Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating loss (NOL) carryforwards	$ 78,961	$ 86,898
Research and development tax credits carryforwards	16,761	11,261
Capitalized research and development expenses	5,135	6,840
Accrued compensation	28,970	24,038
Lease liabilities	8,012	6,112
Other	20,608	12,096
Total deferred tax assets	158,447	147,245
Deferred tax liabilities:
Convertible senior notes	0	(11,224)
Fixed assets	(3,847)	(7,675)
Other	(8,177)	(6,719)
Total deferred tax liabilities	(12,024)	(25,618)
Less valuation allowance	(146,423)	(121,627)
Net deferred tax assets	$ 0	$ 0