Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Property and equipment	$ 6	$ 18
Accruals and reserves	197	283
Deferred rent	1,599	1,601
Compensation and benefits	16,391	13,925
Deferred revenue	5,973	5,338
Net operating loss and credits	78,983	51,931
Other	1,559	701
Total deferred tax assets	104,708	73,797
Valuation allowance	(86,580)	(72,683)
Total deferred tax assets	18,128	1,114
Deferred tax liabilities:
Property and equipment	(599)	(529)
Convertible Notes	(14,598)	0
Other deferred tax liabilities	(2,822)	(587)
Deferred tax liabilities	(18,019)	(1,116)
Total		$ (2)
Total	$ 109