{
 "instance": {
  "bpmc-20200506x10q.htm": {
   "axisCustom": 1,
   "axisStandard": 19,
   "contextCount": 165,
   "dts": {
    "calculationLink": {
     "local": [
      "bpmc-20200506_cal.xml"
     ]
    },
    "definitionLink": {
     "local": [
      "bpmc-20200506_def.xml"
     ],
     "remote": [
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-eedm-def-2019-01-31.xml",
      "http://xbrl.fasb.org/srt/2019/elts/srt-eedm1-def-2019-01-31.xml"
     ]
    },
    "inline": {
     "local": [
      "bpmc-20200506x10q.htm"
     ]
    },
    "labelLink": {
     "local": [
      "bpmc-20200506_lab.xml"
     ],
     "remote": [
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-doc-2019-01-31.xml",
      "https://xbrl.sec.gov/dei/2019/dei-doc-2019-01-31.xml"
     ]
    },
    "presentationLink": {
     "local": [
      "bpmc-20200506_pre.xml"
     ]
    },
    "referenceLink": {
     "remote": [
      "https://xbrl.sec.gov/dei/2019/dei-ref-2019-01-31.xml",
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-gaap-ref-2019-01-31.xml"
     ]
    },
    "schema": {
     "local": [
      "bpmc-20200506.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/2019/dei-2019-01-31.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/2019/elts/us-gaap-2019-01-31.xsd",
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-roles-2019-01-31.xsd",
      "http://xbrl.fasb.org/srt/2019/elts/srt-2019-01-31.xsd",
      "http://www.xbrl.org/2006/ref-2006-02-27.xsd",
      "http://xbrl.fasb.org/srt/2019/elts/srt-types-2019-01-31.xsd",
      "http://xbrl.fasb.org/srt/2019/elts/srt-roles-2019-01-31.xsd",
      "https://xbrl.sec.gov/country/2017/country-2017-01-31.xsd",
      "http://xbrl.fasb.org/us-gaap/2019/elts/us-types-2019-01-31.xsd",
      "http://www.xbrl.org/lrr/role/negated-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/2019/elts/us-parts-codification-2019-01-31.xsd"
     ]
    }
   },
   "elementCount": 470,
   "entityCount": 1,
   "hidden": {
    "http://fasb.org/us-gaap/2019-01-31": 10,
    "http://xbrl.sec.gov/dei/2019-01-31": 5,
    "total": 15
   },
   "keyCustom": 56,
   "keyStandard": 289,
   "memberCustom": 18,
   "memberStandard": 31,
   "nsprefix": "bpmc",
   "nsuri": "http://www.blueprintmedicines.com/20200506",
   "report": {
    "R1": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "dei:DocumentType",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "document",
     "isDefault": "true",
     "longName": "00090 - Document - Document and Entity Information",
     "role": "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation",
     "shortName": "Document and Entity Information",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "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": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CashCashEquivalentsAndMarketableSecuritiesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10301 - Disclosure - Cash Equivalents and Investments",
     "role": "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestments",
     "shortName": "Cash Equivalents and Investments",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CashCashEquivalentsAndMarketableSecuritiesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R11": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10401 - Disclosure - Fair Value of Financial Instruments",
     "role": "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstruments",
     "shortName": "Fair Value of Financial Instruments",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueDisclosuresTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R12": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AllowanceForCreditLossesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10501 - Disclosure - Product Revenue Reserves and Allowances",
     "role": "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowances",
     "shortName": "Product Revenue Reserves and Allowances",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AllowanceForCreditLossesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R13": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InventoryDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10601 - Disclosure - Inventory",
     "role": "http://www.blueprintmedicines.com/role/DisclosureInventory",
     "shortName": "Inventory",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:InventoryDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R14": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RestrictedAssetsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10701 - Disclosure - Restricted Cash",
     "role": "http://www.blueprintmedicines.com/role/DisclosureRestrictedCash",
     "shortName": "Restricted Cash",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:RestrictedAssetsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R15": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10801 - Disclosure - Property and Equipment, Net",
     "role": "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNet",
     "shortName": "Property and Equipment, Net",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R16": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10901 - Disclosure - Accrued Expenses",
     "role": "http://www.blueprintmedicines.com/role/DisclosureAccruedExpenses",
     "shortName": "Accrued Expenses",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R17": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CollaborativeArrangementDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11001 - Disclosure - Collaboration and License Agreements",
     "role": "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreements",
     "shortName": "Collaboration and License Agreements",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CollaborativeArrangementDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R18": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11101 - Disclosure - Stock-based Compensation",
     "role": "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation",
     "shortName": "Stock-based Compensation",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R19": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EarningsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11201 - Disclosure - Net Loss per Share",
     "role": "http://www.blueprintmedicines.com/role/DisclosureNetLossPerShare",
     "shortName": "Net Loss per Share",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:EarningsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R2": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:CashAndCashEquivalentsAtCarryingValue",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00100 - Statement - Condensed Consolidated Balance Sheets",
     "role": "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets",
     "shortName": "Condensed Consolidated Balance Sheets",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:AvailableForSaleSecuritiesDebtSecuritiesCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R20": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:IncomeTaxDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11301 - Disclosure - Income Taxes",
     "role": "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxes",
     "shortName": "Income Taxes",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:IncomeTaxDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R21": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LesseeOperatingLeasesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11401 - Disclosure - Leases",
     "role": "http://www.blueprintmedicines.com/role/DisclosureLeases",
     "shortName": "Leases",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LesseeOperatingLeasesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R22": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommitmentsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11501 - Disclosure - Commitments",
     "role": "http://www.blueprintmedicines.com/role/DisclosureCommitments",
     "shortName": "Commitments",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:CommitmentsDisclosureTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R23": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SubsequentEventsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "11601 - Disclosure - Subsequent Events",
     "role": "http://www.blueprintmedicines.com/role/DisclosureSubsequentEvents",
     "shortName": "Subsequent Events",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:SubsequentEventsTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R24": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:OrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BasisOfAccountingPolicyPolicyTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "20202 - Disclosure - Summary of Significant Accounting Policies and Recent Accounting Pronouncements (Policies)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsPolicies",
     "shortName": "Summary of Significant Accounting Policies and Recent Accounting Pronouncements (Policies)",
     "subGroupType": "policies",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:OrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:BasisOfAccountingPolicyPolicyTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R25": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:CashCashEquivalentsAndMarketableSecuritiesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfCashCashEquivalentsAndShortTermInvestmentsTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30303 - Disclosure - Cash Equivalents and Investments (Tables)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTables",
     "shortName": "Cash Equivalents and Investments (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:CashCashEquivalentsAndMarketableSecuritiesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfCashCashEquivalentsAndShortTermInvestmentsTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R26": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:FairValueDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30403 - Disclosure - Fair Value of Financial Instruments (Tables)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsTables",
     "shortName": "Fair Value of Financial Instruments (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:FairValueDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R27": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ContractWithCustomerAssetAllowanceForCreditLossTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30503 - Disclosure - Product Revenue Reserves and Allowances (Tables)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesTables",
     "shortName": "Product Revenue Reserves and Allowances (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ContractWithCustomerAssetAllowanceForCreditLossTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R28": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:InventoryDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfInventoryCurrentTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30603 - Disclosure - Inventory (Tables)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureInventoryTables",
     "shortName": "Inventory (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:InventoryDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfInventoryCurrentTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R29": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PropertyPlantAndEquipmentTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30803 - Disclosure - Property and Equipment, Net (Tables)",
     "role": "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetTables",
     "shortName": "Property and Equipment, Net (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PropertyPlantAndEquipmentTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R3": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:PreferredStockParOrStatedValuePerShare",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Divide_USD_shares_gnhcCEo3e0CLqZSFenLTkQ",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00105 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)",
     "role": "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical",
     "shortName": "Condensed Consolidated Balance Sheets (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:PreferredStockParOrStatedValuePerShare",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Divide_USD_shares_gnhcCEo3e0CLqZSFenLTkQ",
      "xsiNil": "false"
     }
    },
    "R30": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAccruedLiabilitiesTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "30903 - Disclosure - Accrued Expenses (Tables)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesTables",
     "shortName": "Accrued Expenses (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAccruedLiabilitiesTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R31": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "bpmc:ScheduleOfManufacturingServicesRelatedToAgreementActivitiesTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31003 - Disclosure - Collaboration and License Agreements (Tables)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsTables",
     "shortName": "Collaboration and License Agreements (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "bpmc:ScheduleOfManufacturingServicesRelatedToAgreementActivitiesTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R32": {
     "firstAnchor": {
      "ancestors": [
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31103 - Disclosure - Stock-based Compensation (Tables)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationTables",
     "shortName": "Stock-based Compensation (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R33": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31203 - Disclosure - Net Loss per Share (Tables)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureNetLossPerShareTables",
     "shortName": "Net Loss per Share (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R34": {
     "firstAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LeaseCostTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "31403 - Disclosure - Leases (Tables)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureLeasesTables",
     "shortName": "Leases (Tables)",
     "subGroupType": "tables",
     "uniqueAnchor": {
      "ancestors": [
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:LeaseCostTableTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R35": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "p",
       "us-gaap:NatureOfOperations",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_27_2020_To_1_27_2020_us-gaap_SubsidiarySaleOfStockAxis_bpmc_FollowOnOfferingMember_CyTAaahMI0uRl8t89o4a8Q",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:StockIssuedDuringPeriodSharesNewIssues",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_MVEy_Y4dJUqk3QqM6BK3WA",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40101 - Disclosure - Nature of Business - Sale of Stock (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureNatureOfBusinessSaleOfStockDetails",
     "shortName": "Nature of Business - Sale of Stock (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "p",
       "us-gaap:NatureOfOperations",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_27_2020_To_1_27_2020_us-gaap_SubsidiarySaleOfStockAxis_bpmc_FollowOnOfferingMember_CyTAaahMI0uRl8t89o4a8Q",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:StockIssuedDuringPeriodSharesNewIssues",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_MVEy_Y4dJUqk3QqM6BK3WA",
      "xsiNil": "false"
     }
    },
    "R36": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "p",
       "us-gaap:NatureOfOperations",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:CashCashEquivalentsAndShortTermInvestments",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40102 - Disclosure - Nature of Business - Cash, Cash Equivalents and Investments (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureNatureOfBusinessCashCashEquivalentsAndInvestmentsDetails",
     "shortName": "Nature of Business - Cash, Cash Equivalents and Investments (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "p",
       "us-gaap:NatureOfOperations",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:CashCashEquivalentsAndShortTermInvestments",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R37": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:NewAccountingPronouncementsPolicyPolicyTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_us-gaap_AccountingStandardsUpdate201613Member_BXftWYVW4Uu91C2dg5mQFA",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ChangeInAccountingPrincipleAccountingStandardsUpdateAdopted",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40202 - Disclosure - Summary of Significant Accounting Policies and Recent Accounting Pronouncements - New Accounting Pronouncements (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNewAccountingPronouncementsDetails",
     "shortName": "Summary of Significant Accounting Policies and Recent Accounting Pronouncements - New Accounting Pronouncements (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:NewAccountingPronouncementsPolicyPolicyTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_us-gaap_AccountingStandardsUpdate201613Member_BXftWYVW4Uu91C2dg5mQFA",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:ChangeInAccountingPrincipleAccountingStandardsUpdateAdopted",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R38": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfCashCashEquivalentsAndShortTermInvestmentsTableTextBlock",
       "us-gaap:CashCashEquivalentsAndMarketableSecuritiesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020_us-gaap_CashAndCashEquivalentsAxis_us-gaap_MoneyMarketFundsMember_3nERN8MhbUOgf1V8VkwVFQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:CashEquivalentsAtCarryingValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40301 - Disclosure - Cash Equivalents and Investments - Tabular Disclosure - Cash Equivalents (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureCashEquivalentsDetails",
     "shortName": "Cash Equivalents and Investments - Tabular Disclosure - Cash Equivalents (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfCashCashEquivalentsAndShortTermInvestmentsTableTextBlock",
       "us-gaap:CashCashEquivalentsAndMarketableSecuritiesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020_us-gaap_CashAndCashEquivalentsAxis_us-gaap_MoneyMarketFundsMember_3nERN8MhbUOgf1V8VkwVFQ",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:CashEquivalentsAtCarryingValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R39": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfCashCashEquivalentsAndShortTermInvestmentsTableTextBlock",
       "us-gaap:CashCashEquivalentsAndMarketableSecuritiesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020_us-gaap_InvestmentTypeAxis_us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember_12Udkoo-mkKI8GCn1zRf2Q",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40302 - Disclosure - Cash Equivalents and Investments - Tabular Disclosure - Investments, Available-for-sale (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureInvestmentsAvailableForSaleDetails",
     "shortName": "Cash Equivalents and Investments - Tabular Disclosure - Investments, Available-for-sale (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfCashCashEquivalentsAndShortTermInvestmentsTableTextBlock",
       "us-gaap:CashCashEquivalentsAndMarketableSecuritiesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020_us-gaap_InvestmentTypeAxis_us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember_12Udkoo-mkKI8GCn1zRf2Q",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R4": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00200 - Statement - Condensed Consolidated Statements of Operations and Comprehensive Loss",
     "role": "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss",
     "shortName": "Condensed Consolidated Statements of Operations and Comprehensive Loss",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:CostOfGoodsAndServicesSold",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R40": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfCashCashEquivalentsAndShortTermInvestmentsTableTextBlock",
       "us-gaap:CashCashEquivalentsAndMarketableSecuritiesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "bpmc:CashEquivalentAndAvailableForSaleDebtSecuritiesAmortizedCostBasis",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40303 - Disclosure - Cash Equivalents and Investments - Tabular Disclosure - Total (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureTotalDetails",
     "shortName": "Cash Equivalents and Investments - Tabular Disclosure - Total (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfCashCashEquivalentsAndShortTermInvestmentsTableTextBlock",
       "us-gaap:CashCashEquivalentsAndMarketableSecuritiesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "bpmc:CashEquivalentAndAvailableForSaleDebtSecuritiesAmortizedCostBasis",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R41": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_security_qgh3n5FOIkq1q_LgJmX9sg",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40304 - Disclosure - Cash Equivalents and Investments - Unrealized Loss Position (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsUnrealizedLossPositionDetails",
     "shortName": "Cash Equivalents and Investments - Unrealized Loss Position (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_security_qgh3n5FOIkq1q_LgJmX9sg",
      "xsiNil": "false"
     }
    },
    "R42": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "bpmc:DebtSecuritiesAvailableForSaleNumberOfPositions",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_security_qgh3n5FOIkq1q_LgJmX9sg",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40305 - Disclosure - Cash Equivalents and Investments - Remaining Maturities (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsRemainingMaturitiesDetails",
     "shortName": "Cash Equivalents and Investments - Remaining Maturities (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "bpmc:DebtSecuritiesAvailableForSaleNumberOfPositions",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_security_qgh3n5FOIkq1q_LgJmX9sg",
      "xsiNil": "false"
     }
    },
    "R43": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfCashCashEquivalentsAndShortTermInvestmentsTableTextBlock",
       "us-gaap:CashCashEquivalentsAndMarketableSecuritiesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020_us-gaap_InvestmentTypeAxis_us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember_12Udkoo-mkKI8GCn1zRf2Q",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:AvailableForSaleSecuritiesDebtSecurities",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40401 - Disclosure - Fair Value of Financial Instruments (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails",
     "shortName": "Fair Value of Financial Instruments (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTableTextBlock",
       "us-gaap:FairValueDisclosuresTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020_us-gaap_FairValueByMeasurementFrequencyAxis_us-gaap_FairValueMeasurementsRecurringMember_z4hYXfJP30GyhC_wieLTQg",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:AssetsFairValueDisclosure",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R44": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40501 - Disclosure - Product Revenue Reserves and Allowances - Product Revenue (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueDetails",
     "shortName": "Product Revenue Reserves and Allowances - Product Revenue (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R45": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ContractWithCustomerAssetAllowanceForCreditLossTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_12_31_2019_RuYo_-Z4jEiLNdjHJNmffw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40502 - Disclosure - Product Revenue Reserves and Allowances - Product Revenue Allowance - Roll Forward (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueAllowanceRollForwardDetails",
     "shortName": "Product Revenue Reserves and Allowances - Product Revenue Allowance - Roll Forward (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ContractWithCustomerAssetAllowanceForCreditLossTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:ContractWithCustomerAssetCreditLossExpense",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R46": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ContractWithCustomerAssetAllowanceForCreditLossTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40503 - Disclosure - Product Revenue Reserves and Allowances - Product Revenue Allowance - Location (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueAllowanceLocationDetails",
     "shortName": "Product Revenue Reserves and Allowances - Product Revenue Allowance - Location (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ContractWithCustomerAssetAllowanceForCreditLossTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020_us-gaap_BalanceSheetLocationAxis_us-gaap_AccountsReceivableMember_KHsjIABC0kyBk1UBK2gYNw",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R47": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfInventoryCurrentTableTextBlock",
       "us-gaap:InventoryDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:InventoryWorkInProcessNetOfReserves",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40601 - Disclosure - Inventory - Capitalized (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureInventoryCapitalizedDetails",
     "shortName": "Inventory - Capitalized (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfInventoryCurrentTableTextBlock",
       "us-gaap:InventoryDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:InventoryWorkInProcessNetOfReserves",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R48": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:InventoryDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "0",
      "first": true,
      "lang": null,
      "name": "us-gaap:InventoryWriteDown",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40602 - Disclosure - Inventory - Write-down (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureInventoryWriteDownDetails",
     "shortName": "Inventory - Write-down (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:InventoryDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "0",
      "first": true,
      "lang": null,
      "name": "us-gaap:InventoryWriteDown",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R49": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:RestrictedAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:RestrictedCash",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40701 - Disclosure - Restricted Cash (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureRestrictedCashDetails",
     "shortName": "Restricted Cash (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R5": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_12_31_2018_us-gaap_StatementEquityComponentsAxis_us-gaap_CommonStockMember_l599zzukzUG2RUH1FgAlxw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:StockholdersEquity",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00300 - Statement - Condensed Consolidated Statements of Stockholders' Equity",
     "role": "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity",
     "shortName": "Condensed Consolidated Statements of Stockholders' Equity",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_12_31_2018_us-gaap_StatementEquityComponentsAxis_us-gaap_CommonStockMember_l599zzukzUG2RUH1FgAlxw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:StockholdersEquity",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R50": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:PropertyPlantAndEquipmentTextBlock",
       "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_us-gaap_PropertyPlantAndEquipmentByTypeAxis_us-gaap_EquipmentMember_Ew7Fv_MOJUWVYQPn0k27HQ",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PropertyPlantAndEquipmentUsefulLife",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40801 - Disclosure - Property and Equipment, Net - Estimated Useful Lives (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetEstimatedUsefulLivesDetails",
     "shortName": "Property and Equipment, Net - Estimated Useful Lives (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:PropertyPlantAndEquipmentTextBlock",
       "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_us-gaap_PropertyPlantAndEquipmentByTypeAxis_us-gaap_EquipmentMember_Ew7Fv_MOJUWVYQPn0k27HQ",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:PropertyPlantAndEquipmentUsefulLife",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R51": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:PropertyPlantAndEquipmentTextBlock",
       "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:PropertyPlantAndEquipmentGross",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40802 - Disclosure - Property and Equipment, Net - Property and Equipment and Related Accumulated Depreciation (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails",
     "shortName": "Property and Equipment, Net - Property and Equipment and Related Accumulated Depreciation (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:PropertyPlantAndEquipmentTextBlock",
       "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:PropertyPlantAndEquipmentGross",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R52": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:Depreciation",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40803 - Disclosure - Property and Equipment, Net - Depreciation Expense (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetDepreciationExpenseDetails",
     "shortName": "Property and Equipment, Net - Depreciation Expense (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:PropertyPlantAndEquipmentDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:Depreciation",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R53": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfAccruedLiabilitiesTableTextBlock",
       "us-gaap:AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "bpmc:ExternalResearchDevelopmentAndCommercialContractCostsCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "40901 - Disclosure - Accrued Expenses (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesDetails",
     "shortName": "Accrued Expenses (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfAccruedLiabilitiesTableTextBlock",
       "us-gaap:AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "bpmc:ExternalResearchDevelopmentAndCommercialContractCostsCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R54": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41001 - Disclosure - Collaboration and License Agreements - General Information (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails",
     "shortName": "Collaboration and License Agreements - General Information (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020_srt_CounterpartyNameAxis_bpmc_RocheMember_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_bpmc_cnst_2019-07-01_PloNyEP0D0SrYGoUliRRNQ",
      "decimals": null,
      "lang": "en-US",
      "name": "us-gaap:RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R55": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "bpmc:ScheduleOfManufacturingServicesRelatedToAgreementActivitiesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_srt_CounterpartyNameAxis_bpmc_CStoneMember_us-gaap_TypeOfArrangementAxis_bpmc_CollaborativeArrangementGlobalDevelopmentOfLicensedProductMember_GJdtiIBvDUC9CWBW_bMYVw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "bpmc:ManufacturingServicesRelatedToAgreementActivities",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41002 - Disclosure - Collaboration and License Agreements - Manufacturing Services (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsManufacturingServicesDetails",
     "shortName": "Collaboration and License Agreements - Manufacturing Services (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "bpmc:ScheduleOfManufacturingServicesRelatedToAgreementActivitiesTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_srt_CounterpartyNameAxis_bpmc_CStoneMember_us-gaap_TypeOfArrangementAxis_bpmc_CollaborativeArrangementGlobalDevelopmentOfLicensedProductMember_GJdtiIBvDUC9CWBW_bMYVw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "bpmc:ManufacturingServicesRelatedToAgreementActivities",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R56": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41003 - Disclosure - Collaboration and License Agreements - Revenue Recognized - CStone (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedCstoneDetails",
     "shortName": "Collaboration and License Agreements - Revenue Recognized - CStone (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:DisaggregationOfRevenueTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_srt_CounterpartyNameAxis_bpmc_CStoneMember_us-gaap_TypeOfArrangementAxis_us-gaap_CollaborativeArrangementMember_sGm-SlqOzUmIeL5ez4yp4g",
      "decimals": "-3",
      "lang": null,
      "name": "bpmc:LicenseMilestoneRevenue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R57": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:AccountsReceivableNetCurrent",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41004 - Disclosure - Collaboration and License Agreements - Contract Assets - CStone (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsContractAssetsCstoneDetails",
     "shortName": "Collaboration and License Agreements - Contract Assets - CStone (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ContractWithCustomerAssetAndLiabilityTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020_srt_CounterpartyNameAxis_bpmc_CStoneMember_us-gaap_TypeOfArrangementAxis_us-gaap_CollaborativeArrangementMember_8HaZXBVTUUWhhHqGgeXreQ",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:AccountsReceivableNetCurrent",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R58": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41005 - Disclosure - Collaboration and License Agreements - Revenue Recognized - Roche (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedRocheDetails",
     "shortName": "Collaboration and License Agreements - Revenue Recognized - Roche (Details)",
     "subGroupType": "details",
     "uniqueAnchor": null
    },
    "R59": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_4_8_2015_us-gaap_PlanNameAxis_bpmc_StockOptionAndIncentivePlan2015Member_W1fx4sjAY0CuZqqs0cmXWg",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_MVEy_Y4dJUqk3QqM6BK3WA",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41101 - Disclosure - Stock-based Compensation - 2015 Stock Option and Incentive Plan (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2015StockOptionAndIncentivePlanDetails",
     "shortName": "Stock-based Compensation - 2015 Stock Option and Incentive Plan (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_4_8_2015_us-gaap_PlanNameAxis_bpmc_StockOptionAndIncentivePlan2015Member_W1fx4sjAY0CuZqqs0cmXWg",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_MVEy_Y4dJUqk3QqM6BK3WA",
      "xsiNil": "false"
     }
    },
    "R6": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ProfitLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00400 - Statement - Condensed Consolidated Statements of Cash Flows",
     "role": "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows",
     "shortName": "Condensed Consolidated Statements of Cash Flows",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:ProfitLoss",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R60": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_12_31_2019_RuYo_-Z4jEiLNdjHJNmffw",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_MVEy_Y4dJUqk3QqM6BK3WA",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41102 - Disclosure - Stock-based Compensation - Stock Options (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockOptionsDetails",
     "shortName": "Stock-based Compensation - Stock Options (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_12_31_2019_RuYo_-Z4jEiLNdjHJNmffw",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_MVEy_Y4dJUqk3QqM6BK3WA",
      "xsiNil": "false"
     }
    },
    "R61": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock",
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_12_31_2019_us-gaap_AwardTypeAxis_us-gaap_RestrictedStockUnitsRSUMember_iuQ5169qJE2Drw75hVeE4w",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_MVEy_Y4dJUqk3QqM6BK3WA",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41103 - Disclosure - Stock-based Compensation - Restricted Stock Units (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails",
     "shortName": "Stock-based Compensation - Restricted Stock Units (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock",
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_12_31_2019_us-gaap_AwardTypeAxis_us-gaap_RestrictedStockUnitsRSUMember_iuQ5169qJE2Drw75hVeE4w",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_MVEy_Y4dJUqk3QqM6BK3WA",
      "xsiNil": "false"
     }
    },
    "R62": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41104 - Disclosure - Stock-based Compensation - Unrecognized Compensation Costs (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationUnrecognizedCompensationCostsDetails",
     "shortName": "Stock-based Compensation - Unrecognized Compensation Costs (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R63": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
       "us-gaap:DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross",
      "reportCount": 1,
      "unitRef": "Unit_Standard_shares_MVEy_Y4dJUqk3QqM6BK3WA",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41105 - Disclosure - Stock-based Compensation - 2020 Inducement Plan (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2020InducementPlanDetails",
     "shortName": "Stock-based Compensation - 2020 Inducement Plan (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020_us-gaap_PlanNameAxis_bpmc_InducementPlan2020Member_uKSQr3PXVUeDCYsD-Nd7ww",
      "decimals": "INF",
      "lang": null,
      "name": "us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_MVEy_Y4dJUqk3QqM6BK3WA",
      "xsiNil": "false"
     }
    },
    "R64": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_5_31_2015_us-gaap_AwardTypeAxis_us-gaap_EmployeeStockMember_ozEZd8ZNfEitZb_AfxQqSw",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:CommonStockCapitalSharesReservedForFutureIssuance",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_MVEy_Y4dJUqk3QqM6BK3WA",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41106 - Disclosure - Stock-based Compensation - Employee Stock Purchase Plan (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationEmployeeStockPurchasePlanDetails",
     "shortName": "Stock-based Compensation - Employee Stock Purchase Plan (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_5_31_2015_us-gaap_AwardTypeAxis_us-gaap_EmployeeStockMember_ozEZd8ZNfEitZb_AfxQqSw",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "us-gaap:CommonStockCapitalSharesReservedForFutureIssuance",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_MVEy_Y4dJUqk3QqM6BK3WA",
      "xsiNil": "false"
     }
    },
    "R65": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardCompensationCost1",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41107 - Disclosure - Stock-based Compensation - Stock-based Compensation Expense (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails",
     "shortName": "Stock-based Compensation - Stock-based Compensation Expense (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardCompensationCost1",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R66": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "0",
      "first": true,
      "lang": null,
      "name": "us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_MVEy_Y4dJUqk3QqM6BK3WA",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41201 - Disclosure - Net Loss per Share (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureNetLossPerShareDetails",
     "shortName": "Net Loss per Share (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "0",
      "first": true,
      "lang": null,
      "name": "us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_shares_MVEy_Y4dJUqk3QqM6BK3WA",
      "xsiNil": "false"
     }
    },
    "R67": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:IncomeTaxDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "bpmc:CoronavirusAidReliefAndEconomicSecurityActTaxableIncomeLimitationPercentageEliminated",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_VNjqaQZhi0qN75AFzWX1xQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41301 - Disclosure - Income Taxes (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxesDetails",
     "shortName": "Income Taxes (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:IncomeTaxDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "INF",
      "first": true,
      "lang": null,
      "name": "bpmc:CoronavirusAidReliefAndEconomicSecurityActTaxableIncomeLimitationPercentageEliminated",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_pure_VNjqaQZhi0qN75AFzWX1xQ",
      "xsiNil": "false"
     }
    },
    "R68": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "us-gaap:RestrictedAssetsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:RestrictedCash",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41401 - Disclosure - Leases - General Information (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails",
     "shortName": "Leases - General Information (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "us-gaap:LesseeOperatingLeasesTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_2_12_2015_srt_CounterpartyNameAxis_bpmc_OfficeAndLaboratorySpaceInCambridgeMassachusettsMember_UIwrDcv_NkCoTukZOShM3w",
      "decimals": "0",
      "lang": null,
      "name": "us-gaap:AreaOfRealEstateProperty",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_sqft_lteqqBC6WkmPDuUcdc5Z_w",
      "xsiNil": "false"
     }
    },
    "R69": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:LeaseCostTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:OperatingLeaseCost",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41402 - Disclosure - Leases - Components of Lease Expense (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureLeasesComponentsOfLeaseExpenseDetails",
     "shortName": "Leases - Components of Lease Expense (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "us-gaap:LeaseCostTableTextBlock",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:OperatingLeaseCost",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R7": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:CashAndCashEquivalentsAtCarryingValue",
      "reportCount": 1,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "statement",
     "isDefault": "false",
     "longName": "00405 - Statement - Condensed Consolidated Statements of Cash Flows (Parenthetical)",
     "role": "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlowsParenthetical",
     "shortName": "Condensed Consolidated Statements of Cash Flows (Parenthetical)",
     "subGroupType": "parenthetical",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2019_7A5aSCX_kEGlFHxsRqhVyQ",
      "decimals": "-3",
      "lang": null,
      "name": "us-gaap:CashAndCashEquivalentsAtCarryingValue",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R70": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:OperatingLeasePayments",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41403 - Disclosure - Leases - Cash Flow Information (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureLeasesCashFlowInformationDetails",
     "shortName": "Leases - Cash Flow Information (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": "-3",
      "first": true,
      "lang": null,
      "name": "us-gaap:OperatingLeasePayments",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R71": {
     "firstAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OperatingLeaseWeightedAverageRemainingLeaseTerm1",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41404 - Disclosure - Leases - Weighted Average Remaining Lease-term and Weighted Average Discount Rate (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureLeasesWeightedAverageRemainingLeaseTermAndWeightedAverageDiscountRateDetails",
     "shortName": "Leases - Weighted Average Remaining Lease-term and Weighted Average Discount Rate (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "p",
       "td",
       "tr",
       "table",
       "ix:continuation",
       "ix:continuation",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OperatingLeaseWeightedAverageRemainingLeaseTerm1",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R72": {
     "firstAnchor": {
      "ancestors": [
       "span",
       "p",
       "us-gaap:CommitmentsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:PurchaseObligation",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "41501 - Disclosure - Commitments (Details)",
     "role": "http://www.blueprintmedicines.com/role/DisclosureCommitmentsDetails",
     "shortName": "Commitments (Details)",
     "subGroupType": "details",
     "uniqueAnchor": {
      "ancestors": [
       "span",
       "p",
       "us-gaap:CommitmentsDisclosureTextBlock",
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "As_Of_3_31_2020__rQF0ixqrk-9HXJK1eLQlA",
      "decimals": "-5",
      "first": true,
      "lang": null,
      "name": "us-gaap:PurchaseObligation",
      "reportCount": 1,
      "unique": true,
      "unitRef": "Unit_Standard_USD_LWIUXhFwL0m4eaZdOSL_rQ",
      "xsiNil": "false"
     }
    },
    "R8": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NatureOfOperations",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10101 - Disclosure - Nature of Business",
     "role": "http://www.blueprintmedicines.com/role/DisclosureNatureOfBusiness",
     "shortName": "Nature of Business",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:NatureOfOperations",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    },
    "R9": {
     "firstAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     },
     "groupType": "disclosure",
     "isDefault": "false",
     "longName": "10201 - Disclosure - Summary of Significant Accounting Policies and Recent Accounting Pronouncements",
     "role": "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncements",
     "shortName": "Summary of Significant Accounting Policies and Recent Accounting Pronouncements",
     "subGroupType": "",
     "uniqueAnchor": {
      "ancestors": [
       "div",
       "div",
       "body",
       "html"
      ],
      "baseRef": "bpmc-20200506x10q.htm",
      "contextRef": "Duration_1_1_2020_To_3_31_2020_ruPOlRcWqkSI4ljiVmBeLw",
      "decimals": null,
      "first": true,
      "lang": "en-US",
      "name": "us-gaap:OrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock",
      "reportCount": 1,
      "unique": true,
      "unitRef": null,
      "xsiNil": "false"
     }
    }
   },
   "segmentCount": 53,
   "tag": {
    "bpmc_AccountingStandardsUpdate201912Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Accounting Standards Update 2019-12 Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes.",
        "label": "Accounting Standards Update201912 [Member]",
        "terseLabel": "Accounting Standards Update 2019-12"
       }
      }
     },
     "localname": "AccountingStandardsUpdate201912Member",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNewAccountingPronouncementsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_AccretionOfPremiumsAndDiscountsOnInvestments": {
     "auth_ref": [],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 4.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash inflow from the accretion of premiums and discounts on investments.",
        "label": "Accretion Of Premiums And Discounts On Investments",
        "terseLabel": "Accretion of premiums and discounts on investments"
       }
      }
     },
     "localname": "AccretionOfPremiumsAndDiscountsOnInvestments",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_AccruedContractWithCustomerAssetAccumulatedAllowanceForCreditLoss": {
     "auth_ref": [],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_AccruedLiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of accrued accumulated credit loss for right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.",
        "label": "Accrued Contract With Customer Asset Accumulated Allowance For Credit Loss",
        "terseLabel": "Revenue-related reserves"
       }
      }
     },
     "localname": "AccruedContractWithCustomerAssetAccumulatedAllowanceForCreditLoss",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_AccruedPropertyAndEquipmentCostsCurrent": {
     "auth_ref": [],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesDetails": {
       "order": 5.0,
       "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 property and equipment costs. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
        "label": "Accrued Property and Equipment Costs, Current",
        "terseLabel": "Property and equipment costs"
       }
      }
     },
     "localname": "AccruedPropertyAndEquipmentCostsCurrent",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_AchievedResearchMilestonePaymentReceivedToBeRecognizedOverPerformancePeriod": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the cash inflow from achieved research milestone payment received, which will be recognized as revenue over the period of performance.",
        "label": "Achieved Research Milestone Payment Received To Be Recognized Over Performance Period",
        "terseLabel": "Achieved research milestone payment received which will be recognized over period of performance"
       }
      }
     },
     "localname": "AchievedResearchMilestonePaymentReceivedToBeRecognizedOverPerformancePeriod",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_AdditionalSubleasePaymentsShareOfProfitsLandlord.": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of additional sublease payments on share of profits directly to the landlord.",
        "label": "Additional Sublease payments, Share of Profits, Landlord.",
        "terseLabel": "Additional sublease payments on share of profits"
       }
      }
     },
     "localname": "AdditionalSubleasePaymentsShareOfProfitsLandlord.",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_AnnualCumulativeIncreasePercentageOfNumberOfShareOfCommonStockIssuedAndOutstanding": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the annual cumulative increase for common stock issuance, as a percentage of the number of shares of common stock issued and outstanding.",
        "label": "Annual Cumulative Increase Percentage of Number of Share of Common Stock Issued and Outstanding",
        "terseLabel": "Annual increase for common stock for issuance (as a percent)"
       }
      }
     },
     "localname": "AnnualCumulativeIncreasePercentageOfNumberOfShareOfCommonStockIssuedAndOutstanding",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationEmployeeStockPurchasePlanDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "bpmc_CStoneMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "C Stone [Member]",
        "label": "C Stone [Member]",
        "terseLabel": "C Stone"
       }
      }
     },
     "localname": "CStoneMember",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsContractAssetsCstoneDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsManufacturingServicesDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedCstoneDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_CashEquivalentAndAvailableForSaleDebtSecuritiesAmortizedCostBasis": {
     "auth_ref": [],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureTotalDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the cost of cash equivalents and cost of debt 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": "Cash Equivalent and Available-for-sale Debt Securities, Amortized Cost Basis",
        "totalLabel": "Total, Amortized Cost"
       }
      }
     },
     "localname": "CashEquivalentAndAvailableForSaleDebtSecuritiesAmortizedCostBasis",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureTotalDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_CashEquivalentsAndAvailableForSaleAccumulatedGrossUnrealizedGainBeforeTax": {
     "auth_ref": [],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureTotalDetails": {
       "order": 1.0,
       "parentTag": "bpmc_CashEquivalentAndAvailableForSaleDebtSecuritiesAmortizedCostBasis",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Cash Equivalents and Available-for-sale, Accumulated Gross Unrealized Gain, before Tax",
        "label": "Cash Equivalents and Available-for-sale, Accumulated Gross Unrealized Gain, before Tax",
        "terseLabel": "Total, Unrealized Gain"
       }
      }
     },
     "localname": "CashEquivalentsAndAvailableForSaleAccumulatedGrossUnrealizedGainBeforeTax",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureTotalDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_CashEquivalentsAndAvailableForSaleAccumulatedGrossUnrealizedLossBeforeTax": {
     "auth_ref": [],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureTotalDetails": {
       "order": 2.0,
       "parentTag": "bpmc_CashEquivalentAndAvailableForSaleDebtSecuritiesAmortizedCostBasis",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Cash Equivalents and Available-for-sale, Accumulated Gross Unrealized Loss, before Tax",
        "label": "Cash Equivalents and Available-for-sale, Accumulated Gross Unrealized Loss, before Tax",
        "negatedLabel": "Total, Unrealized Losses"
       }
      }
     },
     "localname": "CashEquivalentsAndAvailableForSaleAccumulatedGrossUnrealizedLossBeforeTax",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureTotalDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_CashEquivalentsAndAvailableForSaleSecuritiesDebtSecuritiesFairValue": {
     "auth_ref": [],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureTotalDetails": {
       "order": 3.0,
       "parentTag": "bpmc_CashEquivalentAndAvailableForSaleDebtSecuritiesAmortizedCostBasis",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the fair value of cash equivalents and amount of debt securities categorized neither as held-to-maturity nor trading.",
        "label": "Cash Equivalents and Available-for-sale Securities, Debt Securities, Fair Value",
        "terseLabel": "Total, Fair Value"
       }
      }
     },
     "localname": "CashEquivalentsAndAvailableForSaleSecuritiesDebtSecuritiesFairValue",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureTotalDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_ClementiaMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Clementia [Member]",
        "label": "Clementia [Member]",
        "terseLabel": "Clementia"
       }
      }
     },
     "localname": "ClementiaMember",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_CollaborationAgreementCashMilestonePaymentsDue": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of cash milestone payments due to be received by the company.",
        "label": "Collaboration Agreement, Cash Milestone Payments Due",
        "terseLabel": "Cash milestone payment"
       }
      }
     },
     "localname": "CollaborationAgreementCashMilestonePaymentsDue",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_CollaborationAgreementMilestoneAndOtherPayments": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of other payments and potential development, regulatory and sales-based milestone payments for licensed products, due to be received by the company.",
        "label": "Collaboration Agreement, Milestone And Other Payments",
        "terseLabel": "Milestone other payment"
       }
      }
     },
     "localname": "CollaborationAgreementMilestoneAndOtherPayments",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_CollaborationAgreementNumberOfPerformanceObligations": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of performance obligations under the collaboration agreement.",
        "label": "Collaboration Agreement, Number Of Performance Obligations",
        "terseLabel": "Number of performance obligations"
       }
      }
     },
     "localname": "CollaborationAgreementNumberOfPerformanceObligations",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "bpmc_CollaborationAgreementPurchaseOfExistingManufacturingInventory": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of purchase of existing manufacturing inventory under the collaboration agreement.",
        "label": "Collaboration Agreement, Purchase Of Existing Manufacturing Inventory",
        "terseLabel": "Purchase of existing manufacturing inventory"
       }
      }
     },
     "localname": "CollaborationAgreementPurchaseOfExistingManufacturingInventory",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_CollaborationAgreementPurchaseOfInProgressManufacturingInventory": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of purchase of in-progress manufacturing inventory under the collaboration agreement.",
        "label": "Collaboration Agreement, Purchase Of In Progress Manufacturing Inventory",
        "terseLabel": "Purchase of in-process manufacturing inventory"
       }
      }
     },
     "localname": "CollaborationAgreementPurchaseOfInProgressManufacturingInventory",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_CollaborationAgreementPurchaseOfManufacturingInventory": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of purchase of manufacturing inventory under the collaboration agreement.",
        "label": "Collaboration Agreement, Purchase Of Manufacturing Inventory",
        "terseLabel": "Purchase specified manufacturing inventory"
       }
      }
     },
     "localname": "CollaborationAgreementPurchaseOfManufacturingInventory",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_CollaborationMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Collaboration [Member]",
        "label": "Collaboration [Member]",
        "terseLabel": "Collaboration revenue"
       }
      }
     },
     "localname": "CollaborationMember",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_CollaborativeArrangementDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Collaborative Arrangement Disclosure [Abstract]",
        "label": "Collaborative Arrangement Disclosure [Abstract]"
       }
      }
     },
     "localname": "CollaborativeArrangementDisclosureAbstract",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "xbrltype": "stringItemType"
    },
    "bpmc_CollaborativeArrangementEligibleContingentOptionFeesAndMilestonePayments": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the aggregate amount of eligible contingent option fees and milestone payments related to specified research, pre-clinical, clinical, regulatory and sales-based milestones.",
        "label": "Collaborative Arrangement Eligible Contingent Option Fees And Milestone Payments",
        "terseLabel": "Total eligible contingent option fees and milestone payments"
       }
      }
     },
     "localname": "CollaborativeArrangementEligibleContingentOptionFeesAndMilestonePayments",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_CollaborativeArrangementEligibleMilestonePayments": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Collaborative Arrangement Eligible Milestone Payments.",
        "label": "Collaborative Arrangement Eligible Milestone Payments",
        "terseLabel": "Eligible milestone payments"
       }
      }
     },
     "localname": "CollaborativeArrangementEligibleMilestonePayments",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_CollaborativeArrangementEligibleOptionFeesAndMilestonePaymentsPriorToLicensingAcrossAllPrograms": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the amount of option fees and milestone payments for research, pre-clinical and clinical development events prior to licensing across all five potential collaboration programs, including contingent milestone payments for initiation of each of the collaboration programs for which the parties will work together to select targets (pre-option exercise milestones).",
        "label": "Collaborative Arrangement Eligible Option Fees And Milestone Payments Prior To Licensing Across All Programs",
        "terseLabel": "Eligible option fees and milestones prior to licensing for all potential collaboration programs"
       }
      }
     },
     "localname": "CollaborativeArrangementEligibleOptionFeesAndMilestonePaymentsPriorToLicensingAcrossAllPrograms",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_CollaborativeArrangementGlobalDevelopmentOfLicensedProductMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Collaborative Arrangement  Global Development Of Licensed product  [Member]",
        "label": "Collaborative Arrangement Global Development Of Licensed Product [Member]",
        "terseLabel": "Global development of the licensed product"
       }
      }
     },
     "localname": "CollaborativeArrangementGlobalDevelopmentOfLicensedProductMember",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsManufacturingServicesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_CollaborativeArrangementPeriodOfPriorNoticeToTerminateAgreement": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The period of time for which written notice is required to be received from the collaborative partner prior to termination of the collaborative agreement.",
        "label": "Collaborative Arrangement Period Of Prior Notice To Terminate Agreement",
        "terseLabel": "Written termination notice period"
       }
      }
     },
     "localname": "CollaborativeArrangementPeriodOfPriorNoticeToTerminateAgreement",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "bpmc_CommonStockIncreaseCapitalSharesReservedForFutureIssuance": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Increase in aggregate number of common shares reserved for future issuance.",
        "label": "Common Stock Increase Capital Shares Reserved for Future Issuance",
        "terseLabel": "Increase of common shares reserved for future issuance (in shares)"
       }
      }
     },
     "localname": "CommonStockIncreaseCapitalSharesReservedForFutureIssuance",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationEmployeeStockPurchasePlanDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "bpmc_CoronavirusAidReliefAndEconomicSecurityActBonusDepreciationPercentage": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Bonus depreciation percentage under the Coronavirus Aid Relief And Economic Security Act.",
        "label": "Coronavirus Aid Relief And Economic Security Act Bonus Depreciation Percentage",
        "terseLabel": "CARES bonus depreciation percentage"
       }
      }
     },
     "localname": "CoronavirusAidReliefAndEconomicSecurityActBonusDepreciationPercentage",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "bpmc_CoronavirusAidReliefAndEconomicSecurityActCarrybackNetOperatingLossesPeriod": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Duration of operating loss carrybacks under the Coronavirus Aid Relief And Economic Security Act.",
        "label": "Coronavirus Aid Relief And Economic Security Act Carryback Net Operating Losses Period",
        "terseLabel": "CARES net operating losses carryback period"
       }
      }
     },
     "localname": "CoronavirusAidReliefAndEconomicSecurityActCarrybackNetOperatingLossesPeriod",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "bpmc_CoronavirusAidReliefAndEconomicSecurityActCharitableDeductionLimitationPercentage": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Charitable deduction limitation percentage under the Coronavirus Aid Relief And Economic Security Act.",
        "label": "Coronavirus Aid Relief And Economic Security Act Charitable Deduction Limitation Percentage",
        "terseLabel": "CARES charitable deduction limit percentage"
       }
      }
     },
     "localname": "CoronavirusAidReliefAndEconomicSecurityActCharitableDeductionLimitationPercentage",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "bpmc_CoronavirusAidReliefAndEconomicSecurityActQualifiedImprovementPropertyRecoveryPeriod": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Qualified improvement property recovery period under the Coronavirus Aid Relief And Economic Security Act.",
        "label": "Coronavirus Aid Relief And Economic Security Act Qualified Improvement Property Recovery Period",
        "terseLabel": "CARES qualified improvement property recovery period"
       }
      }
     },
     "localname": "CoronavirusAidReliefAndEconomicSecurityActQualifiedImprovementPropertyRecoveryPeriod",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "bpmc_CoronavirusAidReliefAndEconomicSecurityActTaxableIncomeLimitationPercentageEliminated": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Taxable income limitation percentage that was eliminated under the Coronavirus Aid Relief And Economic Security Act.",
        "label": "Coronavirus Aid Relief And Economic Security Act Taxable Income Limitation Percentage Eliminated",
        "terseLabel": "CARES eliminated taxable income limitation percentage"
       }
      }
     },
     "localname": "CoronavirusAidReliefAndEconomicSecurityActTaxableIncomeLimitationPercentageEliminated",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "bpmc_DebtSecuritiesAvailableForSaleNumberOfPositions": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Debt Securities, Available-for-sale, Number of Positions",
        "terseLabel": "Securities with remaining maturities greater than one year"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleNumberOfPositions",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsRemainingMaturitiesDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "bpmc_DevelopmentAndRegulatoryMilestonesMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Development and Regulatory Milestones.",
        "label": "Development And Regulatory Milestones [Member]",
        "terseLabel": "Development and regulatory milestones"
       }
      }
     },
     "localname": "DevelopmentAndRegulatoryMilestonesMember",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_ExerciseOfLicenseOptionProductCommerciallySoldMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents information pertaining to the agreement terms of exercise of license option, where product has been commercially sold under research and development arrangements.",
        "label": "Exercise Of License Option Product Commercially Sold [Member]",
        "terseLabel": "Exercise Of License Option Product Commercially Sold"
       }
      }
     },
     "localname": "ExerciseOfLicenseOptionProductCommerciallySoldMember",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_ExerciseOfLicenseOptionProductNotCommerciallySoldMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents information pertaining to the agreement terms of exercise of license option, where product has not been commercially sold under research and development arrangements.",
        "label": "Exercise Of License Option Product Not Commercially Sold [Member]",
        "terseLabel": "Exercise Of License Option Product Not Commercially Sold"
       }
      }
     },
     "localname": "ExerciseOfLicenseOptionProductNotCommerciallySoldMember",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_ExerciseOfLicenseRightOptionMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents information pertaining to the agreement terms of exercise of license option under research and development arrangements.",
        "label": "Exercise Of License Right Option [Member]",
        "terseLabel": "Exercise Of License Right Option"
       }
      }
     },
     "localname": "ExerciseOfLicenseRightOptionMember",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_ExternalResearchDevelopmentAndCommercialContractCostsCurrent": {
     "auth_ref": [],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_AccruedLiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "External Research, Development and Commercial Contract Costs, Current",
        "label": "External Research, Development and Commercial Contract Costs, Current",
        "terseLabel": "Research, development and commercial contract costs"
       }
      }
     },
     "localname": "ExternalResearchDevelopmentAndCommercialContractCostsCurrent",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_FollowOnOfferingMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Follow-on public offering.",
        "label": "Follow On Offering [Member]",
        "terseLabel": "Follow-on public offering"
       }
      }
     },
     "localname": "FollowOnOfferingMember",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNatureOfBusinessSaleOfStockDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_IncreaseDecreaseInCustomerAssets": {
     "auth_ref": [],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 6.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period of the amount of customer assets.",
        "label": "Increase (Decrease) in Customer Assets",
        "negatedLabel": "Unbilled accounts receivable"
       }
      }
     },
     "localname": "IncreaseDecreaseInCustomerAssets",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_IncreaseDecreaseInOperatingLeaseLiabilities": {
     "auth_ref": [],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 14.0,
       "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 operating lease liabilities incurred.",
        "label": "Increase (Decrease) in Operating Lease Liabilities",
        "terseLabel": "Operating lease liabilities"
       }
      }
     },
     "localname": "IncreaseDecreaseInOperatingLeaseLiabilities",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_InducementPlan2020Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Inducement Plan, 2020 [Member]",
        "label": "Inducement Plan2020 [Member]",
        "terseLabel": "2020 Inducement Plan"
       }
      }
     },
     "localname": "InducementPlan2020Member",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2020InducementPlanDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_InitialCashPaymentPerCollaborationAgreement": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Initial Cash Payment Per Collaboration Agreement.",
        "label": "Initial Cash Payment Per Collaboration Agreement",
        "terseLabel": "Initial cash payment"
       }
      }
     },
     "localname": "InitialCashPaymentPerCollaborationAgreement",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_InterestDeductiblePercentageOfAdjustedTaxableIncome": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The interest deductible percentage of adjusted taxable income.",
        "label": "Interest Deductible Percentage Of Adjusted Taxable Income",
        "terseLabel": "Deductible interest percentage limitation"
       }
      }
     },
     "localname": "InterestDeductiblePercentageOfAdjustedTaxableIncome",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "bpmc_LeaseRightOfUseAssetAmortization": {
     "auth_ref": [],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Lease, Right-of-Use Asset, Amortization.",
        "label": "Lease, Right-of-Use Asset, Amortization",
        "terseLabel": "Noncash lease expense"
       }
      }
     },
     "localname": "LeaseRightOfUseAssetAmortization",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_LicenseMilestoneRevenue": {
     "auth_ref": [],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedCstoneDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "License Milestone Revenue.",
        "label": "License Milestone Revenue",
        "terseLabel": "License milestone revenue"
       }
      }
     },
     "localname": "LicenseMilestoneRevenue",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedCstoneDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_LicensedProductTermFromFirstCommercialSale": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Licensed Product Term From First Commercial Sale.",
        "label": "Licensed Product Term From First Commercial Sale",
        "terseLabel": "Licensed product term from first commercial sale"
       }
      }
     },
     "localname": "LicensedProductTermFromFirstCommercialSale",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "bpmc_ManufacturingServicesRelatedToAgreementActivities": {
     "auth_ref": [],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedCstoneDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Manufacturing Services Related To Agreement Activities.",
        "label": "Manufacturing Services Related To Agreement Activities",
        "terseLabel": "Manufacturing and research and development services related to global development activities",
        "verboseLabel": "Manufacturing services related to territory-specific activities"
       }
      }
     },
     "localname": "ManufacturingServicesRelatedToAgreementActivities",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsManufacturingServicesDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedCstoneDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_MilestoneAxis": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by categories of milestones.",
        "label": "Milestone [Axis]"
       }
      }
     },
     "localname": "MilestoneAxis",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "bpmc_MilestoneDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Different categories of milestones.",
        "label": "Milestone [Domain]",
        "terseLabel": "Milestone [Domain]"
       }
      }
     },
     "localname": "MilestoneDomain",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_NonrefundableUpfrontPaymentReceived": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Non-refundable upfront payment received by the reporting entity from the collaborative partner.",
        "label": "Nonrefundable Upfront Payment Received",
        "terseLabel": "Non-refundable upfront payment received"
       }
      }
     },
     "localname": "NonrefundableUpfrontPaymentReceived",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_NumberOfCollaborationPrograms": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the number of collaboration programs.",
        "label": "Number Of Collaboration Programs",
        "terseLabel": "Number of potential collaboration programs"
       }
      }
     },
     "localname": "NumberOfCollaborationPrograms",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "bpmc_NumberOfCollaborationProgramsWithExclusiveCommercializationRights": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the number of collaboration programs with exclusive commercialization rights for licensed products.",
        "label": "Number Of Collaboration Programs With Exclusive Commercialization Rights",
        "terseLabel": "Number of collaboration programs with exclusive commercialization rights for licensed products"
       }
      }
     },
     "localname": "NumberOfCollaborationProgramsWithExclusiveCommercializationRights",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "bpmc_NumberOfCollaborationProgramsWithSpecifiedCommercializationRights": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the number of collaboration programs in which the entity will retain commercialization rights in the United States for the licensed products, and counterparty will receive commercialization rights outside of the United States for the licensed products.",
        "label": "Number Of Collaboration Programs With Specified Commercialization Rights",
        "terseLabel": "Number of collaboration programs with specified commercial rights for each party"
       }
      }
     },
     "localname": "NumberOfCollaborationProgramsWithSpecifiedCommercializationRights",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "bpmc_NumberOfLicenseOptionRights": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the number of license option rights to obtain an exclusive license to exploit products derived from the collaboration programs.",
        "label": "Number Of License Option Rights",
        "terseLabel": "Number of option rights to obtain exclusive license"
       }
      }
     },
     "localname": "NumberOfLicenseOptionRights",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "bpmc_NumberOfMaterialPromises": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The number of material promises.",
        "label": "Number of Material Promises",
        "terseLabel": "Number of material promises"
       }
      }
     },
     "localname": "NumberOfMaterialPromises",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "bpmc_NumberOfMaterialsComponents": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The number of material components.",
        "label": "Number of Materials Components",
        "terseLabel": "Number of materials components"
       }
      }
     },
     "localname": "NumberOfMaterialsComponents",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "bpmc_NumberOfSmallMoleculeTherapeuticsTargetingKinases": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The number of small molecule therapeutics targeting kinases.",
        "label": "Number Of Small Molecule Therapeutics Targeting Kinases",
        "terseLabel": "Number of small molecule therapeutics targeting kinases"
       }
      }
     },
     "localname": "NumberOfSmallMoleculeTherapeuticsTargetingKinases",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "bpmc_OfficeAndLaboratorySpaceInCambridgeMassachusetts38SidneyStreetAnd45SidneyStreetMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Office and Laboratory Space in Cambridge Massachusetts, 38 Sidney Street, and 45 Sidney Street [Member]",
        "label": "Office And Laboratory Space In Cambridge Massachusetts38 Sidney Street And45 Sidney Street [Member]",
        "terseLabel": "Cambridge Massachusetts, 38 Sidney Street and 45 Sidney Street Leases"
       }
      }
     },
     "localname": "OfficeAndLaboratorySpaceInCambridgeMassachusetts38SidneyStreetAnd45SidneyStreetMember",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_OfficeAndLaboratorySpaceInCambridgeMassachusetts45SidneyStreetExpansionPremisesMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Office and Laboratory Space in Cambridge, Massachusetts, 45 Sidney Street, Expansion Premises [Member]",
        "label": "Office And Laboratory Space In Cambridge Massachusetts45 Sidney Street Expansion Premises [Member]",
        "terseLabel": "Office and Laboratory Space in Cambridge, Massachusetts, 45 Sidney Street, Expansion Premises"
       }
      }
     },
     "localname": "OfficeAndLaboratorySpaceInCambridgeMassachusetts45SidneyStreetExpansionPremisesMember",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_OfficeAndLaboratorySpaceInCambridgeMassachusetts45SidneyStreetMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Office and Laboratory Space in Cambridge, Massachusetts, 45 Sidney Street [Member]",
        "label": "Office And Laboratory Space In Cambridge Massachusetts45 Sidney Street [Member]",
        "terseLabel": "Office and Laboratory Space in Cambridge Massachusetts, 45 Sidney Street"
       }
      }
     },
     "localname": "OfficeAndLaboratorySpaceInCambridgeMassachusetts45SidneyStreetMember",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_OfficeAndLaboratorySpaceInCambridgeMassachusettsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents information pertaining to corporate headquarters office and laboratory space in Cambridge, Massachusetts.",
        "label": "Office And Laboratory Space In Cambridge Massachusetts [Member]",
        "terseLabel": "Corporate Headquarters Lease"
       }
      }
     },
     "localname": "OfficeAndLaboratorySpaceInCambridgeMassachusettsMember",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_OperatingLeasesAllowanceForLeaseholdImprovements": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Allowance granted to lessee and/or direct costs incurred by lessor used to prepare the leased premises for tenant's occupancy.",
        "label": "Operating Leases, Allowance for Leasehold Improvements",
        "terseLabel": "Allowance for leasehold improvements"
       }
      }
     },
     "localname": "OperatingLeasesAllowanceForLeaseholdImprovements",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_OperatingLeasesBaseAnnualRentInitial": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the initial base annual rent for an operating lease.",
        "label": "Operating Leases Base Annual Rent Initial",
        "terseLabel": "Base annual rent, initial"
       }
      }
     },
     "localname": "OperatingLeasesBaseAnnualRentInitial",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_OperatingLeasesBaseAnnualRentMaximum": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the maximum base annual rent for an operating lease.",
        "label": "Operating Leases, Base Annual Rent, Maximum",
        "terseLabel": "Base annual rent, maximum"
       }
      }
     },
     "localname": "OperatingLeasesBaseAnnualRentMaximum",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_OperatingLeasesSubleaseRentalPayableToLandLord": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The Amount of contractually required sublease revenue portion payable to land lord.",
        "label": "Operating Leases, Sublease Rental Payable to Land Lord",
        "terseLabel": "Sublease payable"
       }
      }
     },
     "localname": "OperatingLeasesSubleaseRentalPayableToLandLord",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_PriorToExerciseLicenseRightOptionMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents information pertaining to the agreement terms prior to exercise license right option under research and development arrangements.",
        "label": "Prior To Exercise License Right Option [Member]",
        "terseLabel": "Prior To Exercise License Right Option"
       }
      }
     },
     "localname": "PriorToExerciseLicenseRightOptionMember",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_ProceedsFromIssuanceOfCommonStockNetOfUnderwritingDiscountsCommissionsAndOfferingExpenses": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Proceeds from Issuance of Common Stock, Net of Underwriting Discounts, Commissions, and Offering Expenses",
        "label": "Proceeds from Issuance of Common Stock, Net of Underwriting Discounts, Commissions, and Offering Expenses",
        "terseLabel": "Proceeds from issuance of common stock, net of underwriting discounts and commissions and estimated offering expenses"
       }
      }
     },
     "localname": "ProceedsFromIssuanceOfCommonStockNetOfUnderwritingDiscountsCommissionsAndOfferingExpenses",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNatureOfBusinessSaleOfStockDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_ReclassificationsPolicyPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for reclassification.",
        "label": "Reclassifications Policy Policy [Text Block]",
        "terseLabel": "Reclassification"
       }
      }
     },
     "localname": "ReclassificationsPolicyPolicyTextBlock",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "bpmc_RocheMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Roche [Member]",
        "label": "Roche [Member]",
        "terseLabel": "Roche"
       }
      }
     },
     "localname": "RocheMember",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedRocheDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_SalesBasedMilestonesMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Sales Based Milestones.",
        "label": "Sales Based Milestones [Member]",
        "terseLabel": "Sales-based milestones"
       }
      }
     },
     "localname": "SalesBasedMilestonesMember",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_ScheduleOfManufacturingServicesRelatedToAgreementActivitiesTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of manufacturing services related to the global development activities.",
        "label": "Schedule Of Manufacturing Services Related To Agreement Activities [Table Text Block]",
        "terseLabel": "Summary of manufacturing and research and development services related to the global development activities"
       }
      }
     },
     "localname": "ScheduleOfManufacturingServicesRelatedToAgreementActivitiesTableTextBlock",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "bpmc_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfAdditionalSharesAuthorized": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The percentage of additional shares authorized for issuance under an established share-based compensation plan.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Additional Shares Authorized",
        "terseLabel": "Increase in number of shares available for grant (as a percent)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfAdditionalSharesAuthorized",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2015StockOptionAndIncentivePlanDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "bpmc_SignificantAccountingPolicyPolicyTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of significant accounting policies.",
        "label": "Significant Accounting Policy [Policy Text Block]",
        "terseLabel": "Significant Accounting Policies"
       }
      }
     },
     "localname": "SignificantAccountingPolicyPolicyTextBlock",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "bpmc_StockIssuanceCostsIncurredButNotYetPaidNoncashOrPartialNoncashTransaction": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the future cash outflow to pay stock issuance costs that have occurred in a noncash or partial noncash transaction.",
        "label": "Stock Issuance Costs Incurred but Not yet Paid Noncash Or Partial Noncash Transaction",
        "terseLabel": "Public offering costs incurred but unpaid at period end"
       }
      }
     },
     "localname": "StockIssuanceCostsIncurredButNotYetPaidNoncashOrPartialNoncashTransaction",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "bpmc_StockOptionAndIncentivePlan2015Member": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the stock option and incentive plan approved in 2015.",
        "label": "Stock Option And Incentive Plan2015 [Member]",
        "terseLabel": "2015 Stock Option and Incentive Plan"
       }
      }
     },
     "localname": "StockOptionAndIncentivePlan2015Member",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2015StockOptionAndIncentivePlanDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "bpmc_TaxCutsAndJobsAct2017InterestDeductiblePercentageOfAdjustedTaxableIncome": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The interest deductible percentage of adjusted taxable income under the Tax Cuts And Jobs Act 2017.",
        "label": "Tax Cuts And Jobs Act 2017 Interest Deductible Percentage Of Adjusted Taxable Income",
        "terseLabel": "Tax Cuts and Jobs Act of 2017 deductible interest percentage limitation"
       }
      }
     },
     "localname": "TaxCutsAndJobsAct2017InterestDeductiblePercentageOfAdjustedTaxableIncome",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "bpmc_UnbilledReceivablesIncludingReimbursableCostsCurrent": {
     "auth_ref": [],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Represents the current amount of unbilled accounts receivable, including reimbursable research and development costs.",
        "label": "Unbilled Receivables Including Reimbursable Costs Current",
        "terseLabel": "Unbilled accounts receivable"
       }
      }
     },
     "localname": "UnbilledReceivablesIncludingReimbursableCostsCurrent",
     "nsuri": "http://www.blueprintmedicines.com/20200506",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsContractAssetsCstoneDetails",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_CityAreaCode": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Area code of city",
        "label": "City Area Code"
       }
      }
     },
     "localname": "CityAreaCode",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_CoverAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Cover page.",
        "label": "Cover [Abstract]"
       }
      }
     },
     "localname": "CoverAbstract",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "dei_CurrentFiscalYearEndDate": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "End date of current fiscal year in the format --MM-DD.",
        "label": "Current Fiscal Year End Date"
       }
      }
     },
     "localname": "CurrentFiscalYearEndDate",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "gMonthDayItemType"
    },
    "dei_DocumentFiscalPeriodFocus": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Fiscal period values are FY, Q1, Q2, and Q3.  1st, 2nd and 3rd quarter 10-Q or 10-QT statements have value Q1, Q2, and Q3 respectively, with 10-K, 10-KT or other fiscal year statements having FY.",
        "label": "Document Fiscal Period Focus"
       }
      }
     },
     "localname": "DocumentFiscalPeriodFocus",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "fiscalPeriodItemType"
    },
    "dei_DocumentFiscalYearFocus": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This is focus fiscal year of the document report in CCYY format. For a 2006 annual report, which may also provide financial information from prior periods, fiscal 2006 should be given as the fiscal year focus. Example: 2006.",
        "label": "Document Fiscal Year Focus"
       }
      }
     },
     "localname": "DocumentFiscalYearFocus",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "gYearItemType"
    },
    "dei_DocumentPeriodEndDate": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented.  If there is no historical data in the report, use the filing date. The format of the date is CCYY-MM-DD.",
        "label": "Document Period End Date"
       }
      }
     },
     "localname": "DocumentPeriodEndDate",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "dateItemType"
    },
    "dei_DocumentQuarterlyReport": {
     "auth_ref": [
      "r284"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_DocumentTransitionReport": {
     "auth_ref": [
      "r285"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_DocumentType": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.",
        "label": "Document Type"
       }
      }
     },
     "localname": "DocumentType",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "submissionTypeItemType"
    },
    "dei_EntityAddressAddressLine1": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Address Line 1 such as Attn, Building Name, Street Name",
        "label": "Entity Address, Address Line One"
       }
      }
     },
     "localname": "EntityAddressAddressLine1",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressCityOrTown": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Name of the City or Town",
        "label": "Entity Address, City or Town"
       }
      }
     },
     "localname": "EntityAddressCityOrTown",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressPostalZipCode": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Code for the postal or zip code",
        "label": "Entity Address, Postal Zip Code"
       }
      }
     },
     "localname": "EntityAddressPostalZipCode",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityAddressStateOrProvince": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Name of the state or province.",
        "label": "Entity Address, State or Province"
       }
      }
     },
     "localname": "EntityAddressStateOrProvince",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "stateOrProvinceItemType"
    },
    "dei_EntityCentralIndexKey": {
     "auth_ref": [
      "r286"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "centralIndexKeyItemType"
    },
    "dei_EntityCommonStockSharesOutstanding": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Indicate number of shares or other units outstanding of each of registrant's classes of capital or common stock or other ownership interests, if and as stated on cover of related periodic report. Where multiple classes or units exist define each class/interest by adding class of stock items such as Common Class A [Member], Common Class B [Member] or Partnership Interest [Member] onto the Instrument [Domain] of the Entity Listings, Instrument.",
        "label": "Entity Common Stock, Shares Outstanding"
       }
      }
     },
     "localname": "EntityCommonStockSharesOutstanding",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "sharesItemType"
    },
    "dei_EntityCurrentReportingStatus": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Indicate 'Yes' or 'No' whether registrants (1) have filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that registrants were required to file such reports), and (2) have been subject to such filing requirements for the past 90 days. This information should be based on the registrant's current or most recent filing containing the related disclosure.",
        "label": "Entity Current Reporting Status"
       }
      }
     },
     "localname": "EntityCurrentReportingStatus",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityEmergingGrowthCompany": {
     "auth_ref": [
      "r286"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntityFileNumber": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.",
        "label": "Entity File Number"
       }
      }
     },
     "localname": "EntityFileNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "fileNumberItemType"
    },
    "dei_EntityFilerCategory": {
     "auth_ref": [
      "r286"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "filerCategoryItemType"
    },
    "dei_EntityIncorporationStateCountryCode": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Two-character EDGAR code representing the state or country of incorporation.",
        "label": "Entity Incorporation, State or Country Code"
       }
      }
     },
     "localname": "EntityIncorporationStateCountryCode",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "edgarStateCountryItemType"
    },
    "dei_EntityInteractiveDataCurrent": {
     "auth_ref": [
      "r287"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "yesNoItemType"
    },
    "dei_EntityListingParValuePerShare": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The par value per share of security quoted in same currency as Trading currency. Example: '0.01'.",
        "label": "Entity Listing, Par Value Per Share"
       }
      }
     },
     "localname": "EntityListingParValuePerShare",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "perShareItemType"
    },
    "dei_EntityRegistrantName": {
     "auth_ref": [
      "r286"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_EntityShellCompany": {
     "auth_ref": [
      "r286"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntitySmallBusiness": {
     "auth_ref": [
      "r286"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "booleanItemType"
    },
    "dei_EntityTaxIdentificationNumber": {
     "auth_ref": [
      "r286"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "employerIdItemType"
    },
    "dei_LocalPhoneNumber": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Local phone number for entity.",
        "label": "Local Phone Number"
       }
      }
     },
     "localname": "LocalPhoneNumber",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "normalizedStringItemType"
    },
    "dei_Security12bTitle": {
     "auth_ref": [
      "r282"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "securityTitleItemType"
    },
    "dei_SecurityExchangeName": {
     "auth_ref": [
      "r283"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "edgarExchangeCodeItemType"
    },
    "dei_TradingSymbol": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Trading symbol of an instrument as listed on an exchange.",
        "label": "Trading Symbol"
       }
      }
     },
     "localname": "TradingSymbol",
     "nsuri": "http://xbrl.sec.gov/dei/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DocumentDocumentAndEntityInformation"
     ],
     "xbrltype": "tradingSymbolItemType"
    },
    "srt_CounterpartyNameAxis": {
     "auth_ref": [
      "r47",
      "r91"
     ],
     "lang": {
      "en-US": {
       "role": {
        "label": "Counterparty Name [Axis]"
       }
      }
     },
     "localname": "CounterpartyNameAxis",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsContractAssetsCstoneDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsManufacturingServicesDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedCstoneDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedRocheDetails",
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_MaximumMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Maximum [Member]",
        "terseLabel": "Maximum"
       }
      }
     },
     "localname": "MaximumMember",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_ProductOrServiceAxis": {
     "auth_ref": [
      "r114",
      "r168",
      "r171",
      "r274",
      "r275"
     ],
     "lang": {
      "en-US": {
       "role": {
        "label": "Product and Service [Axis]"
       }
      }
     },
     "localname": "ProductOrServiceAxis",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueDetails",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_ProductsAndServicesDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Products And Services [Domain]",
        "terseLabel": "Product and Service [Domain]"
       }
      }
     },
     "localname": "ProductsAndServicesDomain",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueDetails",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RangeAxis": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Range [Axis]"
       }
      }
     },
     "localname": "RangeAxis",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "srt_RangeMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Range [Member]",
        "terseLabel": "Range [Domain]"
       }
      }
     },
     "localname": "RangeMember",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "srt_RepurchaseAgreementCounterpartyNameDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Repurchase Agreement Counterparty Name [Domain]",
        "terseLabel": "Counterparty Name [Domain]"
       }
      }
     },
     "localname": "RepurchaseAgreementCounterpartyNameDomain",
     "nsuri": "http://fasb.org/srt/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsContractAssetsCstoneDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsManufacturingServicesDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedCstoneDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedRocheDetails",
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccountingPoliciesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Accounting Policies [Abstract]"
       }
      }
     },
     "localname": "AccountingPoliciesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccountingStandardsUpdate201613Member": {
     "auth_ref": [
      "r130"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Accounting Standards Update 2016-13 Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.",
        "label": "Accounting Standards Update201613 [Member]",
        "terseLabel": "Accounting Standards Update 2016-13"
       }
      }
     },
     "localname": "AccountingStandardsUpdate201613Member",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNewAccountingPronouncementsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccountingStandardsUpdate201813Member": {
     "auth_ref": [
      "r235"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Accounting Standards Update 2018-13 Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement.",
        "label": "Accounting Standards Update201813 [Member]",
        "terseLabel": "Accounting Standards Update 2018-13"
       }
      }
     },
     "localname": "AccountingStandardsUpdate201813Member",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNewAccountingPronouncementsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccountingStandardsUpdate201815Member": {
     "auth_ref": [
      "r147",
      "r148"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Accounting Standards Update 2018-15 Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (a consensus of the FASB Emerging Issues Task Force).",
        "label": "Accounting Standards Update201815 [Member]",
        "terseLabel": "Accounting Standards Update 2018-15"
       }
      }
     },
     "localname": "AccountingStandardsUpdate201815Member",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNewAccountingPronouncementsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccountingStandardsUpdate201818Member": {
     "auth_ref": [
      "r214",
      "r215"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Accounting Standards Update 2018-18 Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606.",
        "label": "Accounting Standards Update201818 [Member]",
        "terseLabel": "Accounting Standards Update 2018-18"
       }
      }
     },
     "localname": "AccountingStandardsUpdate201818Member",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNewAccountingPronouncementsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock": {
     "auth_ref": [
      "r35"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for accounts payable and accrued liabilities at the end of the reporting period.",
        "label": "Accounts Payable and Accrued Liabilities Disclosure [Text Block]",
        "terseLabel": "Accrued Expenses"
       }
      }
     },
     "localname": "AccountsPayableAndAccruedLiabilitiesDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpenses"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_AccountsPayableCurrent": {
     "auth_ref": [
      "r34"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
        "label": "Accounts Payable, Current",
        "terseLabel": "Accounts payable"
       }
      }
     },
     "localname": "AccountsPayableCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccountsReceivableMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Due from customers or clients for goods or services that have been delivered or sold.",
        "label": "Accounts Receivable [Member]",
        "terseLabel": "Accounts Receivable"
       }
      }
     },
     "localname": "AccountsReceivableMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueAllowanceLocationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccountsReceivableNetCurrent": {
     "auth_ref": [
      "r2",
      "r16",
      "r115",
      "r116",
      "r169"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 6.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.",
        "label": "Accounts Receivable, Net, Current",
        "terseLabel": "Accounts receivable"
       }
      }
     },
     "localname": "AccountsReceivableNetCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsContractAssetsCstoneDetails",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccruedLiabilitiesCurrent": {
     "auth_ref": [
      "r37"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
        "label": "Accrued expenses",
        "terseLabel": "Accrued expenses",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "AccruedLiabilitiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesDetails",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccruedLiabilitiesCurrentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Accrued Liabilities, Current [Abstract]",
        "terseLabel": "Accrued Expenses"
       }
      }
     },
     "localname": "AccruedLiabilitiesCurrentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AccruedLiabilitiesMember": {
     "auth_ref": [
      "r37"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This item represents 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.",
        "label": "Accrued Liabilities [Member]",
        "terseLabel": "Accrued Expenses"
       }
      }
     },
     "localname": "AccruedLiabilitiesMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueAllowanceLocationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AccruedProfessionalFeesCurrent": {
     "auth_ref": [
      "r6",
      "r7",
      "r37"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesDetails": {
       "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 fees"
       }
      }
     },
     "localname": "AccruedProfessionalFeesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment": {
     "auth_ref": [
      "r32",
      "r152"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails": {
       "order": 1.0,
       "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax": {
     "auth_ref": [
      "r52",
      "r53",
      "r54"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 3.0,
       "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AccumulatedOtherComprehensiveIncomeMember": {
     "auth_ref": [
      "r51",
      "r54",
      "r55",
      "r220"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Accumulated increase (decrease) in equity from transactions and other events and circumstances from non-owner sources, attributable to the parent. Excludes net income (loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners.",
        "label": "Accumulated Other Comprehensive Income [Member]",
        "terseLabel": "Accumulated Other Comprehensive Loss"
       }
      }
     },
     "localname": "AccumulatedOtherComprehensiveIncomeMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AdditionalPaidInCapital": {
     "auth_ref": [
      "r17"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 2.0,
       "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AdditionalPaidInCapitalMember": {
     "auth_ref": [],
     "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"
       }
      }
     },
     "localname": "AdditionalPaidInCapitalMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AdjustmentsForNewAccountingPronouncementsAxis": {
     "auth_ref": [
      "r94"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by new accounting pronouncement.",
        "label": "Adjustments for New Accounting Pronouncements [Axis]"
       }
      }
     },
     "localname": "AdjustmentsForNewAccountingPronouncementsAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNewAccountingPronouncementsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]",
        "terseLabel": "Adjustments to reconcile net loss to net cash used in operating activities:"
       }
      }
     },
     "localname": "AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue": {
     "auth_ref": [
      "r176",
      "r178",
      "r204",
      "r205"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase to additional paid-in capital (APIC) for recognition of cost for award under share-based payment arrangement.",
        "label": "Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition",
        "terseLabel": "Stock-based compensation expense"
       }
      }
     },
     "localname": "AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AllocatedShareBasedCompensationExpense": {
     "auth_ref": [
      "r178",
      "r199",
      "r203"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardCompensationCost1",
       "weight": 1.0
      }
     },
     "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"
       }
      }
     },
     "localname": "AllocatedShareBasedCompensationExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AllowanceForCreditLossesTextBlock": {
     "auth_ref": [
      "r119"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for allowance for credit losses.",
        "label": "Allowance for Credit Losses [Text Block]",
        "terseLabel": "Product Revenue Reserves and Allowances"
       }
      }
     },
     "localname": "AllowanceForCreditLossesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowances"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount": {
     "auth_ref": [
      "r98"
     ],
     "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 computation of earnings per share"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNetLossPerShareDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis": {
     "auth_ref": [
      "r98"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by type of antidilutive security.",
        "label": "Antidilutive Securities [Axis]"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNetLossPerShareDetails"
     ],
     "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]"
       }
      }
     },
     "localname": "AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNetLossPerShareDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AntidilutiveSecuritiesNameDomain": {
     "auth_ref": [
      "r98"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNetLossPerShareDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_AreaOfRealEstateProperty": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Area of a real estate property.",
        "label": "Area of Real Estate Property",
        "terseLabel": "Area leased (in square feet)"
       }
      }
     },
     "localname": "AreaOfRealEstateProperty",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "areaItemType"
    },
    "us-gaap_ArrangementsAndNonarrangementTransactionsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Collaborative arrangement and arrangement other than collaborative applicable to revenue-generating activity or operations.",
        "label": "Arrangements And Nonarrangement Transactions [Member]",
        "terseLabel": "Arrangements and Non-arrangement Transactions [Domain]"
       }
      }
     },
     "localname": "ArrangementsAndNonarrangementTransactionsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsContractAssetsCstoneDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsManufacturingServicesDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedCstoneDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedRocheDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_Assets": {
     "auth_ref": [
      "r112",
      "r259",
      "r266"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "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": "Total assets",
        "totalLabel": "Total assets"
       }
      }
     },
     "localname": "Assets",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AssetsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Assets [Abstract]"
       }
      }
     },
     "localname": "AssetsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AssetsCurrent": {
     "auth_ref": [
      "r3",
      "r4",
      "r46"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.",
        "label": "Assets, Current",
        "totalLabel": "Total current assets"
       }
      }
     },
     "localname": "AssetsCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AssetsFairValueDisclosure": {
     "auth_ref": [
      "r226"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.",
        "label": "Assets, Fair Value Disclosure",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "AssetsFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax": {
     "auth_ref": [
      "r125"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureInvestmentsAvailableForSaleDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax",
        "verboseLabel": "Available-for-sale, Unrealized Gain"
       }
      }
     },
     "localname": "AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureInvestmentsAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax": {
     "auth_ref": [
      "r126"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureInvestmentsAvailableForSaleDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax",
        "negatedLabel": "Available-for-sale, Unrealized Losses"
       }
      }
     },
     "localname": "AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureInvestmentsAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis": {
     "auth_ref": [
      "r123",
      "r137"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureInvestmentsAvailableForSaleDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Available-for-sale Debt Securities, Amortized Cost Basis",
        "totalLabel": "Available-for-sale, Amortized Cost"
       }
      }
     },
     "localname": "AvailableForSaleDebtSecuritiesAmortizedCostBasis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureInvestmentsAvailableForSaleDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]",
        "verboseLabel": "Unrealized loss position, aggregate fair value"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLossAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsUnrealizedLossPositionDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueRollingMaturityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract]",
        "terseLabel": "Investments, available-for-sale"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesFairValueRollingMaturityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsRemainingMaturitiesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue": {
     "auth_ref": [],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Fair value of investment in debt security, measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year through fifth year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.",
        "label": "Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Fair Value",
        "terseLabel": "Aggregate fair value with remaining maturities greater than one year"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsRemainingMaturitiesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtSecurities": {
     "auth_ref": [
      "r120",
      "r124",
      "r137"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureInvestmentsAvailableForSaleDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis",
       "weight": 1.0
      },
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_AssetsFairValueDisclosure",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Available-for-sale Securities, Debt Securities",
        "verboseLabel": "Investments, available-for-sale"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtSecurities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureInvestmentsAvailableForSaleDetails",
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent": {
     "auth_ref": [
      "r122",
      "r137"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as current.",
        "label": "Available-for-sale Securities, Debt Securities, Current",
        "terseLabel": "Investments, available-for-sale"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtSecuritiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent": {
     "auth_ref": [
      "r122",
      "r137"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as noncurrent.",
        "label": "Available-for-sale Securities, Debt Securities, Noncurrent",
        "terseLabel": "Investments, available-for-sale"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesDebtSecuritiesNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]",
        "terseLabel": "Investments, available-for-sale:"
       }
      }
     },
     "localname": "AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureInvestmentsAvailableForSaleDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AvailableForsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions [Abstract]",
        "terseLabel": "Unrealized loss position, number of positions"
       }
      }
     },
     "localname": "AvailableForsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsUnrealizedLossPositionDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_AwardTypeAxis": {
     "auth_ref": [
      "r180",
      "r202"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by type of award under share-based payment arrangement.",
        "label": "Award Type [Axis]"
       }
      }
     },
     "localname": "AwardTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationEmployeeStockPurchasePlanDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationUnrecognizedCompensationCostsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_BalanceSheetLocationAxis": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by location on balance sheet (statement of financial position).",
        "label": "Balance Sheet Location [Axis]"
       }
      }
     },
     "localname": "BalanceSheetLocationAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueAllowanceLocationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_BalanceSheetLocationDomain": {
     "auth_ref": [
      "r224",
      "r225"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Location in the balance sheet (statement of financial position).",
        "label": "Balance Sheet Location [Domain]",
        "terseLabel": "Balance Sheet Location [Domain]"
       }
      }
     },
     "localname": "BalanceSheetLocationDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueAllowanceLocationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "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 Presentation"
       }
      }
     },
     "localname": "BasisOfAccountingPolicyPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_CapitalExpendituresIncurredButNotYetPaid": {
     "auth_ref": [
      "r85",
      "r86",
      "r87"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Future cash outflow to pay for purchases of fixed assets that have occurred.",
        "label": "Capital Expenditures Incurred but Not yet Paid",
        "terseLabel": "Property and equipment purchases unpaid at period end"
       }
      }
     },
     "localname": "CapitalExpendituresIncurredButNotYetPaid",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashAndCashEquivalentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Cash and Cash Equivalents [Abstract]",
        "terseLabel": "Cash equivalents:"
       }
      }
     },
     "localname": "CashAndCashEquivalentsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureCashEquivalentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CashAndCashEquivalentsAtCarryingValue": {
     "auth_ref": [
      "r0",
      "r30",
      "r83"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      },
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlowsParenthetical": {
       "order": 1.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents",
       "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlowsParenthetical"
     ],
     "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]"
       }
      }
     },
     "localname": "CashAndCashEquivalentsAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureCashEquivalentsDetails",
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CashAndCashEquivalentsFairValueDisclosure": {
     "auth_ref": [],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureCashEquivalentsDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_CashEquivalentsAtCarryingValue",
       "weight": 1.0
      },
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_AssetsFairValueDisclosure",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.",
        "label": "Cash and Cash Equivalents, Fair Value Disclosure",
        "terseLabel": "Cash equivalents"
       }
      }
     },
     "localname": "CashAndCashEquivalentsFairValueDisclosure",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureCashEquivalentsDetails",
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashAndCashEquivalentsLineItems": {
     "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": "Cash and Cash Equivalents [Line Items]"
       }
      }
     },
     "localname": "CashAndCashEquivalentsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureCashEquivalentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CashCashEquivalentsAndMarketableSecuritiesTextBlock": {
     "auth_ref": [
      "r10",
      "r129"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure of cash, cash equivalents, and debt and equity securities, including any unrealized or realized gain (loss).",
        "label": "Cash, Cash Equivalents, and Marketable Securities [Text Block]",
        "terseLabel": "Cash Equivalents and Investments"
       }
      }
     },
     "localname": "CashCashEquivalentsAndMarketableSecuritiesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestments"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_CashCashEquivalentsAndShortTermInvestments": {
     "auth_ref": [
      "r30"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Cash includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the customer may deposit additional funds at any time and effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid Investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Short-term investments, exclusive of cash equivalents, generally consist of marketable securities intended to be sold within one year (or the normal operating cycle if longer) and may include trading securities, available-for-sale securities, or held-to-maturity securities (if maturing within one year), as applicable.",
        "label": "Cash, Cash Equivalents, and Short-term Investments",
        "verboseLabel": "Cash, cash equivalents and investments"
       }
      }
     },
     "localname": "CashCashEquivalentsAndShortTermInvestments",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNatureOfBusinessCashCashEquivalentsAndInvestmentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashCashEquivalentsAndShortTermInvestmentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Cash, Cash Equivalents, and Short-term Investments [Abstract]",
        "terseLabel": "Cash, cash equivalents and investments"
       }
      }
     },
     "localname": "CashCashEquivalentsAndShortTermInvestmentsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNatureOfBusinessCashCashEquivalentsAndInvestmentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents": {
     "auth_ref": [
      "r78",
      "r83",
      "r88"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlowsParenthetical": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage. Excludes amount for disposal group and discontinued operations. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.",
        "label": "Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents",
        "periodEndLabel": "Cash, cash equivalents and restricted cash at end of period",
        "periodStartLabel": "Cash, cash equivalents and restricted cash at beginning of period",
        "totalLabel": "Total cash, cash equivalents, and restricted cash shown in condensed consolidated statements of cash flows"
       }
      }
     },
     "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlowsParenthetical"
     ],
     "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"
       }
      }
     },
     "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlowsParenthetical"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect": {
     "auth_ref": [
      "r78",
      "r236"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "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 increase in cash, cash equivalents, and restricted cash"
       }
      }
     },
     "localname": "CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashEquivalentsAtCarryingValue": {
     "auth_ref": [
      "r30"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureCashEquivalentsDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "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",
        "totalLabel": "Cash equivalents, Amortized Cost"
       }
      }
     },
     "localname": "CashEquivalentsAtCarryingValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureCashEquivalentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CashEquivalentsMember": {
     "auth_ref": [
      "r10"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "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 Equivalents [Member]",
        "terseLabel": "Cash Equivalents [Member]"
       }
      }
     },
     "localname": "CashEquivalentsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureCashEquivalentsDetails",
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CashFlowOperatingActivitiesLesseeAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Cash Flow, Operating Activities, Lessee [Abstract]",
        "terseLabel": "Leases"
       }
      }
     },
     "localname": "CashFlowOperatingActivitiesLesseeAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesCashFlowInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ChangeInAccountingPrincipleAccountingStandardsUpdateAdopted": {
     "auth_ref": [
      "r94"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Indicates (true false) whether accounting standards update was adopted.",
        "label": "Change in Accounting Principle, Accounting Standards Update, Adopted [true false]",
        "verboseLabel": "Change in Accounting Principle, Accounting Standards Update, Adopted"
       }
      }
     },
     "localname": "ChangeInAccountingPrincipleAccountingStandardsUpdateAdopted",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNewAccountingPronouncementsDetails"
     ],
     "xbrltype": "booleanItemType"
    },
    "us-gaap_ChangeInAccountingPrincipleAccountingStandardsUpdateAdoptionDate": {
     "auth_ref": [
      "r95"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Date accounting standards update was adopted, in CCYY-MM-DD format.",
        "label": "Change in Accounting Principle, Accounting Standards Update, Adoption Date",
        "verboseLabel": "Change in Accounting Principle, Accounting Standards Update, Adoption Date"
       }
      }
     },
     "localname": "ChangeInAccountingPrincipleAccountingStandardsUpdateAdoptionDate",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNewAccountingPronouncementsDetails"
     ],
     "xbrltype": "dateItemType"
    },
    "us-gaap_ChangeInAccountingPrincipleAccountingStandardsUpdateEarlyAdoption": {
     "auth_ref": [
      "r94"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Indicates (true false) whether accounting standards update was early adopted.",
        "label": "Change in Accounting Principle, Accounting Standards Update, Early Adoption [true false]",
        "verboseLabel": "Change in Accounting Principle, Accounting Standards Update, Early Adoption"
       }
      }
     },
     "localname": "ChangeInAccountingPrincipleAccountingStandardsUpdateEarlyAdoption",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNewAccountingPronouncementsDetails"
     ],
     "xbrltype": "booleanItemType"
    },
    "us-gaap_CollaborativeArrangementDisclosureTextBlock": {
     "auth_ref": [
      "r211",
      "r212",
      "r216"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for collaborative arrangements in which the entity is a participant, including a) information about the nature and purpose of such arrangements; b) its rights and obligations thereunder; c) the accounting policy for collaborative arrangements; and d) the income statement classification and amounts attributable to transactions arising from the collaborative arrangement between participants.",
        "label": "Collaborative Arrangement Disclosure [Text Block]",
        "terseLabel": "Collaboration and License Agreements"
       }
      }
     },
     "localname": "CollaborativeArrangementDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreements"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_CollaborativeArrangementMember": {
     "auth_ref": [
      "r213"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Contractual arrangement that involves two or more parties that both: (i) actively participate in a joint operating activity and (ii) are exposed to significant risks and rewards that depend on the commercial success of the joint operating activity.",
        "label": "Collaborative Arrangement [Member]",
        "terseLabel": "Collaboration"
       }
      }
     },
     "localname": "CollaborativeArrangementMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsContractAssetsCstoneDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedCstoneDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedRocheDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems": {
     "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": "Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]",
        "terseLabel": "Collaboration Agreements",
        "verboseLabel": "Collaboration Agreements"
       }
      }
     },
     "localname": "CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsContractAssetsCstoneDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsManufacturingServicesDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedCstoneDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedRocheDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CommitmentsAndContingencies": {
     "auth_ref": [
      "r40",
      "r157",
      "r262",
      "r271"
     ],
     "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 (Note 15)"
       }
      }
     },
     "localname": "CommitmentsAndContingencies",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "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/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_CommitmentsDisclosureTextBlock": {
     "auth_ref": [
      "r156"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for significant arrangements with third parties, which includes operating lease arrangements and arrangements in which the entity has agreed to expend funds to procure goods or services, or has agreed to commit resources to supply goods or services, and operating lease arrangements. Descriptions may include identification of the specific goods and services, period of time covered, minimum quantities and amounts, and cancellation rights.",
        "label": "Commitments Disclosure [Text Block]",
        "terseLabel": "Commitments"
       }
      }
     },
     "localname": "CommitmentsDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCommitments"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_CommonStockCapitalSharesReservedForFutureIssuance": {
     "auth_ref": [
      "r41"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Aggregate number of common shares reserved for future issuance.",
        "label": "Common Stock, Capital Shares Reserved for Future Issuance",
        "terseLabel": "Number of common shares reserved for future issuance (in shares)"
       }
      }
     },
     "localname": "CommonStockCapitalSharesReservedForFutureIssuance",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationEmployeeStockPurchasePlanDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Stock that is subordinate to all other stock of the issuer.",
        "label": "Common Stock [Member]",
        "terseLabel": "Common Stock"
       }
      }
     },
     "localname": "CommonStockMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_CommonStockNumberOfSharesParValueAndOtherDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]",
        "terseLabel": "Common Stock Disclosures"
       }
      }
     },
     "localname": "CommonStockNumberOfSharesParValueAndOtherDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_CommonStockParOrStatedValuePerShare": {
     "auth_ref": [
      "r15"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Face amount or stated value per share of common stock.",
        "label": "Common Stock, Par or Stated Value Per Share",
        "terseLabel": "Common stock, par value (in dollars per share)"
       }
      }
     },
     "localname": "CommonStockParOrStatedValuePerShare",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_CommonStockSharesAuthorized": {
     "auth_ref": [
      "r15"
     ],
     "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 (in shares)"
       }
      }
     },
     "localname": "CommonStockSharesAuthorized",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockSharesIssued": {
     "auth_ref": [
      "r15"
     ],
     "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",
        "periodEndLabel": "Ending Balance (in shares)",
        "periodStartLabel": "Beginning Balance (in shares)",
        "terseLabel": "Common stock, shares issued (in shares)"
       }
      }
     },
     "localname": "CommonStockSharesIssued",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockSharesOutstanding": {
     "auth_ref": [
      "r15",
      "r158"
     ],
     "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 (in shares)"
       }
      }
     },
     "localname": "CommonStockSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_CommonStockValue": {
     "auth_ref": [
      "r15"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 4.0,
       "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",
        "verboseLabel": "Common stock, $0.001 par value; 120,000,000 shares authorized; 54,168,533 and 49,272,223 shares issued and outstanding at March 31, 2020 and December 31, 2019, respectively"
       }
      }
     },
     "localname": "CommonStockValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ComprehensiveIncomeNetOfTax": {
     "auth_ref": [
      "r57",
      "r59",
      "r60"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "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"
       }
      }
     },
     "localname": "ComputerEquipmentMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetEstimatedUsefulLivesDetails",
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "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"
       }
      }
     },
     "localname": "ConstructionInProgressMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss": {
     "auth_ref": [
      "r131",
      "r132",
      "r135",
      "r162"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of accumulated credit loss for right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.",
        "label": "Contract with Customer, Asset, Allowance for Credit Loss",
        "periodEndLabel": "Ending balance",
        "periodStartLabel": "Beginning balance",
        "verboseLabel": "Product revenue allowance"
       }
      }
     },
     "localname": "ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueAllowanceLocationDetails",
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueAllowanceRollForwardDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRecovery": {
     "auth_ref": [
      "r134"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase in allowance for credit loss on right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, from recovery.",
        "label": "Contract with Customer, Asset, Allowance for Credit Loss, Recovery",
        "negatedLabel": "Credits and payments made"
       }
      }
     },
     "localname": "ContractWithCustomerAssetAllowanceForCreditLossRecovery",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueAllowanceRollForwardDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward": {
     "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": "Contract with Customer, Asset, Allowance for Credit Loss [Roll Forward]",
        "terseLabel": "Product revenue allowance"
       }
      }
     },
     "localname": "ContractWithCustomerAssetAllowanceForCreditLossRollForward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueAllowanceRollForwardDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ContractWithCustomerAssetAllowanceForCreditLossTableTextBlock": {
     "auth_ref": [
      "r136"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of allowance for credit loss on right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.",
        "label": "Contract with Customer, Asset, Allowance for Credit Loss [Table Text Block]",
        "terseLabel": "Schedule of product revenue allowance and reserve categories"
       }
      }
     },
     "localname": "ContractWithCustomerAssetAllowanceForCreditLossTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock": {
     "auth_ref": [
      "r164"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of contract balances and changes in contract balances.",
        "label": "Contract with Customer, Asset and Liability [Table Text Block]",
        "terseLabel": "Summary of receivables"
       }
      }
     },
     "localname": "ContractWithCustomerAssetAndLiabilityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ContractWithCustomerAssetCreditLossExpense": {
     "auth_ref": [
      "r133",
      "r163",
      "r167"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of expense (reversal of expense) for expected credit loss on right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.",
        "label": "Contract with Customer, Asset, Credit Loss Expense (Reversal)",
        "terseLabel": "Provision related to sales in the current period"
       }
      }
     },
     "localname": "ContractWithCustomerAssetCreditLossExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueAllowanceRollForwardDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerAssetNetAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Contract with Customer, Asset, after Allowance for Credit Loss [Abstract]",
        "terseLabel": "Product revenue allowance"
       }
      }
     },
     "localname": "ContractWithCustomerAssetNetAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueAllowanceLocationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ContractWithCustomerLiability": {
     "auth_ref": [
      "r160",
      "r161",
      "r169"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.",
        "label": "Contract with Customer, Liability",
        "terseLabel": "Deferred revenue"
       }
      }
     },
     "localname": "ContractWithCustomerLiability",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerLiabilityCurrent": {
     "auth_ref": [
      "r160",
      "r161",
      "r169"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_LiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current.",
        "label": "Contract with Customer, Liability, Current",
        "terseLabel": "Current portion of deferred revenue"
       }
      }
     },
     "localname": "ContractWithCustomerLiabilityCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerLiabilityNoncurrent": {
     "auth_ref": [
      "r160",
      "r161",
      "r169"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 3.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as noncurrent.",
        "label": "Contract with Customer, Liability, Noncurrent",
        "terseLabel": "Deferred revenue, net of current portion"
       }
      }
     },
     "localname": "ContractWithCustomerLiabilityNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ContractWithCustomerLiabilityRevenueRecognized": {
     "auth_ref": [
      "r170"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.",
        "label": "Contract with Customer, Liability, Revenue Recognized",
        "terseLabel": "Revenue recognized, change in contract liability",
        "verboseLabel": "Amounts included in the contact liability at the beginning of the period"
       }
      }
     },
     "localname": "ContractWithCustomerLiabilityRevenueRecognized",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedRocheDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CostOfGoodsAndServicesSold": {
     "auth_ref": [
      "r64"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 1.0,
       "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",
        "terseLabel": "Cost of sales"
       }
      }
     },
     "localname": "CostOfGoodsAndServicesSold",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_CostsAndExpenses": {
     "auth_ref": [
      "r63"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 2.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "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 cost and operating expenses"
       }
      }
     },
     "localname": "CostsAndExpenses",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss": {
     "auth_ref": [
      "r127",
      "r138"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.",
        "label": "Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss",
        "terseLabel": "Unrealized loss position"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsUnrealizedLossPositionDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions": {
     "auth_ref": [
      "r128",
      "r139"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.",
        "label": "Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions",
        "terseLabel": "Number of held securities in an unrealized loss position"
       }
      }
     },
     "localname": "DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsUnrealizedLossPositionDetails"
     ],
     "xbrltype": "integerItemType"
    },
    "us-gaap_Depreciation": {
     "auth_ref": [
      "r81",
      "r150"
     ],
     "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 expense"
       }
      }
     },
     "localname": "Depreciation",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetDepreciationExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DepreciationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Depreciation [Abstract]",
        "terseLabel": "Depreciation expense"
       }
      }
     },
     "localname": "DepreciationAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetDepreciationExpenseDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DepreciationDepletionAndAmortization": {
     "auth_ref": [
      "r81",
      "r111"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.",
        "label": "Depreciation, Depletion and Amortization",
        "terseLabel": "Depreciation and amortization"
       }
      }
     },
     "localname": "DepreciationDepletionAndAmortization",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_DisaggregationOfRevenueLineItems": {
     "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": "Disaggregation of Revenue [Line Items]"
       }
      }
     },
     "localname": "DisaggregationOfRevenueLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueAllowanceLocationDetails",
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DisaggregationOfRevenueTable": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about disaggregation of revenue into categories depicting how nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factor.",
        "label": "Disaggregation of Revenue [Table]"
       }
      }
     },
     "localname": "DisaggregationOfRevenueTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueAllowanceLocationDetails",
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_DisaggregationOfRevenueTableTextBlock": {
     "auth_ref": [
      "r168"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of disaggregation of revenue into categories depicting how nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factor.",
        "label": "Disaggregation of Revenue [Table Text Block]",
        "terseLabel": "Summary of revenue recognized"
       }
      }
     },
     "localname": "DisaggregationOfRevenueTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock": {
     "auth_ref": [
      "r206"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for share-based payment arrangement.",
        "label": "Disclosure of Compensation Related Costs, Share-based Payments [Text Block]",
        "terseLabel": "Stock-based Compensation"
       }
      }
     },
     "localname": "DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation"
     ],
     "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/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_DisclosureTextBlockAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Disclosure Text Block [Abstract]",
        "terseLabel": "Disclosure Text Block"
       }
      }
     },
     "localname": "DisclosureTextBlockAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpenses",
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestments",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreements",
      "http://www.blueprintmedicines.com/role/DisclosureCommitments",
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstruments",
      "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxes",
      "http://www.blueprintmedicines.com/role/DisclosureInventory",
      "http://www.blueprintmedicines.com/role/DisclosureLeases",
      "http://www.blueprintmedicines.com/role/DisclosureNatureOfBusiness",
      "http://www.blueprintmedicines.com/role/DisclosureNetLossPerShare",
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowances",
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNet",
      "http://www.blueprintmedicines.com/role/DisclosureRestrictedCash",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation",
      "http://www.blueprintmedicines.com/role/DisclosureSubsequentEvents",
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncements"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_EarningsPerShareAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Earnings Per Share [Abstract]"
       }
      }
     },
     "localname": "EarningsPerShareAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_EarningsPerShareBasicAndDiluted": {
     "auth_ref": [
      "r97"
     ],
     "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": "Net loss per share - basic and diluted"
       }
      }
     },
     "localname": "EarningsPerShareBasicAndDiluted",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_EarningsPerShareBasicAndDilutedOtherDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract]",
        "terseLabel": "Antidilutive securities excluded from computation of earnings per share"
       }
      }
     },
     "localname": "EarningsPerShareBasicAndDilutedOtherDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNetLossPerShareDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_EarningsPerShareTextBlock": {
     "auth_ref": [
      "r100"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNetLossPerShare"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents": {
     "auth_ref": [
      "r236"
     ],
     "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, cash equivalents and restricted cash"
       }
      }
     },
     "localname": "EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Effective Income Tax Rate Reconciliation, Percent [Abstract]",
        "verboseLabel": "Income Taxes"
       }
      }
     },
     "localname": "EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_EmployeeRelatedLiabilitiesCurrent": {
     "auth_ref": [
      "r37"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesDetails": {
       "order": 3.0,
       "parentTag": "us-gaap_AccruedLiabilitiesCurrent",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).",
        "label": "Employee-related Liabilities, Current",
        "terseLabel": "Employee compensation"
       }
      }
     },
     "localname": "EmployeeRelatedLiabilitiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Employee Service Share-based Compensation, Aggregate Disclosures [Abstract]",
        "terseLabel": "Total stock based compensation expense"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationAggregateDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount": {
     "auth_ref": [
      "r200"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardCompensationCost1",
       "weight": 1.0
      }
     },
     "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",
        "negatedLabel": "Capitalized stock-based compensation costs"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails"
     ],
     "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]"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized": {
     "auth_ref": [
      "r201"
     ],
     "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": "Total unrecognized compensation cost related to non-vested stock awards"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationUnrecognizedCompensationCostsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Abstract]",
        "terseLabel": "Stock-based compensation"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationUnrecognizedCompensationCostsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1": {
     "auth_ref": [
      "r201"
     ],
     "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 period over which unrecognized compensation cost will be recognized"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationUnrecognizedCompensationCostsDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions": {
     "auth_ref": [
      "r201"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cost to be recognized for option under share-based payment arrangement.",
        "label": "Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options",
        "terseLabel": "Total unrecognized compensation cost related to non-vested stock option awards"
       }
      }
     },
     "localname": "EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationUnrecognizedCompensationCostsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_EmployeeStockMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "An Employee Stock Purchase Plan is a tax-efficient means by which employees of a corporation can purchase the corporation's stock.",
        "label": "Employee Stock [Member]",
        "terseLabel": "Employee Stock"
       }
      }
     },
     "localname": "EmployeeStockMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNetLossPerShareDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationEmployeeStockPurchasePlanDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_EmployeeStockOptionMember": {
     "auth_ref": [
      "r197"
     ],
     "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"
       }
      }
     },
     "localname": "EmployeeStockOptionMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNetLossPerShareDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails"
     ],
     "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": "Lab equipment"
       }
      }
     },
     "localname": "EquipmentMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetEstimatedUsefulLivesDetails",
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_EquityComponentDomain": {
     "auth_ref": [
      "r158"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Components of equity are the parts of the total Equity balance including that which is allocated to common, preferred, treasury stock, retained earnings, etc.",
        "label": "Equity Component [Domain]",
        "terseLabel": "Equity Component [Domain]"
       }
      }
     },
     "localname": "EquityComponentDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "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]"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable": {
     "auth_ref": [
      "r226",
      "r227",
      "r228",
      "r233"
     ],
     "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]"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTableTextBlock": {
     "auth_ref": [
      "r226",
      "r227",
      "r228",
      "r232",
      "r233"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of financial instruments measured at fair value, including those classified in shareholders' equity measured on a recurring or nonrecurring basis. Disclosures include, but are not limited to, fair value measurements recorded and the reasons for the measurements, level within the fair value hierarchy in which the fair value measurements are categorized and transfers between levels 1 and 2. Nonrecurring fair value measurements are those that are required or permitted in the statement of financial position in particular circumstances.",
        "label": "Fair Value Measurements, Recurring and Nonrecurring [Table Text Block]",
        "terseLabel": "Schedule of financial instruments measured at fair value"
       }
      }
     },
     "localname": "FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueByFairValueHierarchyLevelAxis": {
     "auth_ref": [
      "r173",
      "r174",
      "r175",
      "r227",
      "r255"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by level within fair value hierarchy and fair value measured at net asset value per share as practical expedient.",
        "label": "Fair Value, Hierarchy [Axis]"
       }
      }
     },
     "localname": "FairValueByFairValueHierarchyLevelAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueByMeasurementFrequencyAxis": {
     "auth_ref": [
      "r226",
      "r227",
      "r229",
      "r230",
      "r234"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by measurement frequency.",
        "label": "Measurement Frequency [Axis]"
       }
      }
     },
     "localname": "FairValueByMeasurementFrequencyAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Fair Value Disclosures [Abstract]"
       }
      }
     },
     "localname": "FairValueDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_FairValueDisclosuresTextBlock": {
     "auth_ref": [
      "r231"
     ],
     "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 of Financial Instruments"
       }
      }
     },
     "localname": "FairValueDisclosuresTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstruments"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_FairValueInputsLevel12And3Member": {
     "auth_ref": [
      "r174"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Fair value measurement input including quoted price in active market for identical asset or liability reporting entity can access at measurement date (level 1), input other than quoted price included within level 1 either directly or indirectly observable for asset or liability (level 2) and unobservable input reflecting entity's own assumption (level 3).",
        "label": "Fair Value Inputs Level12 And3 [Member]",
        "terseLabel": "Fair Value, Inputs, Level 1, 2 and 3 [Member]"
       }
      }
     },
     "localname": "FairValueInputsLevel12And3Member",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueInputsLevel1Member": {
     "auth_ref": [
      "r173",
      "r174",
      "r175",
      "r227",
      "r256"
     ],
     "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 Level1 [Member]",
        "terseLabel": "Active Markets (Level 1)"
       }
      }
     },
     "localname": "FairValueInputsLevel1Member",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueInputsLevel2Member": {
     "auth_ref": [
      "r173",
      "r174",
      "r175",
      "r227",
      "r257"
     ],
     "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 Level2 [Member]",
        "terseLabel": "Observable Inputs (Level 2)"
       }
      }
     },
     "localname": "FairValueInputsLevel2Member",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueMeasurementsFairValueHierarchyDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Categories used to prioritize the inputs to valuation techniques to measure fair value.",
        "label": "Fair Value Measurements Fair Value Hierarchy [Domain]",
        "terseLabel": "Fair Value Hierarchy [Domain]"
       }
      }
     },
     "localname": "FairValueMeasurementsFairValueHierarchyDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueMeasurementsRecurringMember": {
     "auth_ref": [
      "r231",
      "r234"
     ],
     "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": "Recurring"
       }
      }
     },
     "localname": "FairValueMeasurementsRecurringMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_FairValueNetAssetLiabilityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Fair Value, Net Asset (Liability) [Abstract]",
        "terseLabel": "Fair Value of Financial Instruments"
       }
      }
     },
     "localname": "FairValueNetAssetLiabilityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_FurnitureAndFixturesMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Equipment commonly used in offices and stores that have no permanent connection to the structure of a building or utilities. Examples include, but are not limited to, desks, chairs, tables, and bookcases.",
        "label": "Furniture And Fixtures [Member]",
        "terseLabel": "Furniture and fixtures"
       }
      }
     },
     "localname": "FurnitureAndFixturesMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetEstimatedUsefulLivesDetails",
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_GeneralAndAdministrativeExpenseMember": {
     "auth_ref": [
      "r62"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Primary financial statement caption encompassing general and administrative expense.",
        "label": "General And Administrative Expense [Member]",
        "terseLabel": "General and administrative"
       }
      }
     },
     "localname": "GeneralAndAdministrativeExpenseMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_IncomeStatementAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Income Statement [Abstract]"
       }
      }
     },
     "localname": "IncomeStatementAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeStatementLocationAxis": {
     "auth_ref": [
      "r154"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by location in the income statement.",
        "label": "Income Statement Location [Axis]"
       }
      }
     },
     "localname": "IncomeStatementLocationAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeStatementLocationDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Location in the income statement.",
        "label": "Income Statement Location [Domain]",
        "terseLabel": "Income Statement Location [Domain]"
       }
      }
     },
     "localname": "IncomeStatementLocationDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_IncomeTaxDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Income Tax Disclosure [Abstract]"
       }
      }
     },
     "localname": "IncomeTaxDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncomeTaxDisclosureTextBlock": {
     "auth_ref": [
      "r210"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.",
        "label": "Income Tax Disclosure [Text Block]",
        "terseLabel": "Income Taxes"
       }
      }
     },
     "localname": "IncomeTaxDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxes"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_IncomeTaxesPaidNet": {
     "auth_ref": [
      "r84"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes.",
        "label": "Income Taxes Paid, Net",
        "terseLabel": "Cash paid for taxes, net"
       }
      }
     },
     "localname": "IncomeTaxesPaidNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInAccountsPayable": {
     "auth_ref": [
      "r80"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 5.0,
       "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 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.",
        "label": "Increase (Decrease) in Accounts Payable",
        "terseLabel": "Accounts payable"
       }
      }
     },
     "localname": "IncreaseDecreaseInAccountsPayable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInAccountsReceivable": {
     "auth_ref": [
      "r80"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 10.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The increase (decrease) during the reporting period in amount due within one year (or one business cycle) from customers for the credit sale of goods and services.",
        "label": "Increase (Decrease) in Accounts Receivable",
        "negatedLabel": "Accounts receivable"
       }
      }
     },
     "localname": "IncreaseDecreaseInAccountsReceivable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInAccruedLiabilities": {
     "auth_ref": [
      "r80"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 12.0,
       "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 expenses incurred but not yet paid.",
        "label": "Increase (Decrease) in Accrued Liabilities",
        "terseLabel": "Accrued expenses"
       }
      }
     },
     "localname": "IncreaseDecreaseInAccruedLiabilities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInContractWithCustomerLiability": {
     "auth_ref": [
      "r80"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 13.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase (decrease) in obligation to transfer good or service to customer for which consideration has been received or is receivable.",
        "label": "Increase (Decrease) in Contract with Customer, Liability",
        "terseLabel": "Deferred revenue"
       }
      }
     },
     "localname": "IncreaseDecreaseInContractWithCustomerLiability",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInInventories": {
     "auth_ref": [
      "r80"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 7.0,
       "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": "Inventory"
       }
      }
     },
     "localname": "IncreaseDecreaseInInventories",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInOperatingCapitalAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Increase (Decrease) in Operating Capital [Abstract]",
        "terseLabel": "Changes in assets and liabilities:"
       }
      }
     },
     "localname": "IncreaseDecreaseInOperatingCapitalAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_IncreaseDecreaseInOtherNoncurrentAssets": {
     "auth_ref": [
      "r80"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 11.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of increase (decrease) in noncurrent assets classified as other.",
        "label": "Increase (Decrease) in Other Noncurrent Assets",
        "negatedLabel": "Other assets"
       }
      }
     },
     "localname": "IncreaseDecreaseInOtherNoncurrentAssets",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets": {
     "auth_ref": [
      "r80"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 8.0,
       "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 current assets"
       }
      }
     },
     "localname": "IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_IncreaseDecreaseInStockholdersEquityRollForward": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Increase (Decrease) in Stockholders' Equity [Roll Forward]",
        "terseLabel": "Increase (Decrease) in Stockholders' Equity"
       }
      }
     },
     "localname": "IncreaseDecreaseInStockholdersEquityRollForward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_InterestIncomeExpenseNet": {
     "auth_ref": [
      "r265"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 2.0,
       "parentTag": "us-gaap_NonoperatingIncomeExpense",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The net amount of operating interest income (expense).",
        "label": "Interest Income (Expense), Net",
        "terseLabel": "Interest income (expense), net"
       }
      }
     },
     "localname": "InterestIncomeExpenseNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InventoryDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Inventory Disclosure [Abstract]"
       }
      }
     },
     "localname": "InventoryDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_InventoryDisclosureTextBlock": {
     "auth_ref": [
      "r146"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for inventory. Includes, but is not limited to, the basis of stating inventory, the method of determining inventory cost, the classes of inventory, and the nature of the cost elements included in inventory.",
        "label": "Inventory Disclosure [Text Block]",
        "terseLabel": "Inventory"
       }
      }
     },
     "localname": "InventoryDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureInventory"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_InventoryFinishedGoodsNetOfReserves": {
     "auth_ref": [
      "r23",
      "r145"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureInventoryCapitalizedDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_InventoryNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of merchandise or goods held by the company that are readily available for sale.",
        "label": "Inventory, Finished Goods, Net of Reserves",
        "terseLabel": "Finished goods"
       }
      }
     },
     "localname": "InventoryFinishedGoodsNetOfReserves",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureInventoryCapitalizedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InventoryNet": {
     "auth_ref": [
      "r1",
      "r43",
      "r141"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureInventoryCapitalizedDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_AssetsCurrent",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.",
        "label": "Inventory, Net",
        "terseLabel": "Inventory",
        "totalLabel": "Total"
       }
      }
     },
     "localname": "InventoryNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureInventoryCapitalizedDetails",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InventoryNetAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Inventory, Net [Abstract]",
        "terseLabel": "Inventory"
       }
      }
     },
     "localname": "InventoryNetAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureInventoryCapitalizedDetails",
      "http://www.blueprintmedicines.com/role/DisclosureInventoryWriteDownDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_InventoryPolicyTextBlock": {
     "auth_ref": [
      "r9",
      "r44",
      "r89",
      "r101",
      "r142",
      "r144"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of inventory accounting policy for inventory classes, including, but not limited to, basis for determining inventory amounts, methods by which amounts are added and removed from inventory classes, loss recognition on impairment of inventories, and situations in which inventories are stated above cost.",
        "label": "Inventory, Policy [Policy Text Block]",
        "terseLabel": "Inventory"
       }
      }
     },
     "localname": "InventoryPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_InventoryWorkInProcessNetOfReserves": {
     "auth_ref": [
      "r24",
      "r145"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureInventoryCapitalizedDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_InventoryNet",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Carrying amount, net of reserves and adjustments, as of the balance sheet date of merchandise or goods which are partially completed. This inventory is generally comprised of raw materials, labor and factory overhead costs, which require further materials, labor and overhead to be converted into finished goods, and which generally require the use of estimates to determine percentage complete and pricing.",
        "label": "Inventory, Work in Process, Net of Reserves",
        "terseLabel": "Work in process"
       }
      }
     },
     "localname": "InventoryWorkInProcessNetOfReserves",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureInventoryCapitalizedDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InventoryWriteDown": {
     "auth_ref": [
      "r143"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of loss from reductions in inventory due to subsequent measurement adjustments, including, but not limited to, physical deterioration, obsolescence, or changes in price levels.",
        "label": "Inventory Write-down",
        "terseLabel": "Inventory write-down"
       }
      }
     },
     "localname": "InventoryWriteDown",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureInventoryWriteDownDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_InvestmentTypeAxis": {
     "auth_ref": [
      "r276",
      "r277",
      "r278",
      "r279"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by type of investments.",
        "label": "Investment Type [Axis]"
       }
      }
     },
     "localname": "InvestmentTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureInvestmentsAvailableForSaleDetails",
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_InvestmentTypeCategorizationMember": {
     "auth_ref": [
      "r276",
      "r277",
      "r278",
      "r279"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Asset obtained to generate income or appreciate in value.",
        "label": "Investment Type Categorization [Member]",
        "terseLabel": "Investments [Domain]"
       }
      }
     },
     "localname": "InvestmentTypeCategorizationMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureInvestmentsAvailableForSaleDetails",
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_InvestmentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Investments [Abstract]",
        "terseLabel": "Cash Equivalents and Investments"
       }
      }
     },
     "localname": "InvestmentsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureTotalDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_InvestmentsAndCashAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Investments and Cash [Abstract]"
       }
      }
     },
     "localname": "InvestmentsAndCashAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_LeaseCost": {
     "auth_ref": [
      "r250",
      "r252"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureLeasesComponentsOfLeaseExpenseDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of lease cost recognized by lessee for lease contract.",
        "label": "Lease, Cost",
        "totalLabel": "Net lease cost"
       }
      }
     },
     "localname": "LeaseCost",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesComponentsOfLeaseExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LeaseCostAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Operating leases cost:"
       }
      }
     },
     "localname": "LeaseCostAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesComponentsOfLeaseExpenseDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LeaseCostTableTextBlock": {
     "auth_ref": [
      "r250"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of lessee's lease cost. Includes, but is not limited to, interest expense for finance lease, amortization of right-of-use asset for finance lease, operating lease cost, short-term lease cost, variable lease cost and sublease income.",
        "label": "Lease, Cost [Table Text Block]",
        "terseLabel": "Summary of lease expenses and cash flow and weighted average information"
       }
      }
     },
     "localname": "LeaseCostTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_LeaseholdImprovementsMember": {
     "auth_ref": [
      "r151"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Additions or improvements to assets held under a lease arrangement.",
        "label": "Leasehold Improvements [Member]",
        "terseLabel": "Leasehold improvements"
       }
      }
     },
     "localname": "LeaseholdImprovementsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetEstimatedUsefulLivesDetails",
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_LeasesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Leases [Abstract]"
       }
      }
     },
     "localname": "LeasesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_LesseeDisclosureAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Lessee Disclosure [Abstract]",
        "terseLabel": "Leases"
       }
      }
     },
     "localname": "LesseeDisclosureAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesWeightedAverageRemainingLeaseTermAndWeightedAverageDiscountRateDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LesseeLeaseDescriptionLineItems": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Lessee, Lease, Description [Line Items]"
       }
      }
     },
     "localname": "LesseeLeaseDescriptionLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LesseeLeaseDescriptionTable": {
     "auth_ref": [
      "r243"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about lessee's leases.",
        "label": "Lessee, Lease, Description [Table]"
       }
      }
     },
     "localname": "LesseeLeaseDescriptionTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LesseeOperatingLeaseDescriptionAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Lessee, Operating Lease, Description [Abstract]",
        "terseLabel": "Leases"
       }
      }
     },
     "localname": "LesseeOperatingLeaseDescriptionAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LesseeOperatingLeaseExistenceOfOptionToExtend": {
     "auth_ref": [
      "r242"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Indicates (true false) whether lessee has option to extend operating lease.",
        "label": "Lessee, Operating Lease, Existence of Option to Extend [true false]",
        "terseLabel": "Lessee, Operating Lease, Existence of Option to Extend"
       }
      }
     },
     "localname": "LesseeOperatingLeaseExistenceOfOptionToExtend",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "booleanItemType"
    },
    "us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue": {
     "auth_ref": [
      "r251"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of lessee's undiscounted obligation for lease payments for operating lease.",
        "label": "Lessee, Operating Lease, Liability, Payments, Due",
        "terseLabel": "Initial lease commitments"
       }
      }
     },
     "localname": "LesseeOperatingLeaseLiabilityPaymentsDue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LesseeOperatingLeaseRenewalTerm": {
     "auth_ref": [
      "r242"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.",
        "label": "Lessee, Operating Lease, Renewal Term",
        "terseLabel": "Extension period of lease term"
       }
      }
     },
     "localname": "LesseeOperatingLeaseRenewalTerm",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_LesseeOperatingLeaseTermOfContract": {
     "auth_ref": [
      "r242"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.",
        "label": "Lessee, Operating Lease, Term of Contract",
        "verboseLabel": "Initial lease term"
       }
      }
     },
     "localname": "LesseeOperatingLeaseTermOfContract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_LesseeOperatingLeasesTextBlock": {
     "auth_ref": [
      "r253"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for operating leases of lessee. Includes, but is not limited to, description of operating lease and maturity analysis of operating lease liability.",
        "label": "Lessee, Operating Leases [Text Block]",
        "terseLabel": "Leases"
       }
      }
     },
     "localname": "LesseeOperatingLeasesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeases"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_Liabilities": {
     "auth_ref": [
      "r36"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 2.0,
       "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": "Total liabilities",
        "totalLabel": "Total liabilities"
       }
      }
     },
     "localname": "Liabilities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_LiabilitiesAndStockholdersEquity": {
     "auth_ref": [
      "r21",
      "r260",
      "r269"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LiabilitiesCurrent": {
     "auth_ref": [
      "r38"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 1.0,
       "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": "Total current liabilities",
        "totalLabel": "Total current liabilities"
       }
      }
     },
     "localname": "LiabilitiesCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_LicenseAgreementTermsMember": {
     "auth_ref": [
      "r208",
      "r209"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Terms of the license agreements under research and development arrangements accounted for as a contract to perform research and development for others.",
        "label": "License Agreement Terms [Member]",
        "terseLabel": "License Agreement Terms [Member]"
       }
      }
     },
     "localname": "LicenseAgreementTermsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_MoneyMarketFundsMember": {
     "auth_ref": [
      "r173"
     ],
     "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"
       }
      }
     },
     "localname": "MoneyMarketFundsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureCashEquivalentsDetails",
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_NatureOfOperations": {
     "auth_ref": [
      "r102",
      "r110"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for the nature of an entity's business, major products or services, principal markets including location, and the relative importance of its operations in each business and the basis for the determination, including but not limited to, assets, revenues, or earnings. For an entity that has not commenced principal operations, disclosures about the risks and uncertainties related to the activities in which the entity is currently engaged and an understanding of what those activities are being directed toward.",
        "label": "Nature of Operations [Text Block]",
        "terseLabel": "Nature of Business"
       }
      }
     },
     "localname": "NatureOfOperations",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNatureOfBusiness"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_NetCashProvidedByUsedInFinancingActivities": {
     "auth_ref": [
      "r78"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Net Cash Provided by (Used in) Financing Activities [Abstract]",
        "verboseLabel": "Cash flows from financing activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInFinancingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetCashProvidedByUsedInInvestingActivities": {
     "auth_ref": [
      "r78"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Net Cash Provided by (Used in) Investing Activities [Abstract]",
        "verboseLabel": "Cash flows from investing activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInInvestingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetCashProvidedByUsedInOperatingActivities": {
     "auth_ref": [
      "r78",
      "r79",
      "r82"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Net Cash Provided by (Used in) Operating Activities [Abstract]",
        "verboseLabel": "Cash flows from operating activities"
       }
      }
     },
     "localname": "NetCashProvidedByUsedInOperatingActivitiesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NetIncomeLoss": {
     "auth_ref": [
      "r56",
      "r58",
      "r61",
      "r82",
      "r99",
      "r264",
      "r272"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NewAccountingPronouncementMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Sources of change to generally accepted accounting principles (GAAP) in the United States. The FASB released the FASB Accounting Standards Codification as the authoritative source of literature effective for interim and annual periods ending after September 15, 2009. As part of the Codification process, the FASB issues \"Accounting Standards Updates\" to amend the Codification but otherwise the Accounting Standards Updates are not authoritative in their own right. All previous accounting standards (such as FASB Statements of Financial Accounting Standards, FASB Interpretations, FASB Staff Positions, Emerging Issues Task Force Consensuses, other pronouncements of the FASB or other designated bodies, or other forms of GAAP are considered accounting pronouncements) were superseded upon the adoption of the Codification. For an interim period, references to the superseded standards are included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.",
        "label": "New Accounting Pronouncement [Member]",
        "terseLabel": "Adjustments for New Accounting Pronouncement [Member]"
       }
      }
     },
     "localname": "NewAccountingPronouncementMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNewAccountingPronouncementsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems": {
     "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": "New Accounting Pronouncements or Change in Accounting Principle [Line Items]",
        "verboseLabel": "Summary of Significant Accounting Policies and Recent Accounting Pronouncements"
       }
      }
     },
     "localname": "NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNewAccountingPronouncementsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable": {
     "auth_ref": [
      "r94",
      "r95"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Summarization of the changes in an accounting principle or a new accounting pronouncement, including the line items affected by the change and the financial effects of the change on those particular line items.",
        "label": "New Accounting Pronouncements or Change in Accounting Principle [Table]"
       }
      }
     },
     "localname": "NewAccountingPronouncementsOrChangeInAccountingPrincipleTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNewAccountingPronouncementsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "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": "New Accounting Pronouncements"
       }
      }
     },
     "localname": "NewAccountingPronouncementsPolicyPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_NonoperatingIncomeExpense": {
     "auth_ref": [
      "r67"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 3.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).",
        "label": "Nonoperating Income (Expense)",
        "totalLabel": "Total other income"
       }
      }
     },
     "localname": "NonoperatingIncomeExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_NonoperatingIncomeExpenseAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Nonoperating Income (Expense) [Abstract]",
        "terseLabel": "Other income (expense):"
       }
      }
     },
     "localname": "NonoperatingIncomeExpenseAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OperatingExpensesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Operating Expenses [Abstract]",
        "terseLabel": "Cost and operating expenses"
       }
      }
     },
     "localname": "OperatingExpensesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OperatingLeaseCost": {
     "auth_ref": [
      "r244",
      "r252"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureLeasesComponentsOfLeaseExpenseDetails": {
       "order": 1.0,
       "parentTag": "us-gaap_LeaseCost",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.",
        "label": "Operating Lease, Cost",
        "terseLabel": "Lease cost"
       }
      }
     },
     "localname": "OperatingLeaseCost",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesComponentsOfLeaseExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseLiabilityCurrent": {
     "auth_ref": [
      "r240"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 3.0,
       "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": "Current portion of operating lease liabilities",
        "terseLabel": "Current portion of operating lease liabilities"
       }
      }
     },
     "localname": "OperatingLeaseLiabilityCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseLiabilityNoncurrent": {
     "auth_ref": [
      "r240"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 2.0,
       "parentTag": "us-gaap_Liabilities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent.",
        "label": "Operating lease liabilities, net of current portion",
        "terseLabel": "Operating lease liabilities, net of current portion"
       }
      }
     },
     "localname": "OperatingLeaseLiabilityNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeasePayments": {
     "auth_ref": [
      "r241",
      "r246"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.",
        "label": "Operating lease liabilities",
        "terseLabel": "Cash paid for amounts included in the measurement of lease liabilities, operating cash flows from operating leases"
       }
      }
     },
     "localname": "OperatingLeasePayments",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesCashFlowInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseRightOfUseAsset": {
     "auth_ref": [
      "r239"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 4.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of lessee's right to use underlying asset under operating lease.",
        "label": "Operating lease right-of-use assets, net",
        "terseLabel": "Operating lease right-of-use assets, net"
       }
      }
     },
     "localname": "OperatingLeaseRightOfUseAsset",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent": {
     "auth_ref": [
      "r249",
      "r252"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Weighted average discount rate for operating lease calculated at point in time.",
        "label": "Operating Lease, Weighted Average Discount Rate, Percent",
        "terseLabel": "Weighted average discount rate"
       }
      }
     },
     "localname": "OperatingLeaseWeightedAverageDiscountRatePercent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesWeightedAverageRemainingLeaseTermAndWeightedAverageDiscountRateDetails"
     ],
     "xbrltype": "percentItemType"
    },
    "us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1": {
     "auth_ref": [
      "r248",
      "r252"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.",
        "label": "Operating Lease, Weighted Average Remaining Lease Term",
        "terseLabel": "Weighted average remaining lease term in years"
       }
      }
     },
     "localname": "OperatingLeaseWeightedAverageRemainingLeaseTerm1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesWeightedAverageRemainingLeaseTermAndWeightedAverageDiscountRateDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_OperatingLeasesFutureMinimumPaymentsDueFutureMinimumSubleaseRentals": {
     "auth_ref": [
      "r238"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Contractually required future rental payments receivable on noncancelable subleasing arrangements.",
        "label": "Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals",
        "terseLabel": "Total commitment in sublease"
       }
      }
     },
     "localname": "OperatingLeasesFutureMinimumPaymentsDueFutureMinimumSubleaseRentals",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "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/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_OrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock": {
     "auth_ref": [
      "r93",
      "r96",
      "r110",
      "r223"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for the general note to the financial statements for the reporting entity which may include, descriptions of the basis of presentation, business description, significant accounting policies, consolidations, reclassifications, new pronouncements not yet adopted and changes in accounting principles.",
        "label": "Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]",
        "terseLabel": "Summary of Significant Accounting Policies and Recent Accounting Pronouncements"
       }
      }
     },
     "localname": "OrganizationConsolidationBasisOfPresentationBusinessDescriptionAndAccountingPoliciesTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncements"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_OtherAccruedLiabilitiesCurrent": {
     "auth_ref": [
      "r6",
      "r7",
      "r8",
      "r37"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesDetails": {
       "order": 6.0,
       "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherAssetsNoncurrent": {
     "auth_ref": [
      "r33"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 5.0,
       "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"
       }
      }
     },
     "localname": "OtherAssetsNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax": {
     "auth_ref": [
      "r49",
      "r50",
      "r52"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount before tax, after reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.",
        "label": "Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Tax",
        "terseLabel": "Unrealized gain (loss) on available-for-sale securities"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax": {
     "auth_ref": [
      "r48",
      "r237"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 2.0,
       "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": "Currency translation adjustments",
        "verboseLabel": "Cumulative translation adjustment"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]",
        "terseLabel": "Other comprehensive loss:"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax": {
     "auth_ref": [
      "r49",
      "r52"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 3.0,
       "parentTag": "us-gaap_ComprehensiveIncomeNetOfTax",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount after tax, before reclassification adjustments, of unrealized holding gain (loss) on available-for-sale securities.",
        "label": "Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax",
        "verboseLabel": "Unrealized gain (losses) on available-for-sale investments"
       }
      }
     },
     "localname": "OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherLiabilitiesNoncurrent": {
     "auth_ref": [
      "r39"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 4.0,
       "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 long-term liabilities"
       }
      }
     },
     "localname": "OtherLiabilitiesNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_OtherNonoperatingIncomeExpense": {
     "auth_ref": [
      "r69"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 1.0,
       "parentTag": "us-gaap_NonoperatingIncomeExpense",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of income (expense) related to nonoperating activities, classified as other.",
        "label": "Other Nonoperating Income (Expense)",
        "terseLabel": "Other income (expense), net"
       }
      }
     },
     "localname": "OtherNonoperatingIncomeExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PayablesAndAccrualsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Payables and Accruals [Abstract]"
       }
      }
     },
     "localname": "PayablesAndAccrualsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt": {
     "auth_ref": [
      "r70",
      "r72",
      "r121"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cash outflow to acquire investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Payments to Acquire Available-for-sale Securities, Debt",
        "negatedLabel": "Purchases of investments"
       }
      }
     },
     "localname": "PaymentsToAcquireAvailableForSaleSecuritiesDebt",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PaymentsToAcquirePropertyPlantAndEquipment": {
     "auth_ref": [
      "r73"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.",
        "label": "Payments to Acquire Property, Plant, and Equipment",
        "negatedLabel": "Purchases of property and equipment"
       }
      }
     },
     "localname": "PaymentsToAcquirePropertyPlantAndEquipment",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PlanNameAxis": {
     "auth_ref": [
      "r180",
      "r202"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by plan name for share-based payment arrangement.",
        "label": "Plan Name [Axis]"
       }
      }
     },
     "localname": "PlanNameAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2015StockOptionAndIncentivePlanDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2020InducementPlanDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PlanNameDomain": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Plan name for share-based payment arrangement.",
        "label": "Plan Name [Domain]",
        "terseLabel": "Plan Name [Domain]"
       }
      }
     },
     "localname": "PlanNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2015StockOptionAndIncentivePlanDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2020InducementPlanDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PolicyTextBlockAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Policy Text Block [Abstract]",
        "terseLabel": "Policy Text Blocks"
       }
      }
     },
     "localname": "PolicyTextBlockAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsPolicies"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PreferredStockNumberOfSharesParValueAndOtherDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]",
        "terseLabel": "Preferred Stock Disclosures"
       }
      }
     },
     "localname": "PreferredStockNumberOfSharesParValueAndOtherDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PreferredStockParOrStatedValuePerShare": {
     "auth_ref": [
      "r14"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.",
        "label": "Preferred Stock, Par or Stated Value Per Share",
        "terseLabel": "Preferred stock, par value (in dollars per share)"
       }
      }
     },
     "localname": "PreferredStockParOrStatedValuePerShare",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_PreferredStockSharesAuthorized": {
     "auth_ref": [
      "r14"
     ],
     "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 (in shares)"
       }
      }
     },
     "localname": "PreferredStockSharesAuthorized",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_PreferredStockSharesIssued": {
     "auth_ref": [
      "r14"
     ],
     "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 (in shares)"
       }
      }
     },
     "localname": "PreferredStockSharesIssued",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_PreferredStockSharesOutstanding": {
     "auth_ref": [
      "r14"
     ],
     "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 (in shares)"
       }
      }
     },
     "localname": "PreferredStockSharesOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_PreferredStockValueOutstanding": {
     "auth_ref": [
      "r14"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Value of all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by shareholders, which is net of related treasury stock. May be all or a portion of the number of preferred shares authorized. These shares represent the ownership interest of the preferred shareholders.",
        "label": "Preferred Stock, Value, Outstanding",
        "terseLabel": "Preferred stock, $0.001 par value; 5,000,000 shares authorized; no shares issued and outstanding"
       }
      }
     },
     "localname": "PreferredStockValueOutstanding",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PrepaidExpenseAndOtherAssetsCurrent": {
     "auth_ref": [
      "r3",
      "r28",
      "r29"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 5.0,
       "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",
        "terseLabel": "Prepaid expenses and other current assets"
       }
      }
     },
     "localname": "PrepaidExpenseAndOtherAssetsCurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromIssuanceInitialPublicOffering": {
     "auth_ref": [
      "r74"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 2.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash inflow associated with the amount received from entity's first offering of stock to the public.",
        "label": "Proceeds from Issuance Initial Public Offering",
        "terseLabel": "Proceeds from public offerings of common stock, net of commissions, underwriting discounts and offering costs"
       }
      }
     },
     "localname": "ProceedsFromIssuanceInitialPublicOffering",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromIssuanceOfCommonStock": {
     "auth_ref": [
      "r74"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cash inflow from the additional capital contribution to the entity.",
        "label": "Proceeds from Issuance of Common Stock",
        "verboseLabel": "Proceeds from issuance of common stock"
       }
      }
     },
     "localname": "ProceedsFromIssuanceOfCommonStock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities": {
     "auth_ref": [
      "r70",
      "r71",
      "r121"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 3.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInInvestingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cash inflow from maturity, prepayment and call of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).",
        "label": "Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities",
        "terseLabel": "Maturities of investments"
       }
      }
     },
     "localname": "ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProceedsFromPaymentsForOtherFinancingActivities": {
     "auth_ref": [
      "r75",
      "r76",
      "r92"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInFinancingActivities",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cash inflow (outflow) from financing activities classified as other.",
        "label": "Other financing activities"
       }
      }
     },
     "localname": "ProceedsFromPaymentsForOtherFinancingActivities",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ProductMember": {
     "auth_ref": [
      "r171"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Article or substance produced by nature, labor or machinery.",
        "label": "Product [Member]",
        "terseLabel": "Product revenue, net"
       }
      }
     },
     "localname": "ProductMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueDetails",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ProfitLoss": {
     "auth_ref": [
      "r56",
      "r58",
      "r77",
      "r112",
      "r113",
      "r217",
      "r218",
      "r219",
      "r221",
      "r222"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 1.0,
       "parentTag": "us-gaap_NetCashProvidedByUsedInOperatingActivities",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.",
        "label": "Net Income (Loss), Including Portion Attributable to Noncontrolling Interest",
        "terseLabel": "Net loss"
       }
      }
     },
     "localname": "ProfitLoss",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Property, Plant and Equipment [Abstract]"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentByTypeAxis": {
     "auth_ref": [
      "r32",
      "r153"
     ],
     "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]"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentByTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetEstimatedUsefulLivesDetails",
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock": {
     "auth_ref": [
      "r155"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for long-lived, physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, accounting policies and methodology, roll forwards, depreciation, depletion and amortization expense, including composite depreciation, accumulated depreciation, depletion and amortization expense, useful lives and method used, income statement disclosures, assets held for sale and public utility disclosures.",
        "label": "Property, Plant and Equipment Disclosure [Text Block]",
        "terseLabel": "Property and Equipment, Net"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNet"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives": {
     "auth_ref": [
      "r89",
      "r149"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Describes the periods of time over which an entity anticipates to receive utility from its property, plant and equipment (that is, the periods of time over which an entity allocates the initial cost of its property, plant and equipment).",
        "label": "Property, Plant and Equipment, Estimated Useful Lives",
        "terseLabel": "Estimated Useful Life"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentEstimatedUsefulLives",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetEstimatedUsefulLivesDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentGross": {
     "auth_ref": [
      "r31",
      "r151"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails": {
       "order": 2.0,
       "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": "Gross property and equipment"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentGross",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails"
     ],
     "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]"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetEstimatedUsefulLivesDetails",
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentNet": {
     "auth_ref": [
      "r11",
      "r12",
      "r153",
      "r270"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "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": "Total"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentNet",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentNetAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Property, Plant and Equipment, Net [Abstract]",
        "terseLabel": "Property and Equipment, Net"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentNetAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetEstimatedUsefulLivesDetails",
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentTextBlock": {
     "auth_ref": [
      "r11",
      "r153"
     ],
     "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": "Schedule of property and equipment"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentTypeDomain": {
     "auth_ref": [
      "r11",
      "r151"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Listing of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.",
        "label": "Property Plant And Equipment Type [Domain]",
        "terseLabel": "Property, Plant and Equipment, Type [Domain]"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetEstimatedUsefulLivesDetails",
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_PropertyPlantAndEquipmentUsefulLife": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.",
        "label": "Property, Plant and Equipment, Useful Life",
        "terseLabel": "Estimated Useful Life (Years)"
       }
      }
     },
     "localname": "PropertyPlantAndEquipmentUsefulLife",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetEstimatedUsefulLivesDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_PurchaseObligation": {
     "auth_ref": [],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Minimum amount of purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier.",
        "label": "Purchase Obligation",
        "verboseLabel": "Manufacturing purchase obligations"
       }
      }
     },
     "localname": "PurchaseObligation",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCommitmentsDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_PurchaseObligationFiscalYearMaturityAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Purchase Obligation, Fiscal Year Maturity [Abstract]",
        "terseLabel": "Commitments"
       }
      }
     },
     "localname": "PurchaseObligationFiscalYearMaturityAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCommitmentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ReceivablesTradeAndOtherAccountsReceivableAllowanceForDoubtfulAccountsPolicy": {
     "auth_ref": [
      "r22",
      "r89",
      "r117"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for determining the allowance for doubtful accounts for trade and other accounts receivable balances, and when impairments, charge-offs or recoveries are recognized.",
        "label": "Receivables, Trade and Other Accounts Receivable, Allowance for Doubtful Accounts, Policy [Policy Text Block]",
        "terseLabel": "Accounts Receivable"
       }
      }
     },
     "localname": "ReceivablesTradeAndOtherAccountsReceivableAllowanceForDoubtfulAccountsPolicy",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis": {
     "auth_ref": [
      "r208",
      "r209"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by form of arrangement related to research and development.",
        "label": "Research and Development Arrangement, Contract to Perform for Others, Type [Axis]"
       }
      }
     },
     "localname": "ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersTypeDomain": {
     "auth_ref": [
      "r208",
      "r209"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Listing of significant agreements under research and development arrangements accounted for as a contract to perform research and development for others.",
        "label": "Research And Development Arrangement Contract To Perform For Others Type [Domain]",
        "terseLabel": "Research and Development Arrangement, Contract to Perform for Others, Type [Domain]"
       }
      }
     },
     "localname": "ResearchAndDevelopmentArrangementContractToPerformForOthersTypeDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_ResearchAndDevelopmentExpense": {
     "auth_ref": [
      "r207",
      "r281"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 2.0,
       "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "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]",
        "terseLabel": "Research and development"
       }
      }
     },
     "localname": "ResearchAndDevelopmentExpenseMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RestrictedAssetsDisclosureTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for assets that are restricted in their use, generally by contractual agreements or regulatory requirements. This would include, but not limited to, a description of the restricted assets and the terms of the restriction.",
        "label": "Restricted Assets Disclosure [Text Block]",
        "terseLabel": "Restricted Cash"
       }
      }
     },
     "localname": "RestrictedAssetsDisclosureTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureRestrictedCash"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_RestrictedCash": {
     "auth_ref": [
      "r88",
      "r258",
      "r267"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.",
        "label": "Restricted Cash",
        "verboseLabel": "Restricted cash"
       }
      }
     },
     "localname": "RestrictedCash",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails",
      "http://www.blueprintmedicines.com/role/DisclosureRestrictedCashDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RestrictedCashAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Restricted Cash [Abstract]",
        "terseLabel": "Restricted Cash"
       }
      }
     },
     "localname": "RestrictedCashAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureRestrictedCashDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RestrictedCashAndCashEquivalentsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Restricted Cash and Cash Equivalents [Abstract]"
       }
      }
     },
     "localname": "RestrictedCashAndCashEquivalentsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "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": "Restricted Cash And Cash Equivalents Cash And Cash Equivalents [Member]",
        "terseLabel": "Cash and Cash Equivalents [Domain]"
       }
      }
     },
     "localname": "RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureCashEquivalentsDetails",
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RestrictedCashNoncurrent": {
     "auth_ref": [
      "r5",
      "r13",
      "r88",
      "r280"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 6.0,
       "parentTag": "us-gaap_Assets",
       "weight": 1.0
      },
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlowsParenthetical": {
       "order": 2.0,
       "parentTag": "us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents",
       "weight": 1.0
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cash restricted as to withdrawal or usage, 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.",
        "label": "Restricted Cash, Noncurrent",
        "terseLabel": "Restricted cash"
       }
      }
     },
     "localname": "RestrictedCashNoncurrent",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlowsParenthetical"
     ],
     "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 R S U [Member]",
        "terseLabel": "Restricted stock units"
       }
      }
     },
     "localname": "RestrictedStockUnitsRSUMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNetLossPerShareDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationUnrecognizedCompensationCostsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RetainedEarningsAccumulatedDeficit": {
     "auth_ref": [
      "r18",
      "r159",
      "r268"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 1.0,
       "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"
       }
      }
     },
     "localname": "RetainedEarningsAccumulatedDeficit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RetainedEarningsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The cumulative amount of the reporting entity's undistributed earnings or deficit.",
        "label": "Retained Earnings [Member]",
        "terseLabel": "Accumulated Deficit"
       }
      }
     },
     "localname": "RetainedEarningsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Revenue from Contract with Customer [Abstract]"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax": {
     "auth_ref": [
      "r166",
      "r168"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedCstoneDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      },
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 1.0,
       "parentTag": "us-gaap_NetIncomeLoss",
       "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": "Collaboration revenue",
        "totalLabel": "Total CStone collaboration revenue",
        "verboseLabel": "Total revenues"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerIncludingAssessedTax",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedCstoneDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedRocheDetails",
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueDetails",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_RevenueFromContractWithCustomerPolicyTextBlock": {
     "auth_ref": [
      "r90",
      "r172"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of accounting policy for revenue from contract with customer.",
        "label": "Revenue from Contract with Customer [Policy Text Block]",
        "terseLabel": "Product Revenue Recognition"
       }
      }
     },
     "localname": "RevenueFromContractWithCustomerPolicyTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1": {
     "auth_ref": [
      "r165"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Period in which remaining performance obligation is expected to be recognized as revenue, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.",
        "label": "Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period",
        "terseLabel": "Research and development services, performance period"
       }
      }
     },
     "localname": "RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "durationItemType"
    },
    "us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis": {
     "auth_ref": [
      "r165"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Start date of time band for expected timing of satisfaction of remaining performance obligation, in CCYY-MM-DD format.",
        "label": "Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]"
       }
      }
     },
     "localname": "RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RevenuesAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Revenues [Abstract]",
        "terseLabel": "Revenues",
        "verboseLabel": "Revenues:"
       }
      }
     },
     "localname": "RevenuesAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesProductRevenueDetails",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability": {
     "auth_ref": [
      "r247",
      "r252"
     ],
     "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": "Lease liabilities arising from obtaining right-of-use assets, operating leases"
       }
      }
     },
     "localname": "RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesCashFlowInformationDetails"
     ],
     "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 Name Of Transaction [Domain]",
        "terseLabel": "Sale of Stock [Domain]"
       }
      }
     },
     "localname": "SaleOfStockNameOfTransactionDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNatureOfBusinessSaleOfStockDetails"
     ],
     "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": "Schedule of accrued expenses"
       }
      }
     },
     "localname": "ScheduleOfAccruedLiabilitiesTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable": {
     "auth_ref": [
      "r98"
     ],
     "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]"
       }
      }
     },
     "localname": "ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNetLossPerShareDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock": {
     "auth_ref": [
      "r98"
     ],
     "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": "Schedule of common stock equivalents excluded from calculation of diluted net loss per share applicable to common stockholders"
       }
      }
     },
     "localname": "ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNetLossPerShareTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfCashAndCashEquivalentsTable": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule of cash and cash equivalent balances. This table excludes restricted cash balances.",
        "label": "Schedule of Cash and Cash Equivalents [Table]"
       }
      }
     },
     "localname": "ScheduleOfCashAndCashEquivalentsTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureCashEquivalentsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfCashCashEquivalentsAndShortTermInvestmentsTableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the components of cash, cash equivalents, and investments.",
        "label": "Cash, Cash Equivalents and Investments [Table Text Block]",
        "terseLabel": "Schedule of cash equivalents and investments, available-for-sale"
       }
      }
     },
     "localname": "ScheduleOfCashCashEquivalentsAndShortTermInvestmentsTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable": {
     "auth_ref": [
      "r213"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about collaborative arrangement and arrangement other than collaborative applicable to revenue-generating activity or operations.",
        "label": "Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions [Table]"
       }
      }
     },
     "localname": "ScheduleOfCollaborativeArrangementsAndNoncollaborativeArrangementTransactionsTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsContractAssetsCstoneDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsManufacturingServicesDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedCstoneDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedRocheDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable": {
     "auth_ref": [
      "r178",
      "r198",
      "r203"
     ],
     "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]"
       }
      }
     },
     "localname": "ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock": {
     "auth_ref": [
      "r178",
      "r198",
      "r203"
     ],
     "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": "Summary of stock-based compensation expense, allocation by type of awards and recognition in statements of operations"
       }
      }
     },
     "localname": "ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfInventoryCurrentTableTextBlock": {
     "auth_ref": [
      "r9",
      "r25",
      "r26",
      "r27"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the carrying amount as of the balance sheet date of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.",
        "label": "Schedule of Inventory, Current [Table Text Block]",
        "terseLabel": "Schedule of capitalized inventory"
       }
      }
     },
     "localname": "ScheduleOfInventoryCurrentTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureInventoryTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Net Investment Income [Line Items]"
       }
      }
     },
     "localname": "ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureInvestmentsAvailableForSaleDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryTable": {
     "auth_ref": [
      "r66",
      "r68",
      "r69",
      "r273"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Disclosure of information about investment income, including, but not limited to, interest and dividend income and amortization of discount (premium) derived from debt and equity securities. Excludes realized and unrealized gain (loss) on investments.",
        "label": "Investment Income [Table]"
       }
      }
     },
     "localname": "ScheduleOfInvestmentIncomeReportedAmountsByCategoryTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureInvestmentsAvailableForSaleDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock": {
     "auth_ref": [
      "r188"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Tabular disclosure of the changes in outstanding nonvested restricted stock units.",
        "label": "Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]",
        "terseLabel": "Summary of restricted stock units activity"
       }
      }
     },
     "localname": "ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_ScheduleOfPropertyPlantAndEquipmentTable": {
     "auth_ref": [
      "r32",
      "r153"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetEstimatedUsefulLivesDetails",
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable": {
     "auth_ref": [
      "r180",
      "r202"
     ],
     "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]"
       }
      }
     },
     "localname": "ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2015StockOptionAndIncentivePlanDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2020InducementPlanDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationEmployeeStockPurchasePlanDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationUnrecognizedCompensationCostsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock": {
     "auth_ref": [
      "r183",
      "r193",
      "r195"
     ],
     "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": "Summary of stock option activity"
       }
      }
     },
     "localname": "ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationTables"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SecurityDeposit": {
     "auth_ref": [
      "r45"
     ],
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The amount of an asset, typically cash, provided to a counterparty to provide certain assurance of performance by the entity pursuant to the terms of a written or oral agreement, such as a lease.",
        "label": "Security Deposit",
        "terseLabel": "Security deposit"
       }
      }
     },
     "localname": "SecurityDeposit",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesGeneralInformationDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_SellingGeneralAndAdministrativeExpense": {
     "auth_ref": [
      "r65",
      "r140"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss": {
       "order": 3.0,
       "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",
        "verboseLabel": "Selling, general and administrative"
       }
      }
     },
     "localname": "SellingGeneralAndAdministrativeExpense",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensation": {
     "auth_ref": [
      "r80"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows": {
       "order": 9.0,
       "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]",
        "terseLabel": "Stock-based compensation"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardAdditionalGeneralDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2015StockOptionAndIncentivePlanDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2020InducementPlanDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationEmployeeStockPurchasePlanDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod": {
     "auth_ref": [
      "r187"
     ],
     "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": "Forfeited (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r192"
     ],
     "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": "Forfeited (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod": {
     "auth_ref": [
      "r190"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period",
        "terseLabel": "Granted (in shares)",
        "verboseLabel": "Shares granted, other than options (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2020InducementPlanDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r190"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value",
        "terseLabel": "Granted (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber": {
     "auth_ref": [
      "r189"
     ],
     "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": "Unvested at end of period (in shares)",
        "periodStartLabel": "Unvested at beginning of period (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]",
        "terseLabel": "Shares"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r189"
     ],
     "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": "Unvested at end of period (in dollars per share)",
        "periodStartLabel": "Unvested at beginning or period (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]",
        "terseLabel": "Weighted-Average Grant Date Fair Value"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod": {
     "auth_ref": [
      "r191"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period",
        "negatedLabel": "Vested (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue": {
     "auth_ref": [
      "r191"
     ],
     "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": "Vested (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award [Line Items]"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2015StockOptionAndIncentivePlanDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2020InducementPlanDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationEmployeeStockPurchasePlanDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationUnrecognizedCompensationCostsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of additional shares authorized for issuance under share-based payment arrangement.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized",
        "terseLabel": "Increase in number of shares available for grant"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2015StockOptionAndIncentivePlanDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized": {
     "auth_ref": [
      "r181"
     ],
     "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": "Initial shares of common stock authorized for issuance of stock awards (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2015StockOptionAndIncentivePlanDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2020InducementPlanDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant": {
     "auth_ref": [
      "r202"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant",
        "terseLabel": "Number of shares available for grant"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2015StockOptionAndIncentivePlanDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]",
        "terseLabel": "Additional disclosures"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockOptionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Gross number of share options (or share units) granted during the period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross",
        "terseLabel": "Granted (in shares)",
        "verboseLabel": "Shares granted, options (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensation2020InducementPlanDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockOptionsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOtherIncreasesDecreasesInPeriod": {
     "auth_ref": [
      "r183"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The addition or reduction in the number of reserved shares that could potentially be issued under the option plan attributable to reasons other than grants, exercises, forfeitures, and expirations during the reporting period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Other Increases (Decreases) in Period",
        "negatedLabel": "Cancelled (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOtherIncreasesDecreasesInPeriod",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockOptionsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber": {
     "auth_ref": [
      "r185",
      "r202"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of options outstanding, including both vested and non-vested options.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number",
        "periodEndLabel": "Outstanding at end of period (in shares)",
        "periodStartLabel": "Outstanding at beginning of period (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockOptionsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]",
        "terseLabel": "Shares"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockOptionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice": {
     "auth_ref": [
      "r184"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price",
        "periodEndLabel": "Outstanding at end of period (in dollars per share)",
        "periodStartLabel": "Outstanding at beginning of period (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockOptionsDetails"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockOptionsDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber": {
     "auth_ref": [
      "r196"
     ],
     "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": "Shares - Exercisable (in shares)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockOptionsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice": {
     "auth_ref": [
      "r196"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest exercisable or convertible options. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.",
        "label": "Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Exercise Price",
        "terseLabel": "Weighted-Average Exercise Price - Exercisable (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockOptionsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain": {
     "auth_ref": [
      "r177",
      "r182"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Award under share-based payment arrangement.",
        "label": "Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain]",
        "terseLabel": "Equity Award [Domain]"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationEmployeeStockPurchasePlanDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationRestrictedStockUnitsDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationUnrecognizedCompensationCostsDetails"
     ],
     "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": "Exercised (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockOptionsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.",
        "label": "Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price",
        "terseLabel": "Granted (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockOptionsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsOtherShareIncreaseDecreaseInPeriodWeightedAverageExercisePrice": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Weighted average price at which grantees could acquire or could have acquired the underlying shares with respect to any other type of change in shares reserved for issuance.",
        "label": "Share-based Compensation Arrangements by Share-based Payment Award, Options, Other Share Increase (Decrease) in Period, Weighted Average Exercise Price",
        "terseLabel": "Cancelled (in dollars per share)"
       }
      }
     },
     "localname": "ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsOtherShareIncreaseDecreaseInPeriodWeightedAverageExercisePrice",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockOptionsDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "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",
        "terseLabel": "Share price (in dollars per share)"
       }
      }
     },
     "localname": "SharePrice",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNatureOfBusinessSaleOfStockDetails"
     ],
     "xbrltype": "perShareItemType"
    },
    "us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardCompensationCost1": {
     "auth_ref": [
      "r198"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails": {
       "order": null,
       "parentTag": null,
       "root": true,
       "weight": null
      }
     },
     "crdr": "debit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of cost expensed and capitalized for award under share-based payment arrangement.",
        "label": "Share-based Payment Arrangement, Expensed and Capitalized, Amount",
        "totalLabel": "Subtotal"
       }
      }
     },
     "localname": "SharebasedCompensationArrangementBySharebasedPaymentAwardCompensationCost1",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_SoftwareAndSoftwareDevelopmentCostsMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Purchased software applications and internally developed software for sale, licensing or long-term internal use.",
        "label": "Software And Software Development Costs [Member]",
        "terseLabel": "Software"
       }
      }
     },
     "localname": "SoftwareAndSoftwareDevelopmentCostsMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetEstimatedUsefulLivesDetails",
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetPropertyAndEquipmentAndRelatedAccumulatedDepreciationDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_StatementEquityComponentsAxis": {
     "auth_ref": [
      "r42",
      "r158"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by component of equity.",
        "label": "Equity Components [Axis]"
       }
      }
     },
     "localname": "StatementEquityComponentsAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "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]"
       }
      }
     },
     "localname": "StatementLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxesDetails",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "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/2019-01-31",
     "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/2019-01-31",
     "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/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_StatementTable": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Schedule reflecting a Statement of Income, Statement of Cash Flows, Statement of Financial Position, Statement of Shareholders' Equity and Other Comprehensive Income, or other statement as needed.",
        "label": "Statement [Table]"
       }
      }
     },
     "localname": "StatementTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureIncomeTaxesDetails",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_StockIssuedDuringPeriodSharesNewIssues": {
     "auth_ref": [
      "r14",
      "r15",
      "r158",
      "r159"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number of new stock issued during the period.",
        "label": "Stock Issued During Period, Shares, New Issues",
        "terseLabel": "Stock sold (in shares)",
        "verboseLabel": "Initial public offering / Follow on offering, net of issuance costs (in shares)"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodSharesNewIssues",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNatureOfBusinessSaleOfStockDetails",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation": {
     "auth_ref": [
      "r14",
      "r15",
      "r158",
      "r159"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Number, after forfeiture, of shares or units issued under share-based payment arrangement. Excludes shares or units issued under employee stock ownership plan (ESOP).",
        "label": "Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures",
        "terseLabel": "Issuance of common stock under stock plan (in shares)"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodSharesShareBasedCompensation",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised": {
     "auth_ref": [
      "r14",
      "r15",
      "r158",
      "r159",
      "r186"
     ],
     "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": "Exercised (in shares)"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodSharesStockOptionsExercised",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationStockOptionsDetails"
     ],
     "xbrltype": "sharesItemType"
    },
    "us-gaap_StockIssuedDuringPeriodValueNewIssues": {
     "auth_ref": [
      "r14",
      "r15",
      "r158",
      "r159"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.",
        "label": "Stock Issued During Period, Value, New Issues",
        "terseLabel": "Initial public offering / Follow on offering, net of issuance costs"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodValueNewIssues",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation": {
     "auth_ref": [
      "r14",
      "r15",
      "r159",
      "r179",
      "r194"
     ],
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Value, after forfeiture, of shares issued under share-based payment arrangement. Excludes employee stock ownership plan (ESOP).",
        "label": "Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures",
        "terseLabel": "Issuance of common stock under stock plan"
       }
      }
     },
     "localname": "StockIssuedDuringPeriodValueShareBasedCompensation",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_StockholdersEquity": {
     "auth_ref": [
      "r15",
      "r19",
      "r20",
      "r118"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets": {
       "order": 1.0,
       "parentTag": "us-gaap_LiabilitiesAndStockholdersEquity",
       "weight": 1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.",
        "label": "Stockholders' Equity Attributable to Parent",
        "periodEndLabel": "Ending Balance",
        "periodStartLabel": "Beginning Balance",
        "totalLabel": "Total stockholders' equity"
       }
      }
     },
     "localname": "StockholdersEquity",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets",
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfStockholdersEquity"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedBalanceSheets"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SubleaseIncome": {
     "auth_ref": [
      "r245",
      "r252"
     ],
     "calculation": {
      "http://www.blueprintmedicines.com/role/DisclosureLeasesComponentsOfLeaseExpenseDetails": {
       "order": 2.0,
       "parentTag": "us-gaap_LeaseCost",
       "weight": -1.0
      }
     },
     "crdr": "credit",
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Amount of sublease income excluding finance and operating lease expense.",
        "label": "Sublease Income",
        "negatedLabel": "Sublease income"
       }
      }
     },
     "localname": "SubleaseIncome",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureLeasesComponentsOfLeaseExpenseDetails"
     ],
     "xbrltype": "monetaryItemType"
    },
    "us-gaap_SubsequentEventsAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Subsequent Events [Abstract]"
       }
      }
     },
     "localname": "SubsequentEventsAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "xbrltype": "stringItemType"
    },
    "us-gaap_SubsequentEventsTextBlock": {
     "auth_ref": [
      "r254"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business.",
        "label": "Subsequent Events [Text Block]",
        "terseLabel": "Subsequent Events"
       }
      }
     },
     "localname": "SubsequentEventsTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSubsequentEvents"
     ],
     "xbrltype": "textBlockItemType"
    },
    "us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Different names of stock transactions and the different attributes of each transaction.",
        "label": "Subsidiary or Equity Method Investee, Sale of Stock by Subsidiary or Equity Investee [Table]"
       }
      }
     },
     "localname": "SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNatureOfBusinessSaleOfStockDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "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]"
       }
      }
     },
     "localname": "SubsidiarySaleOfStockAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNatureOfBusinessSaleOfStockDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SubsidiarySaleOfStockLineItems": {
     "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": "Subsidiary, Sale of Stock [Line Items]",
        "terseLabel": "Nature of Business"
       }
      }
     },
     "localname": "SubsidiarySaleOfStockLineItems",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureNatureOfBusinessSaleOfStockDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_SupplementalCashFlowInformationAbstract": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Supplemental Cash Flow Information [Abstract]",
        "terseLabel": "Supplemental cash flow information"
       }
      }
     },
     "localname": "SupplementalCashFlowInformationAbstract",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfCashFlows"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_TableTextBlock": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "label": "Table Text Block [Abstract]",
        "terseLabel": "Table Text Blocks"
       }
      }
     },
     "localname": "TableTextBlock",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureAccruedExpensesTables",
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTables",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsTables",
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsTables",
      "http://www.blueprintmedicines.com/role/DisclosureInventoryTables",
      "http://www.blueprintmedicines.com/role/DisclosureLeasesTables",
      "http://www.blueprintmedicines.com/role/DisclosureNetLossPerShareTables",
      "http://www.blueprintmedicines.com/role/DisclosureProductRevenueReservesAndAllowancesTables",
      "http://www.blueprintmedicines.com/role/DisclosurePropertyAndEquipmentNetTables",
      "http://www.blueprintmedicines.com/role/DisclosureStockBasedCompensationTables"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_TypeOfAdoptionMember": {
     "auth_ref": [],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Adoption and early adoption of sources of change to generally accepted accounting principles (GAAP) in the United States. The FASB released the FASB Accounting Standards Codification as the authoritative source of literature effective for interim and annual periods ending after September 15, 2009. As part of the Codification process, the FASB issues Accounting Standards Updates to amend the Codification but otherwise the Accounting Standards Updates are not authoritative in their own right. All previous accounting standards (such as FASB Statements of Financial Accounting Standards, FASB Interpretations, FASB Staff Positions, Emerging Issues Task Force Consensuses, other pronouncements of the FASB or other designated bodies, or other forms of GAAP are considered accounting pronouncements) were superseded upon the adoption of the Codification. For an interim period, references to the superseded standards are included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.",
        "label": "Type Of Adoption [Member]",
        "terseLabel": "Type of Adoption [Domain]"
       }
      }
     },
     "localname": "TypeOfAdoptionMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNewAccountingPronouncementsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_TypeOfArrangementAxis": {
     "auth_ref": [
      "r213"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "Information by collaborative arrangement and arrangement other than collaborative applicable to revenue-generating activity or operations.",
        "label": "Type of Arrangement and Non-arrangement Transactions [Axis]"
       }
      }
     },
     "localname": "TypeOfArrangementAxis",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsContractAssetsCstoneDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsGeneralInformationDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsManufacturingServicesDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedCstoneDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCollaborationAndLicenseAgreementsRevenueRecognizedRocheDetails"
     ],
     "xbrltype": "stringItemType"
    },
    "us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember": {
     "auth_ref": [
      "r263"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This category includes information about debt issued by US Government Corporations and Agencies. Investments in such US Government Corporations may include debt securities issued by the Government National Mortgage Association (Ginnie Mae) and by the Federal National Mortgage Association (Fannie Mae) and the Federal Home Loan Mortgage Corporation (Freddie Mac).",
        "label": "U S Government Corporations And Agencies Securities [Member]",
        "terseLabel": "U.S. government agency securities"
       }
      }
     },
     "localname": "USGovernmentCorporationsAndAgenciesSecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureInvestmentsAvailableForSaleDetails",
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_USTreasurySecuritiesMember": {
     "auth_ref": [
      "r173",
      "r175",
      "r261"
     ],
     "lang": {
      "en-US": {
       "role": {
        "documentation": "This category includes information about debt securities issued by the United States Department of the Treasury and backed by the United States government. Such securities primarily consist of treasury bills (short-term maturities - one year or less), treasury notes (intermediate term maturities - two to ten years), and treasury bonds (long-term maturities - ten to thirty years).",
        "label": "U S Treasury Securities [Member]",
        "terseLabel": "U.S. Treasury obligations"
       }
      }
     },
     "localname": "USTreasurySecuritiesMember",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureCashEquivalentsDetails",
      "http://www.blueprintmedicines.com/role/DisclosureCashEquivalentsAndInvestmentsTabularDisclosureInvestmentsAvailableForSaleDetails",
      "http://www.blueprintmedicines.com/role/DisclosureFairValueOfFinancialInstrumentsDetails"
     ],
     "xbrltype": "domainItemType"
    },
    "us-gaap_UseOfEstimates": {
     "auth_ref": [
      "r103",
      "r104",
      "r105",
      "r106",
      "r107",
      "r108",
      "r109"
     ],
     "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/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsPolicies"
     ],
     "xbrltype": "textBlockItemType"
    },
    "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 common shares used in net loss per share - basic and diluted"
       }
      }
     },
     "localname": "WeightedAverageNumberOfShareOutstandingBasicAndDiluted",
     "nsuri": "http://fasb.org/us-gaap/2019-01-31",
     "presentation": [
      "http://www.blueprintmedicines.com/role/StatementCondensedConsolidatedStatementsOfOperationsAndComprehensiveLoss"
     ],
     "xbrltype": "sharesItemType"
    }
   },
   "unitCount": 7
  }
 },
 "std_ref": {
  "r0": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765"
  },
  "r1": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765"
  },
  "r10": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(1))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r100": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "260",
   "URI": "http://asc.fasb.org/topic&trid=2144383"
  },
  "r101": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "270",
   "URI": "http://asc.fasb.org/extlink&oid=116846552&loc=d3e543-108305"
  },
  "r102": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "275",
   "URI": "http://asc.fasb.org/extlink&oid=99393423&loc=d3e5967-108592"
  },
  "r103": {
   "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"
  },
  "r104": {
   "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"
  },
  "r105": {
   "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"
  },
  "r106": {
   "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"
  },
  "r107": {
   "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"
  },
  "r108": {
   "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"
  },
  "r109": {
   "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"
  },
  "r11": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(13))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r110": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "275",
   "URI": "http://asc.fasb.org/topic&trid=2134479"
  },
  "r111": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599"
  },
  "r112": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "22",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599"
  },
  "r113": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "32",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e8933-108599"
  },
  "r114": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "40",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "280",
   "URI": "http://asc.fasb.org/extlink&oid=115929826&loc=d3e9031-108599"
  },
  "r115": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=118952595&loc=d3e4428-111522"
  },
  "r116": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=118952595&loc=d3e4531-111522"
  },
  "r117": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "310",
   "URI": "http://asc.fasb.org/extlink&oid=118936363&loc=d3e5144-111524"
  },
  "r118": {
   "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"
  },
  "r119": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "310",
   "URI": "http://asc.fasb.org/topic&trid=2196771"
  },
  "r12": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(14))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r120": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=118954083&loc=d3e26610-111562"
  },
  "r121": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=118954083&loc=d3e26853-111562"
  },
  "r122": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=118954083&loc=d3e26626-111562"
  },
  "r123": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563"
  },
  "r124": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(aa)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563"
  },
  "r125": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563"
  },
  "r126": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563"
  },
  "r127": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(2)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=118939692&loc=d3e27290-111563"
  },
  "r128": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(3)",
   "Topic": "320",
   "URI": "http://asc.fasb.org/extlink&oid=118939692&loc=d3e27290-111563"
  },
  "r129": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "320",
   "URI": "http://asc.fasb.org/topic&trid=2196928"
  },
  "r13": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(17))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r130": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=118950378&loc=SL82887624-210437"
  },
  "r131": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=118955202&loc=SL82895884-210446"
  },
  "r132": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447"
  },
  "r133": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447"
  },
  "r134": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(e)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447"
  },
  "r135": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(f)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447"
  },
  "r136": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447"
  },
  "r137": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=118942338&loc=SL82898722-210454"
  },
  "r138": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(a)(2)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=118955579&loc=SL82922888-210455"
  },
  "r139": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "30",
   "Subparagraph": "(b)(3)",
   "Topic": "326",
   "URI": "http://asc.fasb.org/extlink&oid=118955579&loc=SL82922888-210455"
  },
  "r14": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(28))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r140": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "30",
   "SubTopic": "10",
   "Topic": "330",
   "URI": "http://asc.fasb.org/extlink&oid=68048583&loc=d3e3636-108311"
  },
  "r141": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "35",
   "SubTopic": "10",
   "Topic": "330",
   "URI": "http://asc.fasb.org/extlink&oid=116846819&loc=d3e3927-108312"
  },
  "r142": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "330",
   "URI": "http://asc.fasb.org/extlink&oid=116847112&loc=d3e4492-108314"
  },
  "r143": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "330",
   "URI": "http://asc.fasb.org/extlink&oid=116847112&loc=d3e4542-108314"
  },
  "r144": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "330",
   "URI": "http://asc.fasb.org/extlink&oid=116847112&loc=d3e4556-108314"
  },
  "r145": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SAB Topic 5.BB)",
   "Topic": "330",
   "URI": "http://asc.fasb.org/extlink&oid=27011343&loc=d3e100047-122729"
  },
  "r146": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "330",
   "URI": "http://asc.fasb.org/topic&trid=2126998"
  },
  "r147": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(e)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=118172025&loc=SL118172731-207502"
  },
  "r148": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "40",
   "Subparagraph": "(f)",
   "Topic": "350",
   "URI": "http://asc.fasb.org/extlink&oid=118172025&loc=SL118172731-207502"
  },
  "r149": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "35",
   "SubTopic": "10",
   "Topic": "360",
   "URI": "http://asc.fasb.org/extlink&oid=68071081&loc=d3e1205-110223"
  },
  "r15": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(29))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r150": {
   "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"
  },
  "r151": {
   "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"
  },
  "r152": {
   "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"
  },
  "r153": {
   "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"
  },
  "r154": {
   "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"
  },
  "r155": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "360",
   "URI": "http://asc.fasb.org/topic&trid=2155823"
  },
  "r156": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "440",
   "URI": "http://asc.fasb.org/topic&trid=2144648"
  },
  "r157": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "450",
   "URI": "http://asc.fasb.org/extlink&oid=118942415&loc=d3e14326-108349"
  },
  "r158": {
   "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"
  },
  "r159": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.3-04)",
   "Topic": "505",
   "URI": "http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770"
  },
  "r16": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(3))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r160": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118944033&loc=SL49130531-203044"
  },
  "r161": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118944033&loc=SL49130532-203044"
  },
  "r162": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118944033&loc=SL49130533-203044"
  },
  "r163": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130551-203045"
  },
  "r164": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130551-203045"
  },
  "r165": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)(1)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130556-203045"
  },
  "r166": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045"
  },
  "r167": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045"
  },
  "r168": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045"
  },
  "r169": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130549-203045"
  },
  "r17": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r170": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118956577&loc=SL49130549-203045"
  },
  "r171": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "91",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "606",
   "URI": "http://asc.fasb.org/extlink&oid=118944142&loc=SL49130690-203046-203046"
  },
  "r172": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "606",
   "URI": "http://asc.fasb.org/topic&trid=49130388"
  },
  "r173": {
   "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"
  },
  "r174": {
   "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"
  },
  "r175": {
   "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"
  },
  "r176": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "35",
   "SubTopic": "10",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116855982&loc=d3e4534-113899"
  },
  "r177": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901"
  },
  "r178": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901"
  },
  "r179": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901"
  },
  "r18": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(30)(a)(3))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r180": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901"
  },
  "r181": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(3)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r182": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a),(g)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r183": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r184": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(i)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r185": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(i)-(ii)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r186": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(iv)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r187": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)(iv)(3)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r188": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r189": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)(i)-(ii)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r19": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r190": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)(iii)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r191": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)(iii)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r192": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(2)(iii)(3)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r193": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r194": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r195": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r196": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)(2)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r197": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(g)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r198": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)(1)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r199": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(h)(1)(i)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r2": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765"
  },
  "r20": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r200": {
   "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=116856206&loc=d3e5070-113901"
  },
  "r201": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(i)",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r202": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901"
  },
  "r203": {
   "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"
  },
  "r204": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=118258462&loc=d3e11149-113907"
  },
  "r205": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "718",
   "URI": "http://asc.fasb.org/extlink&oid=118258462&loc=d3e11178-113907"
  },
  "r206": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "718",
   "URI": "http://asc.fasb.org/topic&trid=2228938"
  },
  "r207": {
   "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"
  },
  "r208": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "730",
   "URI": "http://asc.fasb.org/extlink&oid=6420387&loc=d3e23199-108380"
  },
  "r209": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "730",
   "URI": "http://asc.fasb.org/extlink&oid=6420387&loc=d3e23221-108380"
  },
  "r21": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(32))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r210": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "740",
   "URI": "http://asc.fasb.org/topic&trid=2144680"
  },
  "r211": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "808",
   "URI": "http://asc.fasb.org/extlink&oid=6931272&loc=SL5834143-161434"
  },
  "r212": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "808",
   "URI": "http://asc.fasb.org/extlink&oid=6931272&loc=SL5834143-161434"
  },
  "r213": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "808",
   "URI": "http://asc.fasb.org/extlink&oid=6931272&loc=SL5834143-161434"
  },
  "r214": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "808",
   "URI": "http://asc.fasb.org/extlink&oid=118645555&loc=SL118645700-161420"
  },
  "r215": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Subparagraph": "(g)",
   "Topic": "808",
   "URI": "http://asc.fasb.org/extlink&oid=118645555&loc=SL118645700-161420"
  },
  "r216": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "808",
   "URI": "http://asc.fasb.org/topic&trid=5833765"
  },
  "r217": {
   "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"
  },
  "r218": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)(1)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684"
  },
  "r219": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(c)(1)",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684"
  },
  "r22": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(4))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r220": {
   "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"
  },
  "r221": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4J",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116874947&loc=SL4591551-111686"
  },
  "r222": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4K",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "10",
   "Topic": "810",
   "URI": "http://asc.fasb.org/extlink&oid=116874947&loc=SL4591552-111686"
  },
  "r223": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "810",
   "URI": "http://asc.fasb.org/topic&trid=2197479"
  },
  "r224": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4A",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959"
  },
  "r225": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4B",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(d)",
   "Topic": "815",
   "URI": "http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959"
  },
  "r226": {
   "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"
  },
  "r227": {
   "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"
  },
  "r228": {
   "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"
  },
  "r229": {
   "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"
  },
  "r23": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(6)(a)(1))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r230": {
   "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"
  },
  "r231": {
   "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"
  },
  "r232": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2C",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117815213&loc=SL7498348-110258"
  },
  "r233": {
   "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"
  },
  "r234": {
   "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"
  },
  "r235": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "65",
   "SubTopic": "10",
   "Topic": "820",
   "URI": "http://asc.fasb.org/extlink&oid=117817908&loc=SL117819236-161440"
  },
  "r236": {
   "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"
  },
  "r237": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "20",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "30",
   "Subparagraph": "(b,c)",
   "Topic": "830",
   "URI": "http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900"
  },
  "r238": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "840",
   "URI": "http://asc.fasb.org/extlink&oid=77902758&loc=d3e41502-112717"
  },
  "r239": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(a)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977"
  },
  "r24": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r240": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977"
  },
  "r241": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "20",
   "Subparagraph": "(c)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888419&loc=SL77918643-209977"
  },
  "r242": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(a)(3)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980"
  },
  "r243": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980"
  },
  "r244": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(b)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r245": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(e)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r246": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(1)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r247": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(2)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r248": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(3)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r249": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(g)(4)",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r25": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(6)(a))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r250": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918686-209980"
  },
  "r251": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888426&loc=SL77918701-209980"
  },
  "r252": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "53",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/extlink&oid=77888399&loc=SL77918982-209971"
  },
  "r253": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "SubTopic": "20",
   "Topic": "842",
   "URI": "http://asc.fasb.org/subtopic&trid=77888251"
  },
  "r254": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "855",
   "URI": "http://asc.fasb.org/topic&trid=2122774"
  },
  "r255": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=118948506&loc=d3e107207-111719"
  },
  "r256": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)(1)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=118948506&loc=d3e107207-111719"
  },
  "r257": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "20",
   "Subparagraph": "(bb)(2)",
   "Topic": "860",
   "URI": "http://asc.fasb.org/extlink&oid=118948506&loc=d3e107207-111719"
  },
  "r258": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(1)(a))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
  },
  "r259": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(11))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
  },
  "r26": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(6)(b))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r260": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(23))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
  },
  "r261": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03(6)(a)(1))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
  },
  "r262": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.17)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
  },
  "r263": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.9-03.6(a)(1))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878"
  },
  "r264": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04(22))",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=116637391&loc=SL114874048-224260"
  },
  "r265": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.9-04.10)",
   "Topic": "942",
   "URI": "http://asc.fasb.org/extlink&oid=116637391&loc=SL114874048-224260"
  },
  "r266": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(12))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910"
  },
  "r267": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(2))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910"
  },
  "r268": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(23)(a)(4))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910"
  },
  "r269": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(25))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910"
  },
  "r27": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(6)(c))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r270": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03(a)(8))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910"
  },
  "r271": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "210",
   "Subparagraph": "(SX 210.7-03.(a),19)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910"
  },
  "r272": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04(18))",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=116637232&loc=SL114874131-224263"
  },
  "r273": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "220",
   "Subparagraph": "(SX 210.7-04.2)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=116637232&loc=SL114874131-224263"
  },
  "r274": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4H",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "40",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=116884468&loc=SL65671331-158438"
  },
  "r275": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13H",
   "Publisher": "FASB",
   "Section": "55",
   "SubTopic": "40",
   "Subparagraph": "(a)",
   "Topic": "944",
   "URI": "http://asc.fasb.org/extlink&oid=117419784&loc=SL117783719-158441"
  },
  "r276": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-12(2)(i))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611133-123010"
  },
  "r277": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-12C(1)(a))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611225-123010"
  },
  "r278": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-13(1))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611282-123010"
  },
  "r279": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "320",
   "Subparagraph": "(SX 210.12-15(Column A))",
   "Topic": "946",
   "URI": "http://asc.fasb.org/extlink&oid=50485924&loc=d3e611379-123010"
  },
  "r28": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r280": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "210",
   "Topic": "954",
   "URI": "http://asc.fasb.org/extlink&oid=116631420&loc=SL116631458-115580"
  },
  "r281": {
   "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"
  },
  "r282": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b"
  },
  "r283": {
   "Name": "Exchange Act",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "d1-1"
  },
  "r284": {
   "Name": "Form 10-Q",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "13",
   "Subsection": "a-13"
  },
  "r285": {
   "Name": "Forms 10-K, 10-Q, 20-F",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "13",
   "Subsection": "a-1-"
  },
  "r286": {
   "Name": "Regulation 12B",
   "Number": "240",
   "Publisher": "SEC",
   "Section": "12",
   "Subsection": "b-2"
  },
  "r287": {
   "Name": "Regulation S-T",
   "Number": "232",
   "Publisher": "SEC",
   "Section": "405"
  },
  "r29": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02(8))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r3": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765"
  },
  "r30": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.1)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r31": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.13)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r32": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.14)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r33": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.17)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r34": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.19(a))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r35": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.19(a),20,24)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r36": {
   "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=6877327&loc=d3e13212-122682"
  },
  "r37": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.20)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r38": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.21)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r39": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.24)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r4": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6801-107765"
  },
  "r40": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.25)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r41": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.29)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r42": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.29-31)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r43": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.6(a))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r44": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.6(b))",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r45": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.8,17)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r46": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-02.9)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682"
  },
  "r47": {
   "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"
  },
  "r48": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580"
  },
  "r49": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580"
  },
  "r5": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6812-107765"
  },
  "r50": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(f)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580"
  },
  "r51": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "10A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580"
  },
  "r52": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e637-108580"
  },
  "r53": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e681-108580"
  },
  "r54": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669686-108580"
  },
  "r55": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "17B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL34724394-108580"
  },
  "r56": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669619-108580"
  },
  "r57": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1A",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669619-108580"
  },
  "r58": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669625-108580"
  },
  "r59": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1B",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=SL7669625-108580"
  },
  "r6": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "6",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6911-107765"
  },
  "r60": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=118930883&loc=d3e557-108580"
  },
  "r61": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(20))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r62": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03(4))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r63": {
   "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=116634182&loc=SL114868664-224227"
  },
  "r64": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.2(a),(d))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r65": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.4)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r66": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.7(a),(b))",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r67": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.7)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r68": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.8)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r69": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.5-03.9)",
   "Topic": "220",
   "URI": "http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227"
  },
  "r7": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e6935-107765"
  },
  "r70": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "11",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3151-108585"
  },
  "r71": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "12",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3179-108585"
  },
  "r72": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585"
  },
  "r73": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "13",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(c)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585"
  },
  "r74": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3255-108585"
  },
  "r75": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "14",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3255-108585"
  },
  "r76": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "15",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585"
  },
  "r77": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3000-108585"
  },
  "r78": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "24",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3521-108585"
  },
  "r79": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "25",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3536-108585"
  },
  "r8": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "9",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "210",
   "URI": "http://asc.fasb.org/extlink&oid=118951113&loc=d3e7018-107765"
  },
  "r80": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(a)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585"
  },
  "r81": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Subparagraph": "(b)",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585"
  },
  "r82": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "28",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585"
  },
  "r83": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=118932676&loc=d3e3044-108585"
  },
  "r84": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "2",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=98513485&loc=d3e4297-108586"
  },
  "r85": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586"
  },
  "r86": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=98513485&loc=d3e4313-108586"
  },
  "r87": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "5",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586"
  },
  "r88": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "8",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "230",
   "URI": "http://asc.fasb.org/extlink&oid=98513485&loc=SL98516268-108586"
  },
  "r89": {
   "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"
  },
  "r9": {
   "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"
  },
  "r90": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "4",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Subparagraph": "(e)",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=84158767&loc=d3e18823-107790"
  },
  "r91": {
   "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=26873400&loc=d3e23780-122690"
  },
  "r92": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "3",
   "Publisher": "FASB",
   "Section": "S99",
   "SubTopic": "10",
   "Subparagraph": "(SX 210.12-04(a))",
   "Topic": "235",
   "URI": "http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690"
  },
  "r93": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "235",
   "URI": "http://asc.fasb.org/topic&trid=2122369"
  },
  "r94": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "250",
   "URI": "http://asc.fasb.org/extlink&oid=109234566&loc=d3e22499-107794"
  },
  "r95": {
   "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"
  },
  "r96": {
   "Name": "Accounting Standards Codification",
   "Publisher": "FASB",
   "Topic": "250",
   "URI": "http://asc.fasb.org/topic&trid=2122394"
  },
  "r97": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "7",
   "Publisher": "FASB",
   "Section": "45",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=117326831&loc=d3e1337-109256"
  },
  "r98": {
   "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"
  },
  "r99": {
   "Name": "Accounting Standards Codification",
   "Paragraph": "1",
   "Publisher": "FASB",
   "Section": "50",
   "SubTopic": "10",
   "Topic": "260",
   "URI": "http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257"
  }
 },
 "version": "2.1"
}
