Stock Based Compensation - Summary of Stock-Based Compensation Expense by Grant Type and by Function Included within Consolidated Statements of Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Subtotal	$ 30,287	$ 16,396	$ 91,990	$ 104,570
Capitalized stock-based compensation costs	(3,544)	(1,469)	(11,376)	(11,190)
Total stock-based compensation expense included in expenses	26,743	14,927	80,614	93,380
Research and development	82,549	218,890	327,767	1,196,730
Selling, general and administrative	118,612	91,893	335,163	363,419
Location, Statement of Income, Balance [Axis]: us-gaap:ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense included in expenses	8,509	4,139	27,295	36,733
Location, Statement of Income, Balance [Axis]: us-gaap:SellingGeneralAndAdministrativeExpense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense included in expenses	18,234	10,788	53,319	56,647
Employee Stock Option
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense included in expenses	5,663	8,939	17,737	33,517
Restricted and Performance Stock Units Member
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense included in expenses	24,145	10,724	73,774	70,381
Employee Stock Purchase Plan [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense included in expenses	$ 479	$ 3,267	$ 479	$ 672