Stockholders' Equity - Schedule of Common Stock Reserved for Issuance (Detail) - shares	Dec. 31, 2023	Mar. 31, 2023
Class of Stock [Line Items]
Outstanding stock options (in shares)	73,646,882	68,050,752
Total shares of common stock reserved (in shares)	217,531,118	163,884,802
2021 Incentive Equity Plan
Class of Stock [Line Items]
Remaining shares available for future issuance under Amended and Restated 2021 Incentive Equity Plan (in shares)	90,697,138	55,922,182
Employee Stock Purchase Plan
Class of Stock [Line Items]
Remaining shares available for future issuance under Employee Stock Purchase Plan (in shares)	11,839,766	13,349,302
Unvested restricted stock units
Class of Stock [Line Items]
Outstanding restricted stock units (in shares)	41,347,332	26,562,566