Income Taxes - Provision For (Benefit From) Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ 0	$ (26)	$ (252)
State	505	352	172
Total current	505	326	(80)
Deferred:
Federal	(1,200)	0	0
Total deferred	(1,200)	0	0
Total (benefit from) provision for income taxes	$ (695)	$ 326	$ (80)