtNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets",
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail",
      "http://www.gbt.com/role/LongTermDebtScheduleOfFuturePaymentsOfPrincipalAndInterestOnTheTermLoanDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LongTermDebtPercentageBearingVariableInterestRate": {
     "auth_ref": [
      "r40"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time.",
        "label": "Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate",
        "terseLabel": "Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate"
       }
      }
     },
     "localname": "LongTermDebtPercentageBearingVariableInterestRate",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_LongtermDebtTypeAxis": {
     "auth_ref": [
      "r42"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of long-term debt.",
        "label": "Long-term Debt, Type [Axis]",
        "terseLabel": "Long-term Debt, Type [Axis]"
       }
      }
     },
     "localname": "LongtermDebtTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail",
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LongtermDebtTypeDomain": {
     "auth_ref": [
      "r42",
      "r199"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Type of long-term debt arrangement, such as notes, line of credit, commercial paper, asset-based financing, project financing, letter of credit financing. 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": "Long-term Debt, Type [Domain]",
        "terseLabel": "Long-term Debt, Type [Domain]"
       }
      }
     },
     "localname": "LongtermDebtTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail",
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LossContingencyAccrualProvision": {
     "auth_ref": [
      "r196"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount charged against operating income increasing loss contingency liability, after adjustments to reduce previously estimated charges.",
        "label": "Provisions for loss contingency"
       }
      }
     },
     "localname": "LossContingencyAccrualProvision",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LossContingencyLossInPeriod": {
     "auth_ref": [
      "r196"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The amount of loss pertaining to the specified contingency that was charged against earnings in the period, including the effects of revisions in previously reported estimates.",
        "label": "Contingency losses"
       }
      }
     },
     "localname": "LossContingencyLossInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_MarketableSecuritiesUnrealizedGainLoss": {
     "auth_ref": [
      "r69"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of unrealized gain (loss) on investment in marketable security.",
        "label": "Marketable Securities, Unrealized Gain (Loss)",
        "terseLabel": "Net unrealized gain (loss) on marketable securities"
       }
      }
     },
     "localname": "MarketableSecuritiesUnrealizedGainLoss",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_MoneyMarketFundsMember": {
     "auth_ref": [
      "r220"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Fund that invests in short-term money-market instruments, for example, but not limited to, commercial paper, banker's acceptances, repurchase agreements, government securities, certificates of deposit, and other highly liquid securities.",
        "label": "Money Market Funds [Member]",
        "terseLabel": "Money Market Funds [Member]"
       }
      }
     },
     "localname": "MoneyMarketFundsMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail",
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_NetCashProvidedByUsedInFinancingActivities": {
     "auth_ref": [
      "r79"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 7.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect",
       "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 financing activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInFinancingActivities",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Net Cash Provided by (Used in) Financing Activities [Abstract]",
        "terseLabel": "CASH FLOWS FROM FINANCING ACTIVITIES:"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInFinancingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetCashProvidedByUsedInInvestingActivities": {
     "auth_ref": [
      "r79"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect",
       "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 provided by investing activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInInvestingActivities",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Net Cash Provided by (Used in) Investing Activities [Abstract]",
        "terseLabel": "CASH FLOWS FROM INVESTING ACTIVITIES:"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInInvestingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetCashProvidedByUsedInOperatingActivities": {
     "auth_ref": [
      "r79",
      "r81",
      "r84"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 12.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect",
       "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 used in operating activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInOperatingActivities",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Net Cash Provided by (Used in) Operating Activities [Abstract]",
        "terseLabel": "CASH FLOWS FROM OPERATING ACTIVITIES:"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInOperatingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetIncomeLoss": {
     "auth_ref": [
      "r0",
      "r61",
      "r64",
      "r67",
      "r84",
      "r93",
      "r100",
      "r104",
      "r105",
      "r106",
      "r107",
      "r111",
      "r112",
      "r113",
      "r137",
      "r139",
      "r142",
      "r145",
      "r147",
      "r166",
      "r305",
      "r379",
      "r397"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 26.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      },
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 1.0,
       "parentTag": "us-gaap_ComprehensiveIncomeNetOfTax",
       "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 loss",
        "totalLabel": "Net loss"
       }
      }
     },
     "localname": "NetIncomeLoss",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows",
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss",
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "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": "Accounting Pronouncements Adopted"
       }
      }
     },
     "localname": "NewAccountingPronouncementsPolicyPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_NoncashInvestingAndFinancingItemsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Noncash Investing and Financing Items [Abstract]",
        "terseLabel": "SUPPLEMENTAL DISCLOSURES OF NON-CASH\u00a0INVESTING AND FINANCING INFORMATION:"
       }
      }
     },
     "localname": "NoncashInvestingAndFinancingItemsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NoninterestExpense": {
     "auth_ref": [
      "r382"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 11.0,
       "parentTag": "us-gaap_OtherNonoperatingIncomeExpense",
       "weight": -1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total aggregate amount of all noninterest expense.",
        "label": "Noninterest Expense",
        "negatedLabel": "Interest expense"
       }
      }
     },
     "localname": "NoninterestExpense",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NoninterestIncome": {
     "auth_ref": [
      "r381"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 9.0,
       "parentTag": "us-gaap_OtherNonoperatingIncomeExpense",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The total amount of noninterest income which may be derived from: (1) fees and commissions; (2) premiums earned; (3) insurance policy charges; (4) the sale or disposal of assets; and (5) other sources not otherwise specified.",
        "label": "Noninterest Income",
        "terseLabel": "Interest income"
       }
      }
     },
     "localname": "NoninterestIncome",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock": {
     "auth_ref": [
      "r236"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of the changes in outstanding nonvested restricted stock shares.",
        "label": "Nonvested Restricted Stock Shares Activity [Table Text Block]",
        "terseLabel": "Non-Vested Restricted Stock Activity"
       }
      }
     },
     "localname": "NonvestedRestrictedStockSharesActivityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_OperatingExpensesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Operating Expenses [Abstract]",
        "terseLabel": "Other income (expense):"
       }
      }
     },
     "localname": "OperatingExpensesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OperatingIncomeLoss": {
     "auth_ref": [
      "r137",
      "r139",
      "r142",
      "r145",
      "r147"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 2.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "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": "Loss from operations"
       }
      }
     },
     "localname": "OperatingIncomeLoss",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseCost": {
     "auth_ref": [
      "r325",
      "r332"
     ],
     "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",
        "verboseLabel": "Operating Lease Cost"
       }
      }
     },
     "localname": "OperatingLeaseCost",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseLiability": {
     "auth_ref": [
      "r321"
     ],
     "calculation": {
      "http://www.gbt.com/role/CommitmentsAndContingenciesLesseeOperatingLeaseLiabilityMaturityDetail": {
       "order": 2.0,
       "parentTag": "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "definitionGuidance": "Present value of operating lease liabilities",
        "documentation": "Present value of lessee's discounted obligation for lease payments from operating lease.",
        "label": "Operating liabilities"
       }
      }
     },
     "localname": "OperatingLeaseLiability",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesLesseeOperatingLeaseLiabilityMaturityDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseLiabilityCurrent": {
     "auth_ref": [
      "r321"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 19.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseLiabilityNoncurrent": {
     "auth_ref": [
      "r321"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 12.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "definitionGuidance": "Operating lease liabilities, noncurrent",
        "documentation": "Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent.",
        "label": "Operating Lease, Liability, Noncurrent"
       }
      }
     },
     "localname": "OperatingLeaseLiabilityNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasePaymentsUse": {
     "auth_ref": [
      "r322",
      "r327"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "definitionGuidance": "Cash paid for amounts included in the measurement of lease liabilities",
        "documentation": "Amount of cash outflow from operating lease to bring another asset to condition and location necessary for its intended use.",
        "label": "Operating Lease, Payments, Use"
       }
      }
     },
     "localname": "OperatingLeasePaymentsUse",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesSupplementalCashFlowInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseRightOfUseAsset": {
     "auth_ref": [
      "r320"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "definitionGuidance": "Operating lease right-of-use assets",
        "documentation": "Amount of lessee's right to use underlying asset under operating lease.",
        "label": "Operating Lease Right Of Use Asset"
       }
      }
     },
     "localname": "OperatingLeaseRightOfUseAsset",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense": {
     "auth_ref": [
      "r83"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 24.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "definitionGuidance": "Amortization of operating lease right-of-use assets",
        "documentation": "Amount of amortization expense for right-of-use asset from operating lease.",
        "label": "Operating Lease, Right-of-Use Asset, Amortization Expense"
       }
      }
     },
     "localname": "OperatingLeaseRightOfUseAssetAmortizationExpense",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent": {
     "auth_ref": [
      "r330",
      "r332"
     ],
     "lang": {
      "en-us": {
       "role": {
        "definitionGuidance": "Weighted-average discount rate of operating leases",
        "documentation": "Weighted average discount rate for operating lease calculated at point in time.",
        "label": "Operating Lease, Weighted Average Discount Rate, Percent"
       }
      }
     },
     "localname": "OperatingLeaseWeightedAverageDiscountRatePercent",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesSupplementalCashFlowInformationDetail"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1": {
     "auth_ref": [
      "r329",
      "r332"
     ],
     "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 of operating leases (in years)"
       }
      }
     },
     "localname": "OperatingLeaseWeightedAverageRemainingLeaseTerm1",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesSupplementalCashFlowInformationDetail"
     ],
     "xbrltype": "durationItemType"
    },
    "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/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_OperatingLeasesIncomeStatementDepreciationExpenseOnPropertySubjectToOrHeldForLease": {
     "auth_ref": [
      "r188"
     ],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The total depreciation charge recorded for property subject to or held for lease.",
        "label": "Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease",
        "terseLabel": "Acceleration of depreciation expenses"
       }
      }
     },
     "localname": "OperatingLeasesIncomeStatementDepreciationExpenseOnPropertySubjectToOrHeldForLease",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Organization, Consolidation and Presentation of Financial Statements [Abstract]"
       }
      }
     },
     "localname": "OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock": {
     "auth_ref": [
      "r1",
      "r292"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The entire disclosure for organization, consolidation and basis of presentation of financial statements disclosure.",
        "label": "Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]",
        "verboseLabel": "Organization"
       }
      }
     },
     "localname": "OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/Organization"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_OtherAccruedLiabilitiesCurrent": {
     "auth_ref": [
      "r7",
      "r8",
      "r9",
      "r38"
     ],
     "calculation": {
      "http://www.gbt.com/role/BalanceSheetComponentsAccruedLiabilitiesDetail": {
       "order": 1.0,
       "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",
        "terseLabel": "Other"
       }
      }
     },
     "localname": "OtherAccruedLiabilitiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsAccruedLiabilitiesDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherAssetsNoncurrent": {
     "auth_ref": [
      "r34"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 4.0,
       "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, noncurrent"
       }
      }
     },
     "localname": "OtherAssetsNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax": {
     "auth_ref": [
      "r54"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 13.0,
       "parentTag": "us-gaap_ComprehensiveIncomeNetOfTax",
       "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",
        "terseLabel": "Cumulative translation adjustment"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss",
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent": {
     "auth_ref": [
      "r62",
      "r65",
      "r283",
      "r284",
      "r288"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount after tax of other comprehensive income (loss) attributable to parent entity.",
        "label": "Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent",
        "terseLabel": "Other comprehensive losses"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossTaxAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Other Comprehensive Income (Loss), Tax [Abstract]",
        "terseLabel": "Other comprehensive loss:"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossTaxAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax": {
     "auth_ref": [
      "r55",
      "r57"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 12.0,
       "parentTag": "us-gaap_ComprehensiveIncomeNetOfTax",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, after tax and before adjustment, of unrealized holding gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Excludes unrealized gain (loss) on investment in debt security measured at amortized cost (held-to-maturity) from transfer to available-for-sale.",
        "label": "Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax",
        "terseLabel": "Net unrealized gain (loss) on marketable securities, net of tax"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherLiabilitiesNoncurrent": {
     "auth_ref": [
      "r43"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 13.0,
       "parentTag": "us-gaap_Liabilities",
       "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 liabilities, noncurrent"
       }
      }
     },
     "localname": "OtherLiabilitiesNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherNonoperatingIncomeExpense": {
     "auth_ref": [
      "r74"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 8.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "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)",
        "totalLabel": "Total other income, net"
       }
      }
     },
     "localname": "OtherNonoperatingIncomeExpense",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsForTenantImprovements": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow for the allowance granted to lessee and/or direct costs incurred by lessor used to prepare the leased premises for tenant's occupancy.",
        "label": "Payments for Tenant Improvements",
        "terseLabel": "Repayment of tenant inducement allowance"
       }
      }
     },
     "localname": "PaymentsForTenantImprovements",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsOfDebtIssuanceCosts": {
     "auth_ref": [
      "r77"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 10.0,
       "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",
        "negatedLabel": "Payments of debt issuance costs",
        "terseLabel": "Debt issuance costs paid"
       }
      }
     },
     "localname": "PaymentsOfDebtIssuanceCosts",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows",
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation": {
     "auth_ref": [
      "r76"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 9.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow to satisfy grantee's tax withholding obligation for award under share-based payment arrangement.",
        "label": "Payments Related to Tax Withholding for Share-based Compensation",
        "negatedLabel": "Tax paid related to net share settlement of equity awards"
       }
      }
     },
     "localname": "PaymentsRelatedToTaxWithholdingForShareBasedCompensation",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquireMarketableSecurities": {
     "auth_ref": [
      "r154"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 5.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash outflow for purchase of marketable security.",
        "label": "Payments to Acquire Marketable Securities",
        "negatedLabel": "Purchase of marketable securities"
       }
      }
     },
     "localname": "PaymentsToAcquireMarketableSecurities",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquirePropertyPlantAndEquipment": {
     "auth_ref": [
      "r75"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "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": "Purchase of property and equipment"
       }
      }
     },
     "localname": "PaymentsToAcquirePropertyPlantAndEquipment",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PlanNameAxis": {
     "auth_ref": [
      "r233",
      "r262"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationStockBasedCompensationExpenseRecognizedDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationStockBasedCompensationExpenseRecognizedDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PreferredStockParOrStatedValuePerShare": {
     "auth_ref": [
      "r16"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.",
        "label": "Preferred Stock, Par or Stated Value Per Share",
        "terseLabel": "Preferred stock, par value"
       }
      }
     },
     "localname": "PreferredStockParOrStatedValuePerShare",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_PreferredStockSharesAuthorized": {
     "auth_ref": [
      "r16"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_PreferredStockSharesIssued": {
     "auth_ref": [
      "r16"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt.",
        "label": "Preferred Stock, Shares Issued",
        "terseLabel": "Preferred stock, shares issued"
       }
      }
     },
     "localname": "PreferredStockSharesIssued",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_PreferredStockSharesOutstanding": {
     "auth_ref": [
      "r16"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.",
        "label": "Preferred Stock, Shares Outstanding",
        "terseLabel": "Preferred stock, shares outstanding"
       }
      }
     },
     "localname": "PreferredStockSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_PreferredStockValue": {
     "auth_ref": [
      "r16"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 21.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate par or stated value of issued nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable preferred shares, par value and other disclosure concepts are in another section within stockholders' equity.",
        "label": "Preferred Stock, Value, Issued",
        "verboseLabel": "Preferred stock, $0.001 par value, 5,000,000 shares authorized as of June 30, 2021 (unaudited) and December 31, 2020; no shares issued and outstanding"
       }
      }
     },
     "localname": "PreferredStockValue",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PrepaidExpenseAndOtherAssetsCurrent": {
     "auth_ref": [
      "r4",
      "r29",
      "r30"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 10.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "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 in future periods, and amount of other assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer.",
        "label": "Prepaid Expense and Other Assets, Current",
        "verboseLabel": "Prepaid expenses and other current assets"
       }
      }
     },
     "localname": "PrepaidExpenseAndOtherAssetsCurrent",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities": {
     "auth_ref": [],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cash inflow associated with the aggregate amount received by the entity through sale or maturity of marketable securities  (held-to-maturity or available-for-sale) during the period.",
        "label": "Proceeds from Sale and Maturity of Marketable Securities",
        "terseLabel": "Maturities of marketable securities"
       }
      }
     },
     "localname": "ProceedsFromSaleAndMaturityOfMarketableSecurities",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentAdditions": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of acquisition of long-lived, 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, furniture and fixtures, and computer equipment.",
        "label": "Property, Plant and Equipment, Additions",
        "verboseLabel": "Property palnt and equipment additions"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentAdditions",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentByTypeAxis": {
     "auth_ref": [
      "r33",
      "r191"
     ],
     "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, Type [Axis]"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentByTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail",
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail",
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentGross": {
     "auth_ref": [
      "r32",
      "r189"
     ],
     "calculation": {
      "http://www.gbt.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail": {
       "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": "Total property and equipment"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentGross",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentNet": {
     "auth_ref": [
      "r12",
      "r13",
      "r191",
      "r395"
     ],
     "calculation": {
      "http://www.gbt.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 3.0,
       "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 and equipment, net",
        "totalLabel": "Property and equipment, net"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentNet",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail",
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentTextBlock": {
     "auth_ref": [
      "r12",
      "r191"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of 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 Text Block]",
        "terseLabel": "Property and Equipment, Net"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentTypeDomain": {
     "auth_ref": [
      "r12",
      "r189"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail",
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail",
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ReceivablesNetCurrent": {
     "auth_ref": [
      "r18",
      "r25",
      "r394",
      "r417"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 8.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The total amount due to the entity within one year of the balance sheet date (or one operating cycle, if longer) from outside sources, including trade accounts receivable, notes and loans receivable, as well as any other types of receivables, net of allowances established for the purpose of reducing such receivables to an amount that approximates their net realizable value.",
        "label": "Receivables, Net, Current",
        "terseLabel": "Accounts receivable, net"
       }
      }
     },
     "localname": "ReceivablesNetCurrent",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ResearchAndDevelopmentExpense": {
     "auth_ref": [
      "r276",
      "r420"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 5.0,
       "parentTag": "us-gaap_CostsAndExpenses",
       "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ResearchAndDevelopmentExpenseMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Primary financial statement caption in which the reported facts about research and development expense have been included.",
        "label": "Research and Development Expense [Member]",
        "verboseLabel": "Research and Development Expense [Member]"
       }
      }
     },
     "localname": "ResearchAndDevelopmentExpenseMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationStockBasedCompensationExpenseRecognizedDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue": {
     "auth_ref": [
      "r2",
      "r11",
      "r85",
      "r90"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as current. 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": "Restricted Cash and Cash Equivalents, Current",
        "totalLabel": "Total cash and cash equivalents and restricted cash"
       }
      }
     },
     "localname": "RestrictedCashAndCashEquivalentsAtCarryingValue",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Type of cash and cash equivalent. Cash is 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 [Domain]",
        "terseLabel": "Cash and Cash Equivalents [Domain]"
       }
      }
     },
     "localname": "RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RestrictedCashAndCashEquivalentsNoncurrent": {
     "auth_ref": [
      "r6",
      "r14",
      "r85",
      "r90",
      "r419"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as noncurrent. 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": "Restricted Cash and Cash Equivalents, Noncurrent",
        "terseLabel": "Restricted cash"
       }
      }
     },
     "localname": "RestrictedCashAndCashEquivalentsNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RestrictedCashCurrent": {
     "auth_ref": [
      "r2",
      "r11",
      "r90"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "parentTag": "us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount of cash restricted as to withdrawal or usage, classified as current. 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, Current",
        "terseLabel": "Restricted cash"
       }
      }
     },
     "localname": "RestrictedCashCurrent",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "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": "RSU [Member]"
       }
      }
     },
     "localname": "RestrictedStockUnitsRSUMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/NetLossPerSharePotentiallyDilutiveSecuritiesThatWereNotIncludedInDilutedNetLossPerShareCalculationsDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RetainedEarningsAccumulatedDeficit": {
     "auth_ref": [
      "r20",
      "r215",
      "r270",
      "r392",
      "r408",
      "r413"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 25.0,
       "parentTag": "us-gaap_StockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cumulative amount of the reporting entity's undistributed earnings or deficit.",
        "label": "Retained Earnings (Accumulated Deficit)",
        "terseLabel": "Accumulated deficit",
        "verboseLabel": "Cumulative net losses"
       }
      }
     },
     "localname": "RetainedEarningsAccumulatedDeficit",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets",
      "http://www.gbt.com/role/OrganizationAndBasisOfPresentationAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RetainedEarningsMember": {
     "auth_ref": [
      "r96",
      "r97",
      "r99",
      "r101",
      "r109",
      "r112",
      "r170",
      "r267",
      "r268",
      "r269",
      "r279",
      "r280",
      "r404",
      "r406"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The cumulative amount of the reporting entity's undistributed earnings or deficit.",
        "label": "Retained Earnings [Member]",
        "terseLabel": "Accumulated Deficit [Member]"
       }
      }
     },
     "localname": "RetainedEarningsMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax": {
     "auth_ref": [
      "r134",
      "r135",
      "r138",
      "r143",
      "r144",
      "r148",
      "r149",
      "r150",
      "r216",
      "r217",
      "r366"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 3.0,
       "parentTag": "us-gaap_OperatingIncomeLoss",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.",
        "label": "Revenue from Contract with Customer, Including Assessed Tax",
        "terseLabel": "Product sales, net"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerIncludingAssessedTax",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RevenuesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Revenues [Abstract]"
       }
      }
     },
     "localname": "RevenuesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability": {
     "auth_ref": [
      "r328",
      "r332"
     ],
     "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": "ROU assets obtained in exchange for new operating lease"
       }
      }
     },
     "localname": "RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesSupplementalCashFlowInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_SaleOfStockNameOfTransactionDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Sale of the entity's stock, including, but not limited to, initial public offering (IPO) and private placement.",
        "label": "Sale of Stock [Domain]",
        "terseLabel": "Sale of Stock [Domain]"
       }
      }
     },
     "localname": "SaleOfStockNameOfTransactionDomain",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/OrganizationAndBasisOfPresentationAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SalesRevenueProductLineMember": {
     "auth_ref": [
      "r128"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Revenue from specified product or service, when it serves as benchmark in concentration of risk calculation. Includes, but is not limited to, revenue from contract with customer and other sources.",
        "label": "Revenue, Product and Service Benchmark [Member]",
        "terseLabel": "Revenue, Product and Service Benchmark [Member]"
       }
      }
     },
     "localname": "SalesRevenueProductLineMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "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]",
        "terseLabel": "Accrued Liabilities"
       }
      }
     },
     "localname": "ScheduleOfAccruedLiabilitiesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable": {
     "auth_ref": [
      "r115"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule for securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) in the future that were not included in the computation of diluted EPS because to do so would increase EPS amounts or decrease loss per share amounts for the period presented, by Antidilutive Securities.",
        "label": "Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table]",
        "terseLabel": "Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table]"
       }
      }
     },
     "localname": "ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/NetLossPerSharePotentiallyDilutiveSecuritiesThatWereNotIncludedInDilutedNetLossPerShareCalculationsDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock": {
     "auth_ref": [
      "r115"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) in the future that were not included in the computation of diluted EPS because to do so would increase EPS amounts or decrease loss per share amounts for the period presented, by antidilutive securities.",
        "label": "Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]",
        "terseLabel": "Potentially Dilutive Securities that were Not Included in Diluted Net Loss per Share Calculations"
       }
      }
     },
     "localname": "ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/NetLossPerShareTables"
     ],
     "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]"
       }
      }
     },
     "localname": "ScheduleOfAvailableForSaleSecuritiesLineItems",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfAvailableForSaleSecuritiesTable": {
     "auth_ref": [
      "r157",
      "r158",
      "r161",
      "r162",
      "r163",
      "r164",
      "r384",
      "r385"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities.",
        "label": "Schedule of Available-for-sale Securities [Table]",
        "terseLabel": "Schedule of Available-for-sale Securities [Table]"
       }
      }
     },
     "localname": "ScheduleOfAvailableForSaleSecuritiesTable",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable": {
     "auth_ref": [
      "r232",
      "r258",
      "r272"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Disclosure of information about amount recognized for award under share-based payment arrangement. Includes, but is not limited to, amount expensed in statement of income or comprehensive income, amount capitalized in statement of financial position, and corresponding reporting line item in financial statements.",
        "label": "Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table]",
        "terseLabel": "Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table]"
       }
      }
     },
     "localname": "ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationStockBasedCompensationExpenseRecognizedDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock": {
     "auth_ref": [
      "r232",
      "r258",
      "r272"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of allocation of amount expensed and capitalized for award under share-based payment arrangement to statement of income or comprehensive income and statement of financial position. Includes, but is not limited to, corresponding line item in financial statement.",
        "label": "Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]",
        "terseLabel": "Stock-based Compensation Expense Recognized"
       }
      }
     },
     "localname": "ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfInventoryCurrentTableTextBlock": {
     "auth_ref": [
      "r10",
      "r26",
      "r27",
      "r28"
     ],
     "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": "Inventories"
       }
      }
     },
     "localname": "ScheduleOfInventoryCurrentTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock": {
     "auth_ref": [
      "r198"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of maturity and sinking fund requirement for long-term debt.",
        "label": "Schedule of Maturities of Long-term Debt [Table Text Block]",
        "terseLabel": "Schedule of Future payments of principal and interest on the Term Loan"
       }
      }
     },
     "localname": "ScheduleOfMaturitiesOfLongTermDebtTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfPropertyPlantAndEquipmentTable": {
     "auth_ref": [
      "r33",
      "r191"
     ],
     "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": "Property, Plant and Equipment [Table]"
       }
      }
     },
     "localname": "ScheduleOfPropertyPlantAndEquipmentTable",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponentsPropertyAndEquipmentDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock": {
     "auth_ref": [
      "r243",
      "r248",
      "r249"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Tabular disclosure of activity for award under share-based payment arrangement. Includes, but is not limited to, outstanding award at beginning and end of year, granted, exercised, forfeited, and weighted-average grant date fair value.",
        "label": "Share-based Compensation, Activity [Table Text Block]",
        "terseLabel": "Summary of Activity of Market-Condition Awards"
       }
      }
     },
     "localname": "ScheduleOfShareBasedCompensationActivityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable": {
     "auth_ref": [
      "r233",
      "r262"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfShareBasedCompensationArrangementsByShareBasedPaymentAwardDetail",
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail",
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsOfMarketConditionAwardsDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock": {
     "auth_ref": [
      "r237",
      "r248",
      "r249"
     ],
     "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 Compensation, Stock Options, Activity [Table Text Block]",
        "terseLabel": "Stock Option Activity"
       }
      }
     },
     "localname": "ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock": {
     "auth_ref": [
      "r252"
     ],
     "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": "Valuation Assumptions for Stock Awards"
       }
      }
     },
     "localname": "ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfStockByClassTable": {
     "auth_ref": [
      "r45",
      "r92",
      "r121",
      "r122",
      "r205",
      "r206",
      "r207",
      "r209",
      "r210",
      "r211",
      "r212",
      "r213",
      "r214",
      "r215"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Schedule detailing information related to equity by class of stock. Class of stock includes common, convertible, and preferred stocks which are not redeemable or redeemable solely at the option of the issuer. It also includes preferred stock with redemption features that are solely within the control of the issuer and mandatorily redeemable stock if redemption is required to occur only upon liquidation or termination of the reporting entity.",
        "label": "Schedule of Stock by Class [Table]",
        "terseLabel": "Schedule of Stock by Class [Table]"
       }
      }
     },
     "localname": "ScheduleOfStockByClassTable",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/OrganizationAndBasisOfPresentationAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SecuredDebtMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Collateralized debt obligation backed by, for example, but not limited to, pledge, mortgage or other lien on the entity's assets.",
        "label": "Secured Debt [Member]",
        "terseLabel": "Secured Debt"
       }
      }
     },
     "localname": "SecuredDebtMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SecurityOwnedAndSoldNotYetPurchasedAtFairValueAxis": {
     "auth_ref": [
      "r372"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Group of financial instruments held by a broker-dealer for their own account (proprietary securities) for trading or investment purposes that are carried at fair value including securities sold, not yet purchased.",
        "label": "Security Owned and Sold, Not yet Purchased, at Fair Value [Axis]",
        "terseLabel": "Security Owned and Sold, Not yet Purchased, at Fair Value [Axis]"
       }
      }
     },
     "localname": "SecurityOwnedAndSoldNotYetPurchasedAtFairValueAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail",
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityNameDomain": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Type of financial instrument held by a broker-dealer for their own account (proprietary securities) for trading or investment purposes that are carried at fair value including securities sold, not yet purchased.",
        "label": "Security Owned and Sold, Not yet Purchased Fair Value, Security Name [Domain]",
        "terseLabel": "Security Owned and Sold, Not yet Purchased Fair Value, Security Name [Domain]"
       }
      }
     },
     "localname": "SecurityOwnedAndSoldNotYetPurchasedFairValueSecurityNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail",
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SellingGeneralAndAdministrativeExpense": {
     "auth_ref": [
      "r72"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 7.0,
       "parentTag": "us-gaap_CostsAndExpenses",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.",
        "label": "Selling, General and Administrative Expense",
        "terseLabel": "Selling, general and administrative"
       }
      }
     },
     "localname": "SellingGeneralAndAdministrativeExpense",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_SellingGeneralAndAdministrativeExpensesMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Primary financial statement caption encompassing selling, general and administrative expense.",
        "label": "Selling, General and Administrative Expenses [Member]",
        "terseLabel": "Selling, general and administrative [Member]"
       }
      }
     },
     "localname": "SellingGeneralAndAdministrativeExpensesMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationStockBasedCompensationExpenseRecognizedDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ShareBasedCompensation": {
     "auth_ref": [
      "r82"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows": {
       "order": 23.0,
       "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 Compensation",
        "terseLabel": "Stock-based compensation"
       }
      }
     },
     "localname": "ShareBasedCompensation",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows",
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod": {
     "auth_ref": [
      "r241"
     ],
     "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": "Number of Units forfeited",
        "negatedTerseLabel": "RSUs forfeited, Number of RSUs"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r247"
     ],
     "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": "RSUs forfeited, Weighted-Average Grant Date Fair Value",
        "verboseLabel": "Weighted-Average Grant Date Fair Value forfeited"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod": {
     "auth_ref": [
      "r245"
     ],
     "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",
        "positiveLabel": "RSUs granted, Number of RSUs",
        "terseLabel": "Number of Units granted"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r245"
     ],
     "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": "RSUs granted, Weighted-Average Grant Date Fair Value",
        "verboseLabel": "Weighted-Average Grant Date Fair Value granted"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber": {
     "auth_ref": [
      "r244"
     ],
     "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": "Ending Balance - Non-vested market-condition awards",
        "periodStartLabel": "Beginning Balance - Non-vested market-condition awards",
        "verboseLabel": "Number of shares Non-vested period"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r244"
     ],
     "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": "Ending Balance - Non-vested units, Weighted-Average Grant Date Fair Value",
        "periodStartLabel": "Beginning Balance - Non-vested units, Weighted-Average Grant Date Fair Value"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms": {
     "auth_ref": [
      "r250"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms",
        "terseLabel": "Non-vested units, Weighted-Average remaining vesting period(years)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod": {
     "auth_ref": [
      "r246"
     ],
     "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",
        "negatedTerseLabel": "RSUs vested, Number of RSUs"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r246"
     ],
     "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": "RSUs vested, Weighted-Average Grant Date Fair Value"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate": {
     "auth_ref": [
      "r255"
     ],
     "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": "Dividend yield"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMaximum": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The estimated measure of the maximum 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, Maximum",
        "terseLabel": "Volatility, maximum"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMaximum",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMinimum": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The estimated measure of the minimum 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, Minimum",
        "terseLabel": "Volatility, minimum"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMinimum",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate": {
     "auth_ref": [
      "r256"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The maximum 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, Maximum",
        "terseLabel": "Risk-free interest rate, maximum"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The minimum 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, Minimum",
        "terseLabel": "Risk-free interest rate, minimum"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfShareBasedCompensationArrangementsByShareBasedPaymentAwardDetail",
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail",
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsOfMarketConditionAwardsDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized": {
     "auth_ref": [
      "r234"
     ],
     "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": "Shares authorized for issuance"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod": {
     "auth_ref": [
      "r242"
     ],
     "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": "Options canceled, Number of Options"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationStockOptionActivityDetail"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice": {
     "auth_ref": [
      "r242"
     ],
     "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": "Options canceled, Weighted-Average Exercise Price"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationStockOptionActivityDetail"
     ],
     "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",
        "verboseLabel": "Options granted, Number of Options"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationStockOptionActivityDetail"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber": {
     "auth_ref": [
      "r239",
      "r262"
     ],
     "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": "Ending balance, outstanding, Number of Options",
        "periodStartLabel": "Beginning balance, outstanding, Number of Options"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationStockOptionActivityDetail"
     ],
     "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]"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice": {
     "auth_ref": [
      "r238"
     ],
     "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": "Ending balance, Outstanding, Weighted-Average Exercise Price",
        "periodStartLabel": "Beginning balance, Outstanding, Weighted-Average Exercise Price"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationStockOptionActivityDetail"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]",
        "terseLabel": "Weighted- Average Exercise Price"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationStockOptionActivityDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber": {
     "auth_ref": [
      "r251"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of fully vested and expected to vest exercisable options that may 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, Exercisable, Number",
        "terseLabel": "Number of Units Allowed"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfShareBasedCompensationArrangementsByShareBasedPaymentAwardDetail"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice": {
     "auth_ref": [
      "r250"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price",
        "verboseLabel": "Stock Price Targets"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfShareBasedCompensationArrangementsByShareBasedPaymentAwardDetail"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain": {
     "auth_ref": [
      "r231",
      "r235"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Award under share-based payment arrangement.",
        "label": "Equity Award [Domain]",
        "terseLabel": "Equity Award [Domain]"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfRsuActivityGrantedToEmployeesWithServiceBasedVestingDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfShareBasedCompensationArrangementsByShareBasedPaymentAwardDetail",
      "http://www.gbt.com/role/StockBasedCompensationTables",
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail",
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsOfMarketConditionAwardsDetail"
     ],
     "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": "Options exercised, Weighted-Average Exercise Price"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationStockOptionActivityDetail"
     ],
     "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",
        "verboseLabel": "Options granted, Weighted-Average Exercise Price"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationStockOptionActivityDetail"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationAwardTrancheOneMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "First portion of award under share-based payment arrangement differentiated by vesting feature, including, but not limited to, performance measure or service period.",
        "label": "Share-based Payment Arrangement, Tranche One [Member]",
        "terseLabel": "Tranche One [Member]"
       }
      }
     },
     "localname": "ShareBasedCompensationAwardTrancheOneMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfShareBasedCompensationArrangementsByShareBasedPaymentAwardDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ShareBasedCompensationAwardTrancheThreeMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Third portion of award under share-based payment arrangement differentiated by vesting feature, including, but not limited to, performance measure or service period.",
        "label": "Share-based Payment Arrangement, Tranche Three [Member]",
        "terseLabel": "Tranche Three [Member]"
       }
      }
     },
     "localname": "ShareBasedCompensationAwardTrancheThreeMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfShareBasedCompensationArrangementsByShareBasedPaymentAwardDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ShareBasedCompensationAwardTrancheTwoMember": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Second portion of award under share-based payment arrangement differentiated by vesting feature, including, but not limited to, performance measure or service period.",
        "label": "Share-based Payment Arrangement, Tranche Two [Member]",
        "terseLabel": "Tranche Two [Member]"
       }
      }
     },
     "localname": "ShareBasedCompensationAwardTrancheTwoMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfShareBasedCompensationArrangementsByShareBasedPaymentAwardDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionValuationMethodExpectedDividendRate": {
     "auth_ref": [
      "r255"
     ],
     "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 expected term of a nonvested share or option award issued to other than an employee.",
        "label": "Share-based Goods and Nonemployee Services Transaction, Valuation Method, Expected Dividend Rate",
        "terseLabel": "Dividend yield"
       }
      }
     },
     "localname": "ShareBasedGoodsAndNonemployeeServicesTransactionValuationMethodExpectedDividendRate",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsOfMarketConditionAwardsDetail"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionValuationMethodExpectedTerm1": {
     "auth_ref": [
      "r253"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Period an equity-based award is expected to be outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.",
        "label": "Share-based Goods and Nonemployee Services Transaction, Valuation Method, Expected Term",
        "terseLabel": "Expected term"
       }
      }
     },
     "localname": "ShareBasedGoodsAndNonemployeeServicesTransactionValuationMethodExpectedTerm1",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsOfMarketConditionAwardsDetail"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionValuationMethodExpectedVolatilityRate": {
     "auth_ref": [
      "r254"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The estimated measure of the percentage amount by which a share price is expected to fluctuate during the expected term of a nonvested share or option award issued to other than an employee.",
        "label": "Share-based Goods and Nonemployee Services Transaction, Valuation Method, Expected Volatility Rate",
        "terseLabel": "Volatility"
       }
      }
     },
     "localname": "ShareBasedGoodsAndNonemployeeServicesTransactionValuationMethodExpectedVolatilityRate",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsOfMarketConditionAwardsDetail"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_ShareBasedGoodsAndNonemployeeServicesTransactionValuationMethodRiskFreeInterestRate": {
     "auth_ref": [
      "r256"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "The risk-free interest rate assumption that is used in valuing a nonvested share or option award issued to other than an employee.",
        "label": "Share-based Goods and Nonemployee Services Transaction, Valuation Method, Risk Free Interest Rate",
        "terseLabel": "Risk-free interest rate"
       }
      }
     },
     "localname": "ShareBasedGoodsAndNonemployeeServicesTransactionValuationMethodRiskFreeInterestRate",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsOfMarketConditionAwardsDetail"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_SharePrice": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Price of a single share of a number of saleable stocks of a company.",
        "label": "Share Price",
        "verboseLabel": "Valuation date stock price"
       }
      }
     },
     "localname": "SharePrice",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsOfMarketConditionAwardsDetail"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Intrinsic 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, Aggregate Intrinsic Value, Nonvested",
        "terseLabel": "Non-vested units, Aggregate Intrinsic Value"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfActivityOfMarketConditionAwardsDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1": {
     "auth_ref": [
      "r253",
      "r271"
     ],
     "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",
        "verboseLabel": "Expected term (in years)"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationValuationAssumptionsForStockOptionsGrantedDetail"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_SharesOutstanding": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Number of shares issued which are neither cancelled nor held in the treasury.",
        "label": "Shares, Outstanding",
        "periodEndLabel": "Ending Balance, Shares",
        "periodStartLabel": "Beginning Balance, Shares"
       }
      }
     },
     "localname": "SharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_SignificantAccountingPoliciesTextBlock": {
     "auth_ref": [
      "r95"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_StatementEquityComponentsAxis": {
     "auth_ref": [
      "r46",
      "r96",
      "r97",
      "r99",
      "r101",
      "r109",
      "r112",
      "r120",
      "r170",
      "r208",
      "r215",
      "r267",
      "r268",
      "r269",
      "r279",
      "r280",
      "r307",
      "r308",
      "r309",
      "r310",
      "r311",
      "r312",
      "r404",
      "r405",
      "r406"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by component of equity.",
        "label": "Equity Components [Axis]",
        "terseLabel": "Equity Components [Axis]"
       }
      }
     },
     "localname": "StatementEquityComponentsAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity",
      "http://www.gbt.com/role/OrganizationAndBasisOfPresentationAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity",
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfCashFlowsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Statement of Cash Flows [Abstract]"
       }
      }
     },
     "localname": "StatementOfCashFlowsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfFinancialPositionAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Statement of Financial Position [Abstract]"
       }
      }
     },
     "localname": "StatementOfFinancialPositionAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementOfStockholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Statement of Stockholders' Equity [Abstract]"
       }
      }
     },
     "localname": "StatementOfStockholdersEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementTable": {
     "auth_ref": [
      "r96",
      "r97",
      "r99",
      "r120",
      "r366"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity",
      "http://www.gbt.com/role/LongTermDebtAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationTables"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans": {
     "auth_ref": [
      "r16",
      "r17",
      "r208",
      "r215"
     ],
     "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 common stock pursuant to ESPP purchases, Shares"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross": {
     "auth_ref": [
      "r208",
      "r215"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total number of shares issued during the period, including shares forfeited, as a result of Restricted Stock Awards.",
        "label": "Stock Issued During Period, Shares, Restricted Stock Award, Gross",
        "terseLabel": "Issuance of common stock upon vesting of restricted share units, net of shares withheld for employee taxes, Shares"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodSharesRestrictedStockAwardGross",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised": {
     "auth_ref": [
      "r16",
      "r17",
      "r208",
      "r215",
      "r240"
     ],
     "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": "Options exercised, Number of Options",
        "terseLabel": "Issuance of common stock upon exercise of stock options, Shares"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodSharesStockOptionsExercised",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity",
      "http://www.gbt.com/role/StockBasedCompensationStockOptionActivityDetail"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan": {
     "auth_ref": [
      "r16",
      "r17",
      "r208",
      "r215"
     ],
     "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 common stock pursuant to ESPP purchases"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodValueEmployeeStockPurchasePlan",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross": {
     "auth_ref": [
      "r16",
      "r17",
      "r208",
      "r215"
     ],
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Aggregate value of stock related to Restricted Stock Awards issued during the period.",
        "label": "Stock Issued During Period, Value, Restricted Stock Award, Gross",
        "terseLabel": "Issuance of common stock upon vesting of restricted share units, net of shares withheld for employee taxes"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodValueRestrictedStockAwardGross",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised": {
     "auth_ref": [
      "r46",
      "r208",
      "r215"
     ],
     "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": "Issuance of common stock upon exercise of stock options"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodValueStockOptionsExercised",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockholdersEquity": {
     "auth_ref": [
      "r17",
      "r22",
      "r23",
      "r93",
      "r152",
      "r166",
      "r305"
     ],
     "calculation": {
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets": {
       "order": 20.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.",
        "label": "Stockholders' Equity Attributable to Parent",
        "periodEndLabel": "Ending Balance",
        "periodStartLabel": "Beginning Balance",
        "totalLabel": "Total stockholders' equity"
       }
      }
     },
     "localname": "StockholdersEquity",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets",
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockholdersEquityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Stockholders' Equity Attributable to Parent [Abstract]",
        "terseLabel": "Stockholders' equity:"
       }
      }
     },
     "localname": "StockholdersEquityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SubsequentEventTypeAxis": {
     "auth_ref": [
      "r313",
      "r334"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail",
      "http://www.gbt.com/role/OrganizationAndBasisOfPresentationAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SubsequentEventTypeDomain": {
     "auth_ref": [
      "r313",
      "r334"
     ],
     "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/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail",
      "http://www.gbt.com/role/OrganizationAndBasisOfPresentationAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_SubsidiarySaleOfStockAxis": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by type of sale of the entity's stock.",
        "label": "Sale of Stock [Axis]",
        "terseLabel": "Sale of Stock [Axis]"
       }
      }
     },
     "localname": "SubsidiarySaleOfStockAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/OrganizationAndBasisOfPresentationAdditionalInformationDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SupplementalBalanceSheetDisclosuresTextBlock": {
     "auth_ref": [
      "r53"
     ],
     "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]",
        "terseLabel": "Balance Sheet Components"
       }
      }
     },
     "localname": "SupplementalBalanceSheetDisclosuresTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/BalanceSheetComponents"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SupplementalCashFlowInformationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Supplemental Cash Flow Information [Abstract]",
        "verboseLabel": "SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:"
       }
      }
     },
     "localname": "SupplementalCashFlowInformationAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_TextBlockAbstract": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "label": "Text Block [Abstract]"
       }
      }
     },
     "localname": "TextBlockAbstract",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain": {
     "auth_ref": [
      "r159",
      "r160",
      "r335",
      "r336",
      "r337",
      "r338",
      "r339",
      "r340",
      "r341",
      "r342",
      "r343",
      "r344",
      "r345",
      "r346",
      "r347",
      "r348",
      "r349",
      "r350",
      "r351",
      "r352",
      "r353",
      "r354",
      "r355",
      "r356",
      "r357",
      "r358",
      "r359",
      "r360",
      "r361",
      "r362",
      "r363",
      "r364"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Instrument or contract that imposes a contractual obligation to deliver cash or another financial instrument or to exchange other financial instruments on potentially unfavorable terms and conveys a contractual right to receive cash or another financial instrument or to exchange other financial instruments on potentially favorable terms.",
        "label": "Financial Instruments [Domain]"
       }
      }
     },
     "localname": "TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_TypeOfAdoptionMember": {
     "auth_ref": [
      "r100",
      "r101",
      "r102",
      "r103",
      "r167",
      "r168",
      "r169",
      "r170",
      "r171",
      "r172",
      "r263",
      "r264",
      "r265",
      "r266",
      "r267",
      "r268",
      "r269",
      "r270",
      "r277",
      "r278",
      "r279",
      "r280",
      "r368",
      "r369",
      "r370",
      "r402",
      "r403",
      "r404",
      "r405",
      "r406",
      "r407",
      "r408",
      "r409",
      "r410",
      "r411",
      "r412",
      "r413"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Amendment to accounting standards.",
        "label": "Type of Adoption [Domain]",
        "terseLabel": "Type of Adoption [Domain]"
       }
      }
     },
     "localname": "TypeOfAdoptionMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesSupplementalCashFlowInformationDetail",
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_USGovernmentAgenciesDebtSecuritiesMember": {
     "auth_ref": [
      "r220",
      "r383"
     ],
     "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": "U.S. Government Agency Securities [Member]"
       }
      }
     },
     "localname": "USGovernmentAgenciesDebtSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail",
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_USGovernmentDebtSecuritiesMember": {
     "auth_ref": [
      "r383"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Debt securities issued by the United States government.",
        "label": "US Government Debt Securities [Member]",
        "terseLabel": "U.S. Government Securities [Member]"
       }
      }
     },
     "localname": "USGovernmentDebtSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/AvailableForSaleSecuritiesSummaryOfAvailableForSaleSecuritiesDetail",
      "http://www.gbt.com/role/FairValueMeasurementsFairValueAssetsMeasuredOnRecurringBasisDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_UseOfEstimates": {
     "auth_ref": [
      "r123",
      "r124",
      "r125",
      "r126",
      "r131",
      "r132",
      "r133"
     ],
     "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]",
        "terseLabel": "Use of Estimates"
       }
      }
     },
     "localname": "UseOfEstimates",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/SummaryOfSignificantAccountingPoliciesPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_VariableLeaseCost": {
     "auth_ref": [
      "r326",
      "r332"
     ],
     "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",
        "verboseLabel": "variable lease cost"
       }
      }
     },
     "localname": "VariableLeaseCost",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CommitmentsAndContingenciesAdditionalInformationDetail"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_VestingAxis": {
     "auth_ref": [
      "r262"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Information by vesting schedule of award under share-based payment arrangement.",
        "label": "Vesting [Axis]"
       }
      }
     },
     "localname": "VestingAxis",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfShareBasedCompensationArrangementsByShareBasedPaymentAwardDetail"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_VestingDomain": {
     "auth_ref": [
      "r262"
     ],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Vesting schedule of award under share-based payment arrangement.",
        "label": "Vesting [Domain]"
       }
      }
     },
     "localname": "VestingDomain",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/StockBasedCompensationPlanSummaryAdditionalInformationDetail",
      "http://www.gbt.com/role/StockBasedCompensationSummaryOfShareBasedCompensationArrangementsByShareBasedPaymentAwardDetail"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted": {
     "auth_ref": [],
     "lang": {
      "en-us": {
       "role": {
        "documentation": "Average number of shares or units issued and outstanding that are used in calculating basic and diluted earnings per share (EPS).",
        "label": "Weighted Average Number of Shares Outstanding, Basic and Diluted",
        "terseLabel": "Weighted-average number of shares used in computing basic and diluted net loss per common share"
       }
      }
     },
     "localname": "WeightedAverageNumberOfShareOutstandingBasicAndDiluted",
     "nsuri": "http://fasb.org/us-gaap/2020-01-31",
     "presentation": [
      "http://www.gbt.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "sharesItemType"
    }
   },
   "unitCount": 7
  }
 },
 "std_ref": {
  "r0": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "205",
   "URI": "http://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760"
  },
  "r1": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "205",
   "URI": "http://asc.fasb.org/topic&trid=2122149"
  },
  "r10": {
   "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"
  },
  "r100": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(2)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794"
  },
  "r101": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(3)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794"
  },
  "r102": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(4)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794"
  },
  "r103": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794"
  },
  "r104": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794"
  },
  "r105": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22694-107794"
  },
  "r106": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22583-107794"
  },
  "r107": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22595-107794"
  },
  "r108": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22644-107794"
  },
  "r109": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22644-107794"
  },
  "r11": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(1))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r110": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22644-107794"
  },
  "r111": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22658-107794"
  },
  "r112": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22663-107794"
  },
  "r113": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "60B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=121326447&loc=SL5780133-109256"
  },
  "r114": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=121326447&loc=d3e1337-109256"
  },
  "r115": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257"
  },
  "r116": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=6371337&loc=d3e3630-109257"
  },
  "r117": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=109243012&loc=SL65017193-207537"
  },
  "r118": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=120380238&loc=d3e3842-109258"
  },
  "r119": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "260",
   "URI": "http://asc.fasb.org/topic&trid=2144383"
  },
  "r12": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(13))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r120": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "272",
   "URI": "http://asc.fasb.org/extlink&oid=6828210&loc=d3e70191-108054"
  },
  "r121": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "272",
   "URI": "http://asc.fasb.org/extlink&oid=6828210&loc=d3e70229-108054"
  },
  "r122": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "272",
   "URI": "http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055"
  },
  "r123": {
   "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"
  },
  "r124": {
   "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"
  },
  "r125": {
   "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"
  },
  "r126": {
   "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"
  },
  "r127": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "18",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "275",
   "URI": "http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592"
  },
  "r128": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "18",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "275",
   "URI": "http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592"
  },
  "r129": {
   "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"
  },
  "r13": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(14))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r130": {
   "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"
  },
  "r131": {
   "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"
  },
  "r132": {
   "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"
  },
  "r133": {
   "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"
  },
  "r134": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599"
  },
  "r135": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599"
  },
  "r136": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599"
  },
  "r137": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599"
  },
  "r138": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "30",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599"
  },
  "r139": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "30",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599"
  },
  "r14": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(17))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r140": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "30",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599"
  },
  "r141": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "30",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e8906-108599"
  },
  "r142": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "31",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e8924-108599"
  },
  "r143": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599"
  },
  "r144": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599"
  },
  "r145": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599"
  },
  "r146": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599"
  },
  "r147": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e8933-108599"
  },
  "r148": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "40",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e9031-108599"
  },
  "r149": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "41",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e9038-108599"
  },
  "r15": {
   "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=120391452&loc=d3e13212-122682"
  },
  "r150": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "42",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=120311839&loc=d3e9054-108599"
  },
  "r151": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=121593590&loc=d3e4647-111522"
  },
  "r152": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 4.E)",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707"
  },
  "r153": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=121553693&loc=d3e26610-111562"
  },
  "r154": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=121553693&loc=d3e26853-111562"
  },
  "r155": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(aa)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=121645371&loc=d3e27161-111563"
  },
  "r156": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=121645371&loc=d3e27161-111563"
  },
  "r157": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=121645371&loc=d3e27161-111563"
  },
  "r158": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=121645371&loc=d3e27198-111563"
  },
  "r159": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=121645371&loc=d3e27232-111563"
  },
  "r16": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(28))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r160": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=121645371&loc=SL120269820-111563"
  },
  "r161": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=121645371&loc=d3e27290-111563"
  },
  "r162": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=121645371&loc=d3e27337-111563"
  },
  "r163": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=121645371&loc=d3e27340-111563"
  },
  "r164": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)-(d)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=121645371&loc=d3e27357-111563"
  },
  "r165": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "320",
   "URI": "http://asc.fasb.org/topic&trid=2196928"
  },
  "r166": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "323",
   "URI": "http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571"
  },
  "r167": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121646688&loc=SL121648383-210437"
  },
  "r168": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121646688&loc=SL121648383-210437"
  },
  "r169": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121646688&loc=SL121648383-210437"
  },
  "r17": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(29))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r170": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121646688&loc=SL121648383-210437"
  },
  "r171": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(e)(3)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121646688&loc=SL121648383-210437"
  },
  "r172": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(e)(4)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121646688&loc=SL121648383-210437"
  },
  "r173": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121599337&loc=SL82919244-210447"
  },
  "r174": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121599337&loc=SL82919249-210447"
  },
  "r175": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121599337&loc=SL82919253-210447"
  },
  "r176": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121599337&loc=SL82919258-210447"
  },
  "r177": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121599337&loc=SL82919230-210447"
  },
  "r178": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121558606&loc=SL82898722-210454"
  },
  "r179": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121582814&loc=SL82922888-210455"
  },
  "r18": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(3))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r180": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121582814&loc=SL82922895-210455"
  },
  "r181": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121582814&loc=SL82922900-210455"
  },
  "r182": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456"
  },
  "r183": {
   "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"
  },
  "r184": {
   "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"
  },
  "r185": {
   "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"
  },
  "r186": {
   "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"
  },
  "r187": {
   "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"
  },
  "r188": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229"
  },
  "r189": {
   "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"
  },
  "r19": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(30)(a)(1))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r190": {
   "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"
  },
  "r191": {
   "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"
  },
  "r192": {
   "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"
  },
  "r193": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "440",
   "URI": "http://asc.fasb.org/extlink&oid=121559207&loc=d3e25336-109308"
  },
  "r194": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "440",
   "URI": "http://asc.fasb.org/extlink&oid=121559207&loc=d3e25336-109308"
  },
  "r195": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "440",
   "URI": "http://asc.fasb.org/topic&trid=2144648"
  },
  "r196": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349"
  },
  "r197": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "450",
   "URI": "http://asc.fasb.org/topic&trid=2127136"
  },
  "r198": {
   "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"
  },
  "r199": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=6802200&loc=SL6230698-112601"
  },
  "r2": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=121566466&loc=d3e6676-107765"
  },
  "r20": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(30)(a)(3))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r200": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(1)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870"
  },
  "r201": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(2)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870"
  },
  "r202": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(3)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870"
  },
  "r203": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "470",
   "URI": "http://asc.fasb.org/extlink&oid=120520924&loc=SL6036836-161870"
  },
  "r204": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "470",
   "URI": "http://asc.fasb.org/topic&trid=2208564"
  },
  "r205": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(CFRR 211.02)",
   "Topic": "480",
   "URI": "http://asc.fasb.org/extlink&oid=65877616&loc=d3e177068-122764"
  },
  "r206": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=65888546&loc=d3e21300-112643"
  },
  "r207": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21553-112644"
  },
  "r208": {
   "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"
  },
  "r209": {
   "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"
  },
  "r21": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(30)(a)(4))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r210": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21484-112644"
  },
  "r211": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=109259400&loc=d3e21488-112644"
  },
  "r212": {
   "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"
  },
  "r213": {
   "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"
  },
  "r214": {
   "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"
  },
  "r215": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.3-04)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770"
  },
  "r216": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=121604090&loc=SL49130543-203045"
  },
  "r217": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=121604090&loc=SL49130545-203045"
  },
  "r218": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "91",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=121551570&loc=SL49130690-203046-203046"
  },
  "r219": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(i)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r22": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(30))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r220": {
   "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"
  },
  "r221": {
   "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"
  },
  "r222": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(02)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r223": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(02)(A)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r224": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(02)(B)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r225": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(02)(C)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r226": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)(iv)(03)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920"
  },
  "r227": {
   "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"
  },
  "r228": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(d)",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947"
  },
  "r229": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "80",
   "Topic": "715",
   "URI": "http://asc.fasb.org/extlink&oid=35742348&loc=SL14450788-114948"
  },
  "r23": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(31))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r230": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "35",
   "SubTopic": "10",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121326096&loc=d3e4534-113899"
  },
  "r231": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901"
  },
  "r232": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901"
  },
  "r233": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901"
  },
  "r234": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(3)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r235": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a),(g)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r236": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r237": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r238": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(i)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r239": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(i)-(ii)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r24": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(32))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r240": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(iv)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r241": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(iv)(3)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r242": {
   "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=120381028&loc=d3e5070-113901"
  },
  "r243": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r244": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)(i)-(ii)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r245": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)(iii)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r246": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)(iii)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r247": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)(iii)(3)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r248": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r249": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r25": {
   "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=120391452&loc=d3e13212-122682"
  },
  "r250": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r251": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r252": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r253": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)(2)(i)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r254": {
   "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=120381028&loc=d3e5070-113901"
  },
  "r255": {
   "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=120381028&loc=d3e5070-113901"
  },
  "r256": {
   "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=120381028&loc=d3e5070-113901"
  },
  "r257": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(g)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r258": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r259": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)(1)(i)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r26": {
   "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=120391452&loc=d3e13212-122682"
  },
  "r260": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)(1)(ii)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r261": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(i)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r262": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901"
  },
  "r263": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r264": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r265": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r266": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r267": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r268": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(f)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r269": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(f)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r27": {
   "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=120391452&loc=d3e13212-122682"
  },
  "r270": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(g)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333"
  },
  "r271": {
   "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"
  },
  "r272": {
   "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"
  },
  "r273": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120383193&loc=d3e11149-113907"
  },
  "r274": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=120383193&loc=d3e11178-113907"
  },
  "r275": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "718",
   "URI": "http://asc.fasb.org/topic&trid=2228938"
  },
  "r276": {
   "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"
  },
  "r277": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "740"
  },
  "r278": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "740"
  },
  "r279": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(d)(2)",
   "Topic": "740"
  },
  "r28": {
   "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=120391452&loc=d3e13212-122682"
  },
  "r280": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(d)(3)",
   "Topic": "740"
  },
  "r281": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "31",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "805",
   "URI": "http://asc.fasb.org/extlink&oid=121598580&loc=d3e5419-128473"
  },
  "r282": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "15",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116873149&loc=d3e923-111674"
  },
  "r283": {
   "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"
  },
  "r284": {
   "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"
  },
  "r285": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116870748&loc=SL6758485-165988"
  },
  "r286": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116870748&loc=SL6758485-165988"
  },
  "r287": {
   "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"
  },
  "r288": {
   "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"
  },
  "r289": {
   "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"
  },
  "r29": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(7))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r290": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(bb)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=121559654&loc=d3e5710-111685"
  },
  "r291": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=121559654&loc=d3e5710-111685"
  },
  "r292": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "810",
   "URI": "http://asc.fasb.org/topic&trid=2197479"
  },
  "r293": {
   "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"
  },
  "r294": {
   "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"
  },
  "r295": {
   "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"
  },
  "r296": {
   "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"
  },
  "r297": {
   "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"
  },
  "r298": {
   "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"
  },
  "r299": {
   "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"
  },
  "r3": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=121566466&loc=d3e6676-107765"
  },
  "r30": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(8))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r300": {
   "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"
  },
  "r301": {
   "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"
  },
  "r302": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=121572278&loc=d3e13467-108611"
  },
  "r303": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=121572278&loc=d3e13531-108611"
  },
  "r304": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "21",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=121572278&loc=d3e13537-108611"
  },
  "r305": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "825",
   "URI": "http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612"
  },
  "r306": {
   "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"
  },
  "r307": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32136-110900"
  },
  "r308": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Subparagraph": "(a)",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900"
  },
  "r309": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Subparagraph": "(b)",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900"
  },
  "r31": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.1)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r310": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Subparagraph": "(c)",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900"
  },
  "r311": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Subparagraph": "(d)",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900"
  },
  "r312": {
   "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"
  },
  "r313": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=6450520&loc=d3e32618-110901"
  },
  "r314": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=119993939&loc=d3e28541-108399"
  },
  "r315": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "835",
   "URI": "http://asc.fasb.org/extlink&oid=119993939&loc=d3e28555-108399"
  },
  "r316": {
   "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"
  },
  "r317": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "20",
   "Topic": "840",
   "URI": "http://asc.fasb.org/extlink&oid=121549951&loc=d3e40010-112707"
  },
  "r318": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "25",
   "SubTopic": "20",
   "Topic": "840",
   "URI": "http://asc.fasb.org/extlink&oid=121549951&loc=d3e40019-112707"
  },
  "r319": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=121329987&loc=SL77916155-209984"
  },
  "r32": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.13)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r320": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=121603541&loc=SL77918627-209977"
  },
  "r321": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=121603541&loc=SL77918627-209977"
  },
  "r322": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=121603541&loc=SL77918643-209977"
  },
  "r323": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(3)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=121609121&loc=SL77918673-209980"
  },
  "r324": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=121609121&loc=SL77918673-209980"
  },
  "r325": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=121609121&loc=SL77918686-209980"
  },
  "r326": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(d)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=121609121&loc=SL77918686-209980"
  },
  "r327": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(1)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=121609121&loc=SL77918686-209980"
  },
  "r328": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(2)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=121609121&loc=SL77918686-209980"
  },
  "r329": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(3)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=121609121&loc=SL77918686-209980"
  },
  "r33": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.14)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r330": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(4)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=121609121&loc=SL77918686-209980"
  },
  "r331": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=121609121&loc=SL77918701-209980"
  },
  "r332": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "53",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=121568110&loc=SL77918982-209971"
  },
  "r333": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "850",
   "URI": "http://asc.fasb.org/extlink&oid=6457730&loc=d3e39599-107864"
  },
  "r334": {
   "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"
  },
  "r335": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(2)(i)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r336": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(2)(ii)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r337": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r338": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r339": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r34": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.17)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r340": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r341": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r342": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r343": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719"
  },
  "r344": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719"
  },
  "r345": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719"
  },
  "r346": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719"
  },
  "r347": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719"
  },
  "r348": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=66007379&loc=d3e113888-111728"
  },
  "r349": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=109249958&loc=SL34722452-111729"
  },
  "r35": {
   "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=120391452&loc=d3e13212-122682"
  },
  "r350": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122625-111746"
  },
  "r351": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122625-111746"
  },
  "r352": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122625-111746"
  },
  "r353": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(4)(i)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122625-111746"
  },
  "r354": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122739-111746"
  },
  "r355": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122739-111746"
  },
  "r356": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122739-111746"
  },
  "r357": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(4)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122739-111746"
  },
  "r358": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(5)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122739-111746"
  },
  "r359": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(6)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122739-111746"
  },
  "r36": {
   "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=120391452&loc=d3e13212-122682"
  },
  "r360": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(a)(7)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122739-111746"
  },
  "r361": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(b)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122739-111746"
  },
  "r362": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(e)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122739-111746"
  },
  "r363": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(e)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122739-111746"
  },
  "r364": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "50",
   "Subparagraph": "(e)(3)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=116651436&loc=d3e122739-111746"
  },
  "r365": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "910",
   "URI": "http://asc.fasb.org/extlink&oid=119991564&loc=SL119991595-234733"
  },
  "r366": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 11.L)",
   "Topic": "924",
   "URI": "http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856"
  },
  "r367": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "926",
   "URI": "http://asc.fasb.org/extlink&oid=120154696&loc=d3e54445-107959"
  },
  "r368": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "926",
   "URI": "http://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079"
  },
  "r369": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "926",
   "URI": "http://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079"
  },
  "r37": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.19-26)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r370": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "926",
   "URI": "http://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079"
  },
  "r371": {
   "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"
  },
  "r372": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "320",
   "Topic": "940",
   "URI": "http://asc.fasb.org/extlink&oid=35711157&loc=d3e42546-110969"
  },
  "r373": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "320",
   "Topic": "940",
   "URI": "http://asc.fasb.org/subtopic&trid=2176304"
  },
  "r374": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(11))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r375": {
   "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=120398452&loc=d3e534808-122878"
  },
  "r376": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(23))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r377": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(6))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r378": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.17)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878"
  },
  "r379": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(22))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r38": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.20)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r380": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(26))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r381": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.13)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r382": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.14)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260"
  },
  "r383": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Subparagraph": "(b)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120252992&loc=d3e62557-112803"
  },
  "r384": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120252992&loc=d3e62557-112803"
  },
  "r385": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "320",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=120252992&loc=d3e62586-112803"
  },
  "r386": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "320",
   "Topic": "942",
   "URI": "http://asc.fasb.org/subtopic&trid=2209399"
  },
  "r387": {
   "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"
  },
  "r388": {
   "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=120400017&loc=d3e572229-122910"
  },
  "r389": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(12))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r39": {
   "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=120391452&loc=d3e13212-122682"
  },
  "r390": {
   "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=120400017&loc=d3e572229-122910"
  },
  "r391": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(23)(a)(3))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r392": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(23)(a)(4))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r393": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(25))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r394": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(5))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r395": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(8))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r396": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03.(a),19)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910"
  },
  "r397": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(18))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r398": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(22))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263"
  },
  "r399": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "40",
   "Subparagraph": "(d)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=121643868&loc=SL117782755-158439"
  },
  "r4": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=121566466&loc=d3e6676-107765"
  },
  "r40": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.22(a)(1))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r400": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13H",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "40",
   "Subparagraph": "(c)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=121639165&loc=SL117783719-158441"
  },
  "r401": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "29F",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "40",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=121639165&loc=SL117819544-158441"
  },
  "r402": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(a)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641"
  },
  "r403": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(b)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641"
  },
  "r404": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(e)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641"
  },
  "r405": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(f)(1)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641"
  },
  "r406": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(f)(2)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641"
  },
  "r407": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(g)(1)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641"
  },
  "r408": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(g)(2)(i)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641"
  },
  "r409": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(g)(2)(ii)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641"
  },
  "r41": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.22(b))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r410": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(g)(2)(iii)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641"
  },
  "r411": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(g)(2)(iv)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641"
  },
  "r412": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(h)(1)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641"
  },
  "r413": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(h)(2)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641"
  },
  "r414": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "80",
   "Subparagraph": "(e)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=121641442&loc=d3e19393-158473"
  },
  "r415": {
   "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"
  },
  "r416": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=66023616&loc=SL35737432-115832"
  },
  "r417": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.6-06(3))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=120401414&loc=d3e604059-122996"
  },
  "r418": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "320",
   "Topic": "946",
   "URI": "http://asc.fasb.org/subtopic&trid=2324412"
  },
  "r419": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "210",
   "Topic": "954",
   "URI": "http://asc.fasb.org/extlink&oid=120413173&loc=SL116631458-115580"
  },
  "r42": {
   "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=120391452&loc=d3e13212-122682"
  },
  "r420": {
   "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"
  },
  "r421": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b"
  },
  "r422": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "d1-1"
  },
  "r423": {
   "Name": "Form 10-Q",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "308",
   "Subsection": "a"
  },
  "r424": {
   "Name": "Forms 10-K, 10-Q, 20-F",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "13",
   "Subsection": "a-1"
  },
  "r425": {
   "Name": "Regulation 12B",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b-2"
  },
  "r426": {
   "Name": "Regulation S-T",
   "Number": "232",
   "Publisher": "SEC",
   "Section": "405"
  },
  "r43": {
   "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=120391452&loc=d3e13212-122682"
  },
  "r44": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.25)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r45": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.28,29)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r46": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.29-31)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r47": {
   "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=120391452&loc=d3e13212-122682"
  },
  "r48": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.6(a)(3))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682"
  },
  "r49": {
   "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=120391452&loc=d3e13212-122682"
  },
  "r5": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=121566466&loc=d3e6801-107765"
  },
  "r50": {
   "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=120391452&loc=d3e13212-122682"
  },
  "r51": {
   "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=120391452&loc=d3e13212-122682"
  },
  "r52": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "16",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=99393222&loc=SL20226024-175313"
  },
  "r53": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "210",
   "URI": "http://asc.fasb.org/topic&trid=2122208"
  },
  "r54": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=121641772&loc=SL7669646-108580"
  },
  "r55": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=121641772&loc=SL7669646-108580"
  },
  "r56": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=121641772&loc=SL7669646-108580"
  },
  "r57": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=121641772&loc=d3e637-108580"
  },
  "r58": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=121641772&loc=d3e681-108580"
  },
  "r59": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=121641772&loc=SL7669686-108580"
  },
  "r6": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=121566466&loc=d3e6812-107765"
  },
  "r60": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=121641772&loc=SL34724394-108580"
  },
  "r61": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=121641772&loc=SL7669619-108580"
  },
  "r62": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=121641772&loc=SL7669619-108580"
  },
  "r63": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=121641772&loc=SL7669619-108580"
  },
  "r64": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=121641772&loc=SL7669625-108580"
  },
  "r65": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=121641772&loc=SL7669625-108580"
  },
  "r66": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=121641772&loc=d3e557-108580"
  },
  "r67": {
   "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=120395209&loc=SL114868664-224227"
  },
  "r68": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(24))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227"
  },
  "r69": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(7)(c))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227"
  },
  "r7": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=121566466&loc=d3e6911-107765"
  },
  "r70": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227"
  },
  "r71": {
   "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=120395209&loc=SL114868664-224227"
  },
  "r72": {
   "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=120395209&loc=SL114868664-224227"
  },
  "r73": {
   "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=120395209&loc=SL114868664-224227"
  },
  "r74": {
   "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=120395209&loc=SL114868664-224227"
  },
  "r75": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=121586364&loc=d3e3213-108585"
  },
  "r76": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585"
  },
  "r77": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585"
  },
  "r78": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=121586364&loc=d3e3367-108585"
  },
  "r79": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "24",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=121586364&loc=d3e3521-108585"
  },
  "r8": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=121566466&loc=d3e6935-107765"
  },
  "r80": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=121586364&loc=d3e3536-108585"
  },
  "r81": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=121586364&loc=d3e3536-108585"
  },
  "r82": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585"
  },
  "r83": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585"
  },
  "r84": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585"
  },
  "r85": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=121586364&loc=d3e3044-108585"
  },
  "r86": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=121583591&loc=d3e4297-108586"
  },
  "r87": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=121583591&loc=d3e4304-108586"
  },
  "r88": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=121583591&loc=d3e4313-108586"
  },
  "r89": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=121583591&loc=d3e4332-108586"
  },
  "r9": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=121566466&loc=d3e7018-107765"
  },
  "r90": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=121583591&loc=SL98516268-108586"
  },
  "r91": {
   "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"
  },
  "r92": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(d))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r93": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(g)(1)(ii))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r94": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.4-08(m)(1)(iii))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690"
  },
  "r95": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "235",
   "URI": "http://asc.fasb.org/topic&trid=2122369"
  },
  "r96": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "23",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=115929471&loc=d3e21914-107793"
  },
  "r97": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "24",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=115929471&loc=d3e21930-107793"
  },
  "r98": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "27",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=115929471&loc=d3e22044-107793"
  },
  "r99": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=115929471&loc=d3e21711-107793"
  }
 },
 "version": "2.1"
}
