License and Collaboration Agreements - Schedule Of License Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
License Revenue [Line Items]
Interest income from licensing	$ 70	$ 94
Novartis Gene Therapies [Member]
License Revenue [Line Items]
Total license and royalty revenue	16,125	21,539
Interest income from licensing	8	5
Zolgensma Royalties [Member]
License Revenue [Line Items]
Total license and royalty revenue	$ 16,125	$ 21,539