Stock Based Compensation - Summary of Stock-Based Compensation Expense by Grant Type Included within Consolidated Statements of Operations and Comprehensive Loss (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense included in expenses		$ 184,300	$ 182,514	$ 233,018
Subtotal		205,133	182,514	233,018
Capitalized stock-based compensation costs	[1]	(20,833)	0	0
Research and Development Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense included in expenses		74,010	82,489	61,293
Selling, General and Administrative Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense included in expenses		110,290	100,025	171,725
Employee Stock Option
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense included in expenses		62,255	79,472	174,868
Restricted Stock Awards/Units (RSAs/RSUs) [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense included in expenses		135,612	97,808	52,601
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		$ 7,266	$ 5,234	$ 5,549

[1] Prior to the year ended December 31, 2024, capitalized stock-based compensation costs were not material