Stockholders' Equity - Summary of Company's Common Stock Reserved for Future Issuance (Detail) - shares	Dec. 31, 2023	Dec. 31, 2022
Class of Stock [Line Items]
Common shares reserved for future issuance	82,654,698	76,338,628
Stock Options [Member]
Class of Stock [Line Items]
Common shares reserved for future issuance	21,664,377	24,716,270
Warrants To Acquire Common Stock [Member]
Class of Stock [Line Items]
Common shares reserved for future issuance	8,301,202	8,301,202
Public Warrants Outstanding [Member]
Class of Stock [Line Items]
Common shares reserved for future issuance	5,228,253	5,231,486
Restricted Stock Units Outstanding [Member]
Class of Stock [Line Items]
Common shares reserved for future issuance	15,107,535	9,320,045
Performance-Based Restricted Stock Units [Member]
Class of Stock [Line Items]
Common shares reserved for future issuance	12,923,499	0
Shares Available for Grant under the 2021 Equity Incentive Plan [Member]
Class of Stock [Line Items]
Common shares reserved for future issuance	14,075,832	23,415,625
Shares Available for Issuance under the Employee Stock Purchase Plan [Member]
Class of Stock [Line Items]
Common shares reserved for future issuance	5,354,000	5,354,000