Income Taxes - Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ 0	$ 0	$ 0
State	8	14	0
Foreign	(119)	197	493
Total current provision	(111)	211	493
Deferred:
Federal	0	0	0
State	0	0	0
Foreign	0	0	0
Total deferred provision	0	0	0
Total (benefit) provision	$ (111)	$ 211	$ 493