Collaborations - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Mar. 31, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue	$ 55,204	$ 51,804	$ 114,443	$ 99,861
Deferred Revenue Current	67,681		67,681		$ 71,255
Cost of Revenue	27,276	27,209	55,818	52,773
Accounts Payable and Other Accrued Liabilities, Current	29,541		29,541		31,953
G S K
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue	10,000	9,800	21,200	21,700
Deferred Revenue Current	33,900		33,900		30,100
Deferred Revenue, Noncurrent	0		0		0
Receivables, Net, Current	25,000		25,000		0
Research and development expense	5,900	4,600	11,900	6,400
Cost of Revenue			300
Cost of revenue expense related party	(200)	$ (1,100)		$ (700)
Accounts Payable and Other Accrued Liabilities, Current	$ 12,600		$ 12,600		$ 11,500