Income Taxes - Summary of Company's Net Deferred Tax Assets (Liabilities) (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Deferred tax assets:
Net operating loss carryforwards	$ 296,766	$ 258,664
Research and development credit carryforwards	200,816	151,333
Section 174 capitalized research	216,469	150,993
Operating lease liability	57,438	31,183
Deferred revenue	10,634	9,633
Stock-based compensation	34,827	30,408
Accruals and allowances	5,468	6,244
Prepaid rent	4,410	1,190
Equity investment adjustments	16,560	7,580
Intangibles, including in-process research and development	920	1,017
Capitalized start-up costs	211	249
Gross deferred tax assets	844,519	648,494
Deferred tax asset valuation allowance	(783,211)	(616,082)
Total deferred tax assets	61,308	32,412
Deferred tax liabilities:
Fixed assets	(1,385)	(1,221)
Operating lease right-of-use assets	(59,923)	(31,191)
Total deferred tax liabilities	(61,308)	(32,412)
Net deferred tax asset (liability)	$ 0	$ 0