0001564590-21-053565 | 10-Q | XBRL Viewer

Liability Related to Sale of Future Royalties -Schedule of Activity Within Liability Related to Sale of Future Royalties (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2021	Dec. 31, 2020
Liability Related To Sale Of Future Royalties [Line Items]
Liability related to sale of future royalties, beginning balance	$ 193,298
Zolgensma royalties paid to HCR	(33,252)
Non-cash interest expense	19,777
Liability related to sale of future royalties, ending balance	179,823
Liability related to sale of future royalties	(35,508)	$ 18,794
Liability related to sale of future royalties	$ 144,315	$ 174,504

Label	Element	Value
Unbilled Receivables Non Current	rgnx_UnbilledReceivablesNonCurrent	$ 2,730,000
Unbilled Receivables Non Current	rgnx_UnbilledReceivablesNonCurrent	3,267,000
Proceeds From Issuances Of Common Stock Net Of Underwriting Discounts And Commissions	rgnx_ProceedsFromIssuancesOfCommonStockNetOfUnderwritingDiscountsAndCommissions	$ 216,438,000
Additional Proceeds From Acquiring Business	rgnx_AdditionalProceedsFromAcquiringBusiness	$ 600,000
Additional Proceeds From Acquiring Business	rgnx_AdditionalProceedsFromAcquiringBusiness	$ 600,000
Provision For Credit Losses And Other	rgnx_ProvisionForCreditLossesAndOther	5,131,000
Provision For Credit Losses And Other	rgnx_ProvisionForCreditLossesAndOther	7,770,000
Provision For Credit Losses And Other	rgnx_ProvisionForCreditLossesAndOther	5,781,000
Provision For Credit Losses And Other	rgnx_ProvisionForCreditLossesAndOther	7,887,000
Revenue Recognized Performance Obligation	rgnx_RevenueRecognizedPerformanceObligation	30,256,000
Revenue Recognized Performance Obligation	rgnx_RevenueRecognizedPerformanceObligation	98,799,000
Revenue Recognized Performance Obligation	rgnx_RevenueRecognizedPerformanceObligation	70,603,000
Revenue Recognized Performance Obligation	rgnx_RevenueRecognizedPerformanceObligation	125,555,000
Proceeds From Sales Of Marketable Debt Securities	rgnx_ProceedsFromSalesOfMarketableDebtSecurities	2,287,000
Allowance For Credit Losses Current	rgnx_AllowanceForCreditLossesCurrent	13,210,000
Allowance For Credit Losses Current	rgnx_AllowanceForCreditLossesCurrent	7,678,000
Proceeds From Stock Options Exercised Including Unsettled Options	rgnx_ProceedsFromStockOptionsExercisedIncludingUnsettledOptions	3,300,000
Non Cash Additions To Property And Equipment Through Tenant Improvement Allowance	rgnx_NonCashAdditionsToPropertyAndEquipmentThroughTenantImprovementAllowance	2,217,000
Remeasurements Or Impairment Losses On Non Marketable Equity Securities	rgnx_RemeasurementsOrImpairmentLossesOnNonMarketableEquitySecurities	0
Remeasurements Or Impairment Losses On Non Marketable Equity Securities	rgnx_RemeasurementsOrImpairmentLossesOnNonMarketableEquitySecurities	0
Remeasurements Or Impairment Losses On Non Marketable Equity Securities	rgnx_RemeasurementsOrImpairmentLossesOnNonMarketableEquitySecurities	0
Remeasurements Or Impairment Losses On Non Marketable Equity Securities	rgnx_RemeasurementsOrImpairmentLossesOnNonMarketableEquitySecurities	0
Accrued Sublicense Fees And Royalties On Reagent Sales	rgnx_AccruedSublicenseFeesAndRoyaltiesOnReagentSales	15,869,000
Accrued Sublicense Fees And Royalties On Reagent Sales	rgnx_AccruedSublicenseFeesAndRoyaltiesOnReagentSales	12,160,000
Accrued External General And Administrative Expenses	rgnx_AccruedExternalGeneralAndAdministrativeExpenses	2,974,000
Accrued External General And Administrative Expenses	rgnx_AccruedExternalGeneralAndAdministrativeExpenses	2,865,000
Increase Decrease In Operating Lease Liabilities	rgnx_IncreaseDecreaseInOperatingLeaseLiabilities	10,849,000
Increase Decrease In Operating Lease Liabilities	rgnx_IncreaseDecreaseInOperatingLeaseLiabilities	(2,222,000)
Payments Of Transaction Costs For Sale Of Future Loyalties	rgnx_PaymentsOfTransactionCostsForSaleOfFutureLoyalties	$ 265,000
Proceeds From Acquiring Business	rgnx_ProceedsFromAcquiringBusiness	$ 4,800,000
Proceeds From Acquiring Business	rgnx_ProceedsFromAcquiringBusiness	$ 5,600,000
Repayments Under Liability Related To Sale Of Future Royalties	rgnx_RepaymentsUnderLiabilityRelatedToSaleOfFutureRoyalties	33,252,000
Accrued Purchases Of Property And Equipment	rgnx_AccruedPurchasesOfPropertyAndEquipment	8,303,000
Accrued Purchases Of Property And Equipment	rgnx_AccruedPurchasesOfPropertyAndEquipment	7,853,000
Transaction Costs Associated With Stock Issuance	rgnx_TransactionCostsAssociatedWithStockIssuance	14,194,000
Other Comprehensive Income Realized Holding Gain Loss On Securities Arising During Period Before Tax	rgnx_OtherComprehensiveIncomeRealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	(30,000)
Other Comprehensive Income Realized Holding Gain Loss On Securities Arising During Period Before Tax	rgnx_OtherComprehensiveIncomeRealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	(7,000)
Other Comprehensive Income Realized Holding Gain Loss On Securities Arising During Period Before Tax	rgnx_OtherComprehensiveIncomeRealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	(50,000)
Non Marketable Equity Securities Carrying Value	rgnx_NonMarketableEquitySecuritiesCarryingValue	0
Non Marketable Equity Securities Carrying Value	rgnx_NonMarketableEquitySecuritiesCarryingValue	1,100,000
Imputed Interest Income From Licensing	rgnx_ImputedInterestIncomeFromLicensing	341,000
Imputed Interest Income From Licensing	rgnx_ImputedInterestIncomeFromLicensing	2,033,000
Proceeds Due To Company From Sales Of Non Marketable Equity Securities	rgnx_ProceedsDueToCompanyFromSalesOfNonMarketableEquitySecurities	646,000
Increase Decrease In Operating Lease Right Of Use Assets	rgnx_IncreaseDecreaseInOperatingLeaseRightOfUseAssets	(3,780,000)
Increase Decrease In Operating Lease Right Of Use Assets	rgnx_IncreaseDecreaseInOperatingLeaseRightOfUseAssets	(1,986,000)
Accrued Expenses And Other Current Liabilities	rgnx_AccruedExpensesAndOtherCurrentLiabilities	49,694,000
Accrued Expenses And Other Current Liabilities	rgnx_AccruedExpensesAndOtherCurrentLiabilities	49,082,000
Non Cash Interest Expense	rgnx_NonCashInterestExpense	19,777,000
Available For Sale Debt Securities Remaining Maturities Greater Than Three Years	rgnx_AvailableForSaleDebtSecuritiesRemainingMaturitiesGreaterThanThreeYears	0
Available For Sale Debt Securities Remaining Maturities Greater Than Three Years	rgnx_AvailableForSaleDebtSecuritiesRemainingMaturitiesGreaterThanThreeYears	0
Accrued External Research And Development Expenses	rgnx_AccruedExternalResearchAndDevelopmentExpenses	8,069,000
Accrued External Research And Development Expenses	rgnx_AccruedExternalResearchAndDevelopmentExpenses	$ 9,738,000

License and Royalty Revenue - Additional Information (Detail)			3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended
	May 31, 2020 USD ($)	Apr. 01, 2020 USD ($)	Sep. 30, 2021 USD ($) ProductCandidate	Sep. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Sep. 30, 2021 USD ($) ProductCandidate	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)	Jul. 31, 2021 USD ($)
License Revenue [Line Items]
Number of development partnered product candidates \| ProductCandidate			20			20
Number of commercial product candidates \| ProductCandidate			1			1
Milestone payment upon commencement of clinical trials in humans						$ 23,300,000
Milestone payment upon submission of regulatory approval filings						21,000,000.0
Milestone payment upon approval of commercial products by regulatory agencies						93,500,000
Milestone payment upon achievement of specified sales targets for licensed products						1,000.0
Aggregate milestone payment for all the targets						80,000,000.0
Milestone Payments						80,000,000.0
License fee	$ 20,000,000.0	$ 8,000,000.0			$ 28,000,000.0
Up-front and annual fees		$ 20,000,000.0
Interest income from licensing			$ 5,000	$ 6,000		2,100,000	$ 20,000	$ 2,100,000
Accrued interest receivable									$ 3,500,000
Upfront License Fee Paid						370,000.0
Milestone Fee Payments Upon Achievement of Various Development and Commercialization						$ 782,500

Liability Related to Sale of Future Royalties - Additional Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021 USD ($)
Liability Related To Sale Of Future Royalties [Line Items]
Purchase Agreement	$ 200,000
Royalty Payment Cap Amount	300,000
Repurchase of call option amount	300,000
Repurchase of call option amount, before exercised	1,000
Proceeds from sale of future royalties	196,000
Deferred Transaction Cost	3,500
Non-cash interest expense	$ 19,777

License and Royalty Revenue - Summary of Changes in Balances of Receivables, Contract Assets and Deferred Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accounts receivable, net, current and non-current:
Additions	$ 30,385	$ 100,243	$ 71,544	$ 137,220
Deductions	(28,840)	(21,057)	(69,063)	(53,843)
Contract assets:
Additions	407		1,109	350
Deductions			(350)
Deferred revenue, current and non-current:
Additions				1,124
Deductions	$ (99)	$ (113)	$ (306)	$ (113)