3.22.1 html 182 303 1 false 57 0 false 7 false false R1.htm 0001001 - Document - Cover Page Sheet http://www.selectabio.com/role/CoverPage Cover Page Cover 1 false false R2.htm 1001002 - Statement - Consolidated Balance Sheets Sheet http://www.selectabio.com/role/ConsolidatedBalanceSheets Consolidated Balance Sheets Statements 2 false false R3.htm 1002003 - Statement - Consolidated Balance Sheets (Parenthetical) Sheet http://www.selectabio.com/role/ConsolidatedBalanceSheetsParenthetical Consolidated Balance Sheets (Parenthetical) Statements 3 false false R4.htm 1003004 - Statement - Consolidated Statements of Operations and Comprehensive Income (Loss) Sheet http://www.selectabio.com/role/ConsolidatedStatementsofOperationsandComprehensiveIncomeLoss Consolidated Statements of Operations and Comprehensive Income (Loss) Statements 4 false false R5.htm 1004005 - Statement - Consolidated Statements of Changes in Stockholders??? (Deficit) Equity Sheet http://www.selectabio.com/role/ConsolidatedStatementsofChangesinStockholdersDeficitEquity Consolidated Statements of Changes in Stockholders??? (Deficit) Equity Statements 5 false false R6.htm 1005006 - Statement - Consolidated Statements of Cash Flows Sheet http://www.selectabio.com/role/ConsolidatedStatementsofCashFlows Consolidated Statements of Cash Flows Statements 6 false false R7.htm 2101101 - Disclosure - Description of the Business Sheet http://www.selectabio.com/role/DescriptionoftheBusiness Description of the Business Notes 7 false false R8.htm 2103102 - Disclosure - Summary of Significant Accounting Policies Sheet http://www.selectabio.com/role/SummaryofSignificantAccountingPolicies Summary of Significant Accounting Policies Notes 8 false false R9.htm 2105103 - Disclosure - Marketable Securities and Investments Sheet http://www.selectabio.com/role/MarketableSecuritiesandInvestments Marketable Securities and Investments Notes 9 false false R10.htm 2109104 - Disclosure - Net Income (Loss) Per Share Sheet http://www.selectabio.com/role/NetIncomeLossPerShare Net Income (Loss) Per Share Notes 10 false false R11.htm 2113105 - Disclosure - Fair Value Measurements Sheet http://www.selectabio.com/role/FairValueMeasurements Fair Value Measurements Notes 11 false false R12.htm 2120106 - Disclosure - Property and Equipment Sheet http://www.selectabio.com/role/PropertyandEquipment Property and Equipment Notes 12 false false R13.htm 2124107 - Disclosure - Accrued Expenses Sheet http://www.selectabio.com/role/AccruedExpenses Accrued Expenses Notes 13 false false R14.htm 2128108 - Disclosure - Leases Sheet http://www.selectabio.com/role/Leases Leases Notes 14 false false R15.htm 2134109 - Disclosure - Debt Sheet http://www.selectabio.com/role/Debt Debt Notes 15 false false R16.htm 2139110 - Disclosure - Equity Sheet http://www.selectabio.com/role/Equity Equity Notes 16 false false R17.htm 2144111 - Disclosure - Stock Incentive Plans Sheet http://www.selectabio.com/role/StockIncentivePlans Stock Incentive Plans Notes 17 false false R18.htm 2152112 - Disclosure - Revenue Arrangements Sheet http://www.selectabio.com/role/RevenueArrangements Revenue Arrangements Notes 18 false false R19.htm 2156113 - Disclosure - Related-party Transactions Sheet http://www.selectabio.com/role/RelatedpartyTransactions Related-party Transactions Notes 19 false false R20.htm 2158114 - Disclosure - Collaboration and License Agreements Sheet http://www.selectabio.com/role/CollaborationandLicenseAgreements Collaboration and License Agreements Notes 20 false false R21.htm 2164115 - Disclosure - Income Taxes Sheet http://www.selectabio.com/role/IncomeTaxes Income Taxes Notes 21 false false R22.htm 2166116 - Disclosure - Defined Contribution Plan Sheet http://www.selectabio.com/role/DefinedContributionPlan Defined Contribution Plan Notes 22 false false R23.htm 2168117 - Disclosure - Commitments and Contingencies Sheet http://www.selectabio.com/role/CommitmentsandContingencies Commitments and Contingencies Notes 23 false false R24.htm 2170118 - Disclosure - Subsequent Events Sheet http://www.selectabio.com/role/SubsequentEvents Subsequent Events Notes 24 false false R25.htm 2204201 - Disclosure - Summary of Significant Accounting Policies (Policies) Sheet http://www.selectabio.com/role/SummaryofSignificantAccountingPoliciesPolicies Summary of Significant Accounting Policies (Policies) Policies http://www.selectabio.com/role/SummaryofSignificantAccountingPolicies 25 false false R26.htm 2306301 - Disclosure - Marketable Securities and Investments (Tables) Sheet http://www.selectabio.com/role/MarketableSecuritiesandInvestmentsTables Marketable Securities and Investments (Tables) Tables http://www.selectabio.com/role/MarketableSecuritiesandInvestments 26 false false R27.htm 2310302 - Disclosure - Net Income (Loss) Per Share (Tables) Sheet http://www.selectabio.com/role/NetIncomeLossPerShareTables Net Income (Loss) Per Share (Tables) Tables http://www.selectabio.com/role/NetIncomeLossPerShare 27 false false R28.htm 2314303 - Disclosure - Fair Value Measurements (Tables) Sheet http://www.selectabio.com/role/FairValueMeasurementsTables Fair Value Measurements (Tables) Tables http://www.selectabio.com/role/FairValueMeasurements 28 false false R29.htm 2321304 - Disclosure - Property and Equipment (Tables) Sheet http://www.selectabio.com/role/PropertyandEquipmentTables Property and Equipment (Tables) Tables http://www.selectabio.com/role/PropertyandEquipment 29 false false R30.htm 2325305 - Disclosure - Accrued Expenses (Tables) Sheet http://www.selectabio.com/role/AccruedExpensesTables Accrued Expenses (Tables) Tables http://www.selectabio.com/role/AccruedExpenses 30 false false R31.htm 2329306 - Disclosure - Leases (Tables) Sheet http://www.selectabio.com/role/LeasesTables Leases (Tables) Tables http://www.selectabio.com/role/Leases 31 false false R32.htm 2335307 - Disclosure - Debt (Tables) Sheet http://www.selectabio.com/role/DebtTables Debt (Tables) Tables http://www.selectabio.com/role/Debt 32 false false R33.htm 2340308 - Disclosure - Equity (Tables) Sheet http://www.selectabio.com/role/EquityTables Equity (Tables) Tables http://www.selectabio.com/role/Equity 33 false false R34.htm 2345309 - Disclosure - Stock Incentive Plans (Tables) Sheet http://www.selectabio.com/role/StockIncentivePlansTables Stock Incentive Plans (Tables) Tables http://www.selectabio.com/role/StockIncentivePlans 34 false false R35.htm 2353310 - Disclosure - Revenue Arrangements (Tables) Sheet http://www.selectabio.com/role/RevenueArrangementsTables Revenue Arrangements (Tables) Tables http://www.selectabio.com/role/RevenueArrangements 35 false false R36.htm 2402401 - Disclosure - Description of the Business (Details) Sheet http://www.selectabio.com/role/DescriptionoftheBusinessDetails Description of the Business (Details) Details http://www.selectabio.com/role/DescriptionoftheBusiness 36 false false R37.htm 2407402 - Disclosure - Marketable Securities and Investments - Summary of Available-for-Sale Marketable Securities (Details) Sheet http://www.selectabio.com/role/MarketableSecuritiesandInvestmentsSummaryofAvailableforSaleMarketableSecuritiesDetails Marketable Securities and Investments - Summary of Available-for-Sale Marketable Securities (Details) Details 37 false false R38.htm 2408403 - Disclosure - Marketable Securities and Investments - Narrative (Details) Sheet http://www.selectabio.com/role/MarketableSecuritiesandInvestmentsNarrativeDetails Marketable Securities and Investments - Narrative (Details) Details 38 false false R39.htm 2411404 - Disclosure - Net Income (Loss) Per Share- Computation of Basic and Diluted Net Income (Loss) Per Share (Details) Sheet http://www.selectabio.com/role/NetIncomeLossPerShareComputationofBasicandDilutedNetIncomeLossPerShareDetails Net Income (Loss) Per Share- Computation of Basic and Diluted Net Income (Loss) Per Share (Details) Details http://www.selectabio.com/role/NetIncomeLossPerShareTables 39 false false R40.htm 2412405 - Disclosure - Net Income (Loss) Per Share - Schedule of Potential Common Shares Issuable Upon Conversion of Warrants (Details) Sheet http://www.selectabio.com/role/NetIncomeLossPerShareScheduleofPotentialCommonSharesIssuableUponConversionofWarrantsDetails Net Income (Loss) Per Share - Schedule of Potential Common Shares Issuable Upon Conversion of Warrants (Details) Details http://www.selectabio.com/role/NetIncomeLossPerShareTables 40 false false R41.htm 2415406 - Disclosure - Fair Value Measurements - Summary of Assets Measured at Fair Value on a Recurring Basis (Details) Sheet http://www.selectabio.com/role/FairValueMeasurementsSummaryofAssetsMeasuredatFairValueonaRecurringBasisDetails Fair Value Measurements - Summary of Assets Measured at Fair Value on a Recurring Basis (Details) Details 41 false false R42.htm 2416407 - Disclosure - Fair Value Measurements - Narrative (Details) Sheet http://www.selectabio.com/role/FairValueMeasurementsNarrativeDetails Fair Value Measurements - Narrative (Details) Details 42 false false R43.htm 2417408 - Disclosure - Fair Value Measurements - Schedule of Cash and Cash Equivalents (Details) Sheet http://www.selectabio.com/role/FairValueMeasurementsScheduleofCashandCashEquivalentsDetails Fair Value Measurements - Schedule of Cash and Cash Equivalents (Details) Details 43 false false R44.htm 2418409 - Disclosure - Fair Value Measurements - Assumptions used to record the fair value of the warrants (Details) Sheet http://www.selectabio.com/role/FairValueMeasurementsAssumptionsusedtorecordthefairvalueofthewarrantsDetails Fair Value Measurements - Assumptions used to record the fair value of the warrants (Details) Details 44 false false R45.htm 2419410 - Disclosure - Fair Value Measurements - Change in the warrant liabilities (Details) Sheet http://www.selectabio.com/role/FairValueMeasurementsChangeinthewarrantliabilitiesDetails Fair Value Measurements - Change in the warrant liabilities (Details) Details 45 false false R46.htm 2422411 - Disclosure - Property and Equipment - Schedule of Property and Equipment (Details) Sheet http://www.selectabio.com/role/PropertyandEquipmentScheduleofPropertyandEquipmentDetails Property and Equipment - Schedule of Property and Equipment (Details) Details 46 false false R47.htm 2423412 - Disclosure - Property and Equipment - Narrative (Details) Sheet http://www.selectabio.com/role/PropertyandEquipmentNarrativeDetails Property and Equipment - Narrative (Details) Details 47 false false R48.htm 2426413 - Disclosure - Accrued Expenses (Details) Sheet http://www.selectabio.com/role/AccruedExpensesDetails Accrued Expenses (Details) Details http://www.selectabio.com/role/AccruedExpensesTables 48 false false R49.htm 2427414 - Disclosure - Accrued Expenses - Narrative (Details) Sheet http://www.selectabio.com/role/AccruedExpensesNarrativeDetails Accrued Expenses - Narrative (Details) Details 49 false false R50.htm 2430415 - Disclosure - Leases - Components of lease costs (Details) Sheet http://www.selectabio.com/role/LeasesComponentsofleasecostsDetails Leases - Components of lease costs (Details) Details 50 false false R51.htm 2431416 - Disclosure - Leases - Operating Lease, Liability, Maturity (Details) Sheet http://www.selectabio.com/role/LeasesOperatingLeaseLiabilityMaturityDetails Leases - Operating Lease, Liability, Maturity (Details) Details 51 false false R52.htm 2432417 - Disclosure - Leases - Other Information (Details) Sheet http://www.selectabio.com/role/LeasesOtherInformationDetails Leases - Other Information (Details) Details 52 false false R53.htm 2433418 - Disclosure - Leases - Lease Term and Discount Rate (Details) Sheet http://www.selectabio.com/role/LeasesLeaseTermandDiscountRateDetails Leases - Lease Term and Discount Rate (Details) Details 53 false false R54.htm 2436419 - Disclosure - Debt - Term Loans (Narrative) (Details) Sheet http://www.selectabio.com/role/DebtTermLoansNarrativeDetails Debt - Term Loans (Narrative) (Details) Details 54 false false R55.htm 2437420 - Disclosure - Debt - Term Loan And Unamortized Debt Discount Balances (Details) Sheet http://www.selectabio.com/role/DebtTermLoanAndUnamortizedDebtDiscountBalancesDetails Debt - Term Loan And Unamortized Debt Discount Balances (Details) Details 55 false false R56.htm 2438421 - Disclosure - Debt - Schedule of Future Minimum Payments on the Term Loans (Details) Sheet http://www.selectabio.com/role/DebtScheduleofFutureMinimumPaymentsontheTermLoansDetails Debt - Schedule of Future Minimum Payments on the Term Loans (Details) Details 56 false false R57.htm 2441422 - Disclosure - Equity - Narrative (Details) Sheet http://www.selectabio.com/role/EquityNarrativeDetails Equity - Narrative (Details) Details 57 false false R58.htm 2442423 - Disclosure - Equity - Warranty Activity (Details) Sheet http://www.selectabio.com/role/EquityWarrantyActivityDetails Equity - Warranty Activity (Details) Details 58 false false R59.htm 2443424 - Disclosure - Equity - Schedule of Authorized Shares of Common Stock for Future Issuance (Details) Sheet http://www.selectabio.com/role/EquityScheduleofAuthorizedSharesofCommonStockforFutureIssuanceDetails Equity - Schedule of Authorized Shares of Common Stock for Future Issuance (Details) Details 59 false false R60.htm 2446425 - Disclosure - Stock Incentive Plans - Narrative (Details) Sheet http://www.selectabio.com/role/StockIncentivePlansNarrativeDetails Stock Incentive Plans - Narrative (Details) Details 60 false false R61.htm 2447426 - Disclosure - Stock Incentive Plans - Schedule of Stock-Based Compensation Expense Related to Stock Options and Restricted Common Stock (Details) Sheet http://www.selectabio.com/role/StockIncentivePlansScheduleofStockBasedCompensationExpenseRelatedtoStockOptionsandRestrictedCommonStockDetails Stock Incentive Plans - Schedule of Stock-Based Compensation Expense Related to Stock Options and Restricted Common Stock (Details) Details 61 false false R62.htm 2448427 - Disclosure - Stock Incentive Plans - Schedule of Assumptions (Details) Sheet http://www.selectabio.com/role/StockIncentivePlansScheduleofAssumptionsDetails Stock Incentive Plans - Schedule of Assumptions (Details) Details 62 false false R63.htm 2449428 - Disclosure - Stock Incentive Plans - Summary of Options Activity (Details) Sheet http://www.selectabio.com/role/StockIncentivePlansSummaryofOptionsActivityDetails Stock Incentive Plans - Summary of Options Activity (Details) Details 63 false false R64.htm 2450429 - Disclosure - Stock Incentive Plans - Restricted Stock Units (Details) Sheet http://www.selectabio.com/role/StockIncentivePlansRestrictedStockUnitsDetails Stock Incentive Plans - Restricted Stock Units (Details) Details 64 false false R65.htm 2451430 - Disclosure - Stock Incentive Plans - Employee Stock Purchase Plan (Narrative) (Details) Sheet http://www.selectabio.com/role/StockIncentivePlansEmployeeStockPurchasePlanNarrativeDetails Stock Incentive Plans - Employee Stock Purchase Plan (Narrative) (Details) Details 65 false false R66.htm 2454431 - Disclosure - Revenue Arrangements - Narrative (Details) Sheet http://www.selectabio.com/role/RevenueArrangementsNarrativeDetails Revenue Arrangements - Narrative (Details) Details 66 false false R67.htm 2455432 - Disclosure - Revenue Arrangements - Schedule of Changes in Contract Liabilities (Details) Sheet http://www.selectabio.com/role/RevenueArrangementsScheduleofChangesinContractLiabilitiesDetails Revenue Arrangements - Schedule of Changes in Contract Liabilities (Details) Details 67 false false R68.htm 2457433 - Disclosure - Related-party Transactions - Narrative (Details) Sheet http://www.selectabio.com/role/RelatedpartyTransactionsNarrativeDetails Related-party Transactions - Narrative (Details) Details 68 false false R69.htm 2459434 - Disclosure - Collaboration and License Agreements - Ginkgo Agreement (Details) Sheet http://www.selectabio.com/role/CollaborationandLicenseAgreementsGinkgoAgreementDetails Collaboration and License Agreements - Ginkgo Agreement (Details) Details 69 false false R70.htm 2460435 - Disclosure - Collaboration and License Agreements - Cyrus Biotechnology, Inc. (Narrative) (Details) Sheet http://www.selectabio.com/role/CollaborationandLicenseAgreementsCyrusBiotechnologyIncNarrativeDetails Collaboration and License Agreements - Cyrus Biotechnology, Inc. (Narrative) (Details) Details 70 false false R71.htm 2461436 - Disclosure - Collaboration and License Agreements - AskBio (Narrative) (Details) Sheet http://www.selectabio.com/role/CollaborationandLicenseAgreementsAskBioNarrativeDetails Collaboration and License Agreements - AskBio (Narrative) (Details) Details http://www.selectabio.com/role/CollaborationandLicenseAgreements 71 false false R72.htm 2462437 - Disclosure - Collaboration and License Agreements - MIT (Narrative) (Details) Sheet http://www.selectabio.com/role/CollaborationandLicenseAgreementsMITNarrativeDetails Collaboration and License Agreements - MIT (Narrative) (Details) Details http://www.selectabio.com/role/CollaborationandLicenseAgreements 72 false false R73.htm 2463438 - Disclosure - Collaboration and License Agreements - Shenyang Sunshine Pharmaceutical Co., Ltd (Narrative) (Details) Sheet http://www.selectabio.com/role/CollaborationandLicenseAgreementsShenyangSunshinePharmaceuticalCoLtdNarrativeDetails Collaboration and License Agreements - Shenyang Sunshine Pharmaceutical Co., Ltd (Narrative) (Details) Details 73 false false R74.htm 2465439 - Disclosure - Income Taxes - Narrative (Details) Sheet http://www.selectabio.com/role/IncomeTaxesNarrativeDetails Income Taxes - Narrative (Details) Details 74 false false R75.htm 2467440 - Disclosure - Defined Contribution Plan - Narrative (Details) Sheet http://www.selectabio.com/role/DefinedContributionPlanNarrativeDetails Defined Contribution Plan - Narrative (Details) Details 75 false false R76.htm 2469441 - Disclosure - Commitments and Contingencies (Details) Sheet http://www.selectabio.com/role/CommitmentsandContingenciesDetails Commitments and Contingencies (Details) Details http://www.selectabio.com/role/CommitmentsandContingencies 76 false false R77.htm 2471442 - Disclosure - Subsequent Events (Details) Sheet http://www.selectabio.com/role/SubsequentEventsDetails Subsequent Events (Details) Details http://www.selectabio.com/role/SubsequentEvents 77 false false All Reports Book All Reports selb-20220331.htm exhibit311_03312022.htm exhibit312_03312022.htm exhibit321_03312022.htm selb-20220331.xsd selb-20220331_cal.xml selb-20220331_def.xml selb-20220331_lab.xml selb-20220331_pre.xml http://fasb.org/us-gaap/2021-01-31 http://xbrl.sec.gov/dei/2021q4 true true