License and Collaboration Agreements - Schedule Of License and Royalty Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
License Revenue [Line Items]
Other license and royalty revenue	$ 1,012	$ 4,263	$ 4,024	$ 4,942
Total license and royalty revenue	19,977	32,649	39,115	54,867
Zolgensma Royalties [Member]
License Revenue [Line Items]
Zolgensma royalties	$ 18,965	$ 28,386	$ 35,091	$ 49,925