Income Taxes - Components of Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current provision
Federal	$ 0	$ 0	$ 0
State	2,704	1,250	556
Foreign	1,901	116	0
Total current	4,605	1,366	556
Deferred provision
Federal	(269)	0	0
State	(891)	0	0
Foreign	(1,089)	(628)	0
Total deferred	(2,249)	(628)	0
Total provision for income taxes	$ 2,356	$ 738	$ 556