3.20.1 html 80 263 1 false 26 0 false 6 false false R1.htm 00090 - Document - Document and Entity Information Sheet http://www.passagebio.com/role/DocumentDocumentAndEntityInformation Document and Entity Information Cover 1 false false R2.htm 00100 - Statement - Balance Sheets (unaudited) Sheet http://www.passagebio.com/role/StatementBalanceSheetsUnaudited Balance Sheets (unaudited) Statements 2 false false R3.htm 00105 - Statement - Balance Sheets (unaudited) (Parenthetical) Sheet http://www.passagebio.com/role/StatementBalanceSheetsUnauditedParenthetical Balance Sheets (unaudited) (Parenthetical) Statements 3 false false R4.htm 00200 - Statement - Statements of Operations (Unaudited) Sheet http://www.passagebio.com/role/StatementStatementsOfOperationsUnaudited Statements of Operations (Unaudited) Statements 4 false false R5.htm 00300 - Statement - Statements of Changes in Convertible Preferred Stock and Stockholders??? Equity (Deficit) Sheet http://www.passagebio.com/role/StatementStatementsOfChangesInConvertiblePreferredStockAndStockholdersEquityDeficit Statements of Changes in Convertible Preferred Stock and Stockholders??? Equity (Deficit) Statements 5 false false R6.htm 00305 - Statement - Statements of Changes in Convertible Preferred Stock and Stockholders??? Equity (Deficit) (Parenthetical) Sheet http://www.passagebio.com/role/StatementStatementsOfChangesInConvertiblePreferredStockAndStockholdersEquityDeficitParenthetical Statements of Changes in Convertible Preferred Stock and Stockholders??? Equity (Deficit) (Parenthetical) Statements 6 false false R7.htm 00400 - Statement - Statements of Cash Flows (Unaudited) Sheet http://www.passagebio.com/role/StatementStatementsOfCashFlowsUnaudited Statements of Cash Flows (Unaudited) Statements 7 false false R8.htm 10101 - Disclosure - Nature of Operations Sheet http://www.passagebio.com/role/DisclosureNatureOfOperations Nature of Operations Notes 8 false false R9.htm 10201 - Disclosure - Risks and Liquidity Sheet http://www.passagebio.com/role/DisclosureRisksAndLiquidity Risks and Liquidity Notes 9 false false R10.htm 10301 - Disclosure - Summary of Significant Accounting Policies Sheet http://www.passagebio.com/role/DisclosureSummaryOfSignificantAccountingPolicies Summary of Significant Accounting Policies Notes 10 false false R11.htm 10401 - Disclosure - Fair Value of Financial Instruments Sheet http://www.passagebio.com/role/DisclosureFairValueOfFinancialInstruments Fair Value of Financial Instruments Notes 11 false false R12.htm 10501 - Disclosure - Accrued Expenses and Other Current Liabilities Sheet http://www.passagebio.com/role/DisclosureAccruedExpensesAndOtherCurrentLiabilities Accrued Expenses and Other Current Liabilities Notes 12 false false R13.htm 10601 - Disclosure - Commitments Sheet http://www.passagebio.com/role/DisclosureCommitments Commitments Notes 13 false false R14.htm 10701 - Disclosure - Convertible Preferred Stock and Common Stock Sheet http://www.passagebio.com/role/DisclosureConvertiblePreferredStockAndCommonStock Convertible Preferred Stock and Common Stock Notes 14 false false R15.htm 10801 - Disclosure - Share???Based Compensation Sheet http://www.passagebio.com/role/DisclosureSharebasedCompensation Share???Based Compensation Notes 15 false false R16.htm 10901 - Disclosure - Related Party Transactions Sheet http://www.passagebio.com/role/DisclosureRelatedPartyTransactions Related Party Transactions Notes 16 false false R17.htm 11001 - Disclosure - Subsequent Events Sheet http://www.passagebio.com/role/DisclosureSubsequentEvents Subsequent Events Notes 17 false false R18.htm 20302 - Disclosure - Summary of Significant Accounting Policies (Policies) Sheet http://www.passagebio.com/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies Summary of Significant Accounting Policies (Policies) Policies http://www.passagebio.com/role/DisclosureSummaryOfSignificantAccountingPolicies 18 false false R19.htm 30303 - Disclosure - Summary of Significant Accounting Policies (Tables) Sheet http://www.passagebio.com/role/DisclosureSummaryOfSignificantAccountingPoliciesTables Summary of Significant Accounting Policies (Tables) Tables http://www.passagebio.com/role/DisclosureSummaryOfSignificantAccountingPolicies 19 false false R20.htm 30403 - Disclosure - Fair Value of Financial Instruments (Tables) Sheet http://www.passagebio.com/role/DisclosureFairValueOfFinancialInstrumentsTables Fair Value of Financial Instruments (Tables) Tables http://www.passagebio.com/role/DisclosureFairValueOfFinancialInstruments 20 false false R21.htm 30503 - Disclosure - Accrued Expenses and Other Current Liabilities (Tables) Sheet http://www.passagebio.com/role/DisclosureAccruedExpensesAndOtherCurrentLiabilitiesTables Accrued Expenses and Other Current Liabilities (Tables) Tables http://www.passagebio.com/role/DisclosureAccruedExpensesAndOtherCurrentLiabilities 21 false false R22.htm 30603 - Disclosure - Commitments (Tables) Sheet http://www.passagebio.com/role/DisclosureCommitmentsTables Commitments (Tables) Tables http://www.passagebio.com/role/DisclosureCommitments 22 false false R23.htm 30803 - Disclosure - Share???Based Compensation (Tables) Sheet http://www.passagebio.com/role/DisclosureSharebasedCompensationTables Share???Based Compensation (Tables) Tables http://www.passagebio.com/role/DisclosureSharebasedCompensation 23 false false R24.htm 40201 - Disclosure - Risks and Liquidity (Details) Sheet http://www.passagebio.com/role/DisclosureRisksAndLiquidityDetails Risks and Liquidity (Details) Details http://www.passagebio.com/role/DisclosureRisksAndLiquidity 24 false false R25.htm 40301 - Disclosure - Summary of Significant Accounting Policies (Details) Sheet http://www.passagebio.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails Summary of Significant Accounting Policies (Details) Details http://www.passagebio.com/role/DisclosureSummaryOfSignificantAccountingPoliciesTables 25 false false R26.htm 40401 - Disclosure - Fair Value of Financial Instruments (Details) Sheet http://www.passagebio.com/role/DisclosureFairValueOfFinancialInstrumentsDetails Fair Value of Financial Instruments (Details) Details http://www.passagebio.com/role/DisclosureFairValueOfFinancialInstrumentsTables 26 false false R27.htm 40501 - Disclosure - Accrued Expenses and Other Current Liabilities (Details) Sheet http://www.passagebio.com/role/DisclosureAccruedExpensesAndOtherCurrentLiabilitiesDetails Accrued Expenses and Other Current Liabilities (Details) Details http://www.passagebio.com/role/DisclosureAccruedExpensesAndOtherCurrentLiabilitiesTables 27 false false R28.htm 40601 - Disclosure - Commitments - Paragon Collaboration Agreement (Details) Sheet http://www.passagebio.com/role/DisclosureCommitmentsParagonCollaborationAgreementDetails Commitments - Paragon Collaboration Agreement (Details) Details 28 false false R29.htm 40602 - Disclosure - Commitments - Operating Lease (Details) Sheet http://www.passagebio.com/role/DisclosureCommitmentsOperatingLeaseDetails Commitments - Operating Lease (Details) Details 29 false false R30.htm 40701 - Disclosure - Convertible Preferred Stock and Common Stock (Details) Sheet http://www.passagebio.com/role/DisclosureConvertiblePreferredStockAndCommonStockDetails Convertible Preferred Stock and Common Stock (Details) Details http://www.passagebio.com/role/DisclosureConvertiblePreferredStockAndCommonStock 30 false false R31.htm 40801 - Disclosure - Share???Based Compensation - Equity Incentive Plan & ESPP (Details) Sheet http://www.passagebio.com/role/DisclosureSharebasedCompensationEquityIncentivePlanEsppDetails Share???Based Compensation - Equity Incentive Plan & ESPP (Details) Details 31 false false R32.htm 40802 - Disclosure - Share???Based Compensation - Share-based compensation expense (Details) Sheet http://www.passagebio.com/role/DisclosureSharebasedCompensationShareBasedCompensationExpenseDetails Share???Based Compensation - Share-based compensation expense (Details) Details 32 false false R33.htm 40803 - Disclosure - Share???Based Compensation - Stock Option Activity (Details) Sheet http://www.passagebio.com/role/DisclosureSharebasedCompensationStockOptionActivityDetails Share???Based Compensation - Stock Option Activity (Details) Details 33 false false R34.htm 40804 - Disclosure - Share???Based Compensation - Assumptions Used in Determining Fair Value & Early exercise of Stock Options (Details) Sheet http://www.passagebio.com/role/DisclosureSharebasedCompensationAssumptionsUsedInDeterminingFairValueEarlyExerciseOfStockOptionsDetails Share???Based Compensation - Assumptions Used in Determining Fair Value & Early exercise of Stock Options (Details) Details 34 false false R35.htm 40805 - Disclosure - Share-Based Compensation - Nonrecourse Promissory Notes with related parties (Details) Notes http://www.passagebio.com/role/DisclosureShareBasedCompensationNonrecoursePromissoryNotesWithRelatedPartiesDetails Share-Based Compensation - Nonrecourse Promissory Notes with related parties (Details) Details 35 false false R36.htm 40901 - Disclosure - Related Party Transactions (Details) Sheet http://www.passagebio.com/role/DisclosureRelatedPartyTransactionsDetails Related Party Transactions (Details) Details http://www.passagebio.com/role/DisclosureRelatedPartyTransactions 36 false false All Reports Book All Reports pasg-20200331.xml pasg-20200331.xsd pasg-20200331_cal.xml pasg-20200331_def.xml pasg-20200331_lab.xml pasg-20200331_pre.xml http://xbrl.sec.gov/dei/2019-01-31 http://fasb.org/us-gaap/2019-01-31 http://fasb.org/srt/2019-01-31 true true