Balance Sheet Components - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Mar. 31, 2023
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 113,260	$ 113,924
Less: accumulated depreciation and amortization	(82,990)	(75,316)
Less: accumulated depreciation and amortization	30,270	38,608
Computer and software
Property Plant And Equipment [Line Items]
Property and equipment, gross	9,580	10,376
Laboratory equipment and software
Property Plant And Equipment [Line Items]
Property and equipment, gross	52,803	52,785
Furniture and office equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	8,963	8,946
Leasehold improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	41,061	40,964
Capitalized asset retirement obligations
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 853	$ 853