Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Deferred tax assets:
Net operating loss carryforwards	$ 229,535	$ 113,397
Tax credit carryforwards	155,334	124,922
Research expense capitalization	161,588	176,094
Lease liabilities	9,819	11,760
Stock-based compensation	67,511	57,766
Fixed assets	8,588	6,671
Accruals and other	14,111	13,447
Gross deferred tax assets	646,486	504,057
Valuation allowance	(630,806)	(487,714)
Net deferred tax assets	15,681	16,343
Deferred tax liabilities:
Lease right-of-use assets	(15,681)	(16,343)
Net deferred tax assets	$ 0	$ 0