Liability Related to Sale of Future Royalties -Schedule of Activity Within Liability Related to Sale of Future Royalties (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Liability Related To Sale Of Future Royalties [Line Items]
Current portion of liability related to sale of future royalties	$ (48,963)	$ (48,601)
Non-current portion of liability related to sale of future royalties	67,377	$ 89,005
Royalty Agreements
Liability Related To Sale Of Future Royalties [Line Items]
Balance at December 31, 2022	137,606
Zolgensma royalties paid to HCR	(24,694)
Interest expense recognized	3,428
Balance at June 30, 2023	116,340
Current portion of liability related to sale of future royalties	(48,963)
Non-current portion of liability related to sale of future royalties	$ 67,377