Analysis of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss carryforwards	$ 304,033	$ 212,342
Difference in depreciation and amortization	40,095	55,162
Research and development tax credits	103,806	67,309
Stock-based compensation	24,114	15,538
Lease liabilities	15,796	4,831
Deferred revenue	939	888
Capitalized inventory	18,255	22,943
Other	16,270	15,727
Total deferred tax assets	523,308	394,740
Deferred tax liabilities:
Right of use asset	(10,782)
Debt discount	(23,099)	(25,162)
Total deferred tax liabilities	(33,881)	(25,162)
Valuation allowance	(488,829)	(369,345)
Net deferred tax assets	$ 598	$ 233