Income Taxes - Summary of Tax Effects of Temporary Differences Portions of Company's Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating losses	$ 66,170	$ 41,419
Tax credits	26,254	23,359
Stock-based compensation	22,299	25,208
Accrued compensation and related expenses	3,513	4,061
Financing obligation- leased facility	0	29,842
Lease liabilities	31,355	0
Intangible assets	72,226	0
Other	2,003	463
Total deferred tax assets:	223,820	124,352
Valuation allowance	(174,921)	(81,127)
Total deferred tax assets, net of valuation allowance:	48,899	43,225
Deferred tax liabilities:
Depreciation and amortization	(8,708)	(26,844)
Goodwill	(23,047)	(19,307)
Right-of-use assets	(19,077)	0
Total deferred tax liabilities:	(50,832)	(46,151)
Total net deferred tax liabilities:	$ (1,933)	$ (2,926)