3.21.2 html 154 273 1 false 38 0 false 5 false false R1.htm 100000 - Document - Document and Entity Information Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DocumentDocumentAndEntityInformation Document and Entity Information Cover 1 false false R2.htm 100010 - Statement - Condensed Balance Sheets Sheet http://www.cabalettabio.com/20210630/taxonomy/role/StatementCondensedBalanceSheets Condensed Balance Sheets Statements 2 false false R3.htm 100020 - Statement - Condensed Balance Sheets (Parenthetical) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/StatementCondensedBalanceSheetsParenthetical Condensed Balance Sheets (Parenthetical) Statements 3 false false R4.htm 100030 - Statement - Condensed Statements of Operations and Comprehensive Loss (Unaudited) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/StatementCondensedStatementsOfOperationsAndComprehensiveLossUnaudited Condensed Statements of Operations and Comprehensive Loss (Unaudited) Statements 4 false false R5.htm 100040 - Statement - Condensed Statements of Stockholders' Equity (Unaudited) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/StatementCondensedStatementsOfStockholdersEquityUnaudited Condensed Statements of Stockholders' Equity (Unaudited) Statements 5 false false R6.htm 100050 - Statement - Condensed Statements of Stockholders' Equity (Unaudited) (Parenthetical) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/StatementCondensedStatementsOfStockholdersEquityUnauditedParenthetical Condensed Statements of Stockholders' Equity (Unaudited) (Parenthetical) Statements 6 false false R7.htm 100060 - Statement - Condensed Statements of Cash Flows (Unaudited) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/StatementCondensedStatementsOfCashFlowsUnaudited Condensed Statements of Cash Flows (Unaudited) Statements 7 false false R8.htm 100070 - Disclosure - Basis of Presentation Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureBasisOfPresentation Basis of Presentation Notes 8 false false R9.htm 100080 - Disclosure - Summary of Significant Accounting Policies Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies Summary of Significant Accounting Policies Notes 9 false false R10.htm 100090 - Disclosure - Fair Value Measurements Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureFairValueMeasurements Fair Value Measurements Notes 10 false false R11.htm 100100 - Disclosure - Accrued and Other Current Liabilities Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureAccruedAndOtherCurrentLiabilities Accrued and Other Current Liabilities Notes 11 false false R12.htm 100110 - Disclosure - Collaborations, Licensing Agreements and other Agreements Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureCollaborationsLicensingAgreementsAndOtherAgreements Collaborations, Licensing Agreements and other Agreements Notes 12 false false R13.htm 100120 - Disclosure - Commitments and Contingencies Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureCommitmentsAndContingencies Commitments and Contingencies Notes 13 false false R14.htm 100130 - Disclosure - Common Stock Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureCommonStock Common Stock Notes 14 false false R15.htm 100140 - Disclosure - Income Taxes Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureIncomeTaxes Income Taxes Notes 15 false false R16.htm 100150 - Disclosure - Net Loss Per Share Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureNetLossPerShare Net Loss Per Share Notes 16 false false R17.htm 100160 - Disclosure - Subsequent Event Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureSubsequentEvent Subsequent Event Notes 17 false false R18.htm 100170 - Disclosure - Summary of Significant Accounting Policies (Policies) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies Summary of Significant Accounting Policies (Policies) Policies http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureSummaryOfSignificantAccountingPolicies 18 false false R19.htm 100180 - Disclosure - Fair Value Measurements (Tables) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureFairValueMeasurementsTables Fair Value Measurements (Tables) Tables http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureFairValueMeasurements 19 false false R20.htm 100190 - Disclosure - Accrued and Other Current Liabilities (Tables) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureAccruedAndOtherCurrentLiabilitiesTables Accrued and Other Current Liabilities (Tables) Tables http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureAccruedAndOtherCurrentLiabilities 20 false false R21.htm 100200 - Disclosure - Commitments and Contingencies (Tables) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureCommitmentsAndContingenciesTables Commitments and Contingencies (Tables) Tables http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureCommitmentsAndContingencies 21 false false R22.htm 100210 - Disclosure - Common Stock (Tables) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureCommonStockTables Common Stock (Tables) Tables http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureCommonStock 22 false false R23.htm 100220 - Disclosure - Net Loss Per Share (Tables) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureNetLossPerShareTables Net Loss Per Share (Tables) Tables http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureNetLossPerShare 23 false false R24.htm 100230 - Disclosure - Basis of Presentation - Additional Information (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureBasisOfPresentationAdditionalInformationDetails Basis of Presentation - Additional Information (Details) Details 24 false false R25.htm 100240 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureSummaryOfSignificantAccountingPoliciesAdditionalInformationDetails Summary of Significant Accounting Policies - Additional Information (Details) Details 25 false false R26.htm 100250 - Disclosure - Fair Value Measurements - Financial Assets Measured at Fair Value on Recurring Basis (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureFairValueMeasurementsFinancialAssetsMeasuredAtFairValueOnRecurringBasisDetails Fair Value Measurements - Financial Assets Measured at Fair Value on Recurring Basis (Details) Details 26 false false R27.htm 100260 - Disclosure - Fair Value Measurements - Additional Information (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureFairValueMeasurementsAdditionalInformationDetails Fair Value Measurements - Additional Information (Details) Details 27 false false R28.htm 100270 - Disclosure - Fair Value Measurements - Schedule of Debt Securities Classified as Available-for-Sale Investments (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfDebtSecuritiesClassifiedAsAvailableForSaleInvestmentsDetails Fair Value Measurements - Schedule of Debt Securities Classified as Available-for-Sale Investments (Details) Details 28 false false R29.htm 100280 - Disclosure - Accrued and Other Current Liabilities - Schedule of Accrued and Other Current Liabilities (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureAccruedAndOtherCurrentLiabilitiesScheduleOfAccruedAndOtherCurrentLiabilitiesDetails Accrued and Other Current Liabilities - Schedule of Accrued and Other Current Liabilities (Details) Details 29 false false R30.htm 100290 - Disclosure - Collaborations, Licensing Agreements and other Agreements - Additional Information (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureCollaborationsLicensingAgreementsAndOtherAgreementsAdditionalInformationDetails Collaborations, Licensing Agreements and other Agreements - Additional Information (Details) Details 30 false false R31.htm 100300 - Disclosure - Commitments and Contingencies - Additional Information (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureCommitmentsAndContingenciesAdditionalInformationDetails Commitments and Contingencies - Additional Information (Details) Details 31 false false R32.htm 100310 - Disclosure - Commitments and Contingencies - Schedule of Future Minimum Payments for Operating Leases (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureCommitmentsAndContingenciesScheduleOfFutureMinimumPaymentsForOperatingLeasesDetails Commitments and Contingencies - Schedule of Future Minimum Payments for Operating Leases (Details) Details 32 false false R33.htm 100320 - Disclosure - Common Stock - Additional Information (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureCommonStockAdditionalInformationDetails Common Stock - Additional Information (Details) Details 33 false false R34.htm 100330 - Disclosure - Common Stock - Summary of Stock Option Activity (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureCommonStockSummaryOfStockOptionActivityDetails Common Stock - Summary of Stock Option Activity (Details) Details 34 false false R35.htm 100340 - Disclosure - Common Stock - Schedule of Assumptions Used to Estimate Fair Value of Stock Options (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureCommonStockScheduleOfAssumptionsUsedToEstimateFairValueOfStockOptionsDetails Common Stock - Schedule of Assumptions Used to Estimate Fair Value of Stock Options (Details) Details 35 false false R36.htm 100350 - Disclosure - Common Stock - Summary of Stock-Based Compensation (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureCommonStockSummaryOfStockBasedCompensationDetails Common Stock - Summary of Stock-Based Compensation (Details) Details 36 false false R37.htm 100360 - Disclosure - Income Taxes - Additional Information (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetails Income Taxes - Additional Information (Details) Details 37 false false R38.htm 100370 - Disclosure - Net Loss Per Share - Schedule of Basic and Diluted Earnings Per Share (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureNetLossPerShareScheduleOfBasicAndDilutedEarningsPerShareDetails Net Loss Per Share - Schedule of Basic and Diluted Earnings Per Share (Details) Details 38 false false R39.htm 100380 - Disclosure - Net Loss Per Share - Schedule of Antidilutive Shares Excluded from Calculation of Diluted Net Loss Per Share (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureNetLossPerShareScheduleOfAntidilutiveSharesExcludedFromCalculationOfDilutedNetLossPerShareDetails Net Loss Per Share - Schedule of Antidilutive Shares Excluded from Calculation of Diluted Net Loss Per Share (Details) Details 39 false false R40.htm 100390 - Disclosure - Subsequent Event - Additional Information (Details) Sheet http://www.cabalettabio.com/20210630/taxonomy/role/DisclosureSubsequentEventAdditionalInformationDetails Subsequent Event - Additional Information (Details) Details 40 false false All Reports Book All Reports caba-10q_20210630.htm caba-20210630.xsd caba-20210630_cal.xml caba-20210630_def.xml caba-20210630_lab.xml caba-20210630_pre.xml caba-ex311_8.htm caba-ex312_10.htm caba-ex321_7.htm caba-ex322_9.htm http://fasb.org/srt/2020-01-31 http://xbrl.sec.gov/dei/2020-01-31 http://fasb.org/us-gaap/2020-01-31 true true