Income Taxes - Components of Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Federal and California NOL carryforwards	$ 371,499	$ 230,994
Federal and California research and development credit carryforwards	97,548	83,589
Foreign NOL carryforwards	977	472
Share-based compensation expense	16,718	13,572
Depreciation	3,250	3,015
Lease liability	1,922	2,200
Other, net	17,596	1,217
Total deferred tax assets	509,510	335,059
Deferred tax liabilities:
Right-of-use assets	(1,777)	(2,051)
Equity investment	(4,119)	(2,512)
Total deferred tax liabilities	(5,896)	(4,563)
Net deferred tax assets	503,614	330,496
Valuation allowance	$ (503,614)	$ (330,496)