Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 117,433	$ 67,493
Research and development tax credit carryforward	12,246	6,978
Equity compensations	4,193	1,514
Reserves and accruals	10,804	6,988
Lease liabilities	16,184
Intangible assets	23,006	9,733
Deferred tax assets	183,866	92,706
Deferred tax liabilities:
ROU assets	(16,147)
Property and equipment	(2,570)	(1,553)
IPR&D	(8,511)	(8,647)
Deferred tax liabilities	(27,228)	(10,200)
Valuation allowance	(159,891)	(85,811)
Net deferred tax liabilities	$ (3,253)	$ (3,305)