Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Tax Contingency [Line Items]
Valuation allowance	$ 78,071	$ 47,076
Impact on effective tax rate	102,500
Accrued interest or penalties associated with uncertain tax positions	1,200	$ 0
Accrued interest and penalties	2,000
United States [Member]
Income Tax Contingency [Line Items]
Operating loss carryforwards	$ 854,700
Operating loss carryforwards expiration beginning year	2023
Tax years subject to examination	2019 and thereafter
United States [Member] | Research & Development [Member]
Income Tax Contingency [Line Items]
Tax credit carryforward amount	$ 242,900
United States [Member] | Research & Development [Member] | Earliest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax credit carryforwards expiration beginning year	2026
State [Member]
Income Tax Contingency [Line Items]
Operating loss carryforwards	$ 546,500
Operating loss carryforwards expiration beginning year	2023
Tax years subject to examination	2019 and thereafter
State [Member] | Research & Development [Member]
Income Tax Contingency [Line Items]
Tax credit carryforward amount	$ 192,800
State [Member] | Research & Development [Member] | Earliest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax credit carryforwards expiration beginning year	2023
Foreign [Member]
Income Tax Contingency [Line Items]
Tax years subject to examination	2018 and thereafter