Income Taxes - Components of the Company's Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating loss carryforwards	$ 295,430	$ 190,555
Research and investment credits	62,710	46,729
Accruals and reserves	17,508	15,278
Depreciation	2,532	2,223
Intangible assets		164
Stock-based compensation	9,622	7,354
Interest expense	9,705	8,650
Total deferred tax assets	397,507	270,953
Deferred tax liabilities:
Intangible assets	(2,474)	(2,546)
Convertible debt	(16,911)	(21,873)
Capitalized costs	(27,665)	(17,009)
Depreciation	(234)	(231)
Total deferred tax liabilities	(47,284)	(41,659)
Valuation allowance	(346,381)	(227,062)
Net deferred tax assets	$ 3,842	$ 2,232