Income Taxes - Components of Income Tax Benefit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
United States federal income taxes:
Current	$ 0	$ 0	$ (31)
Deferred	37	(561)	(11,855)
Foreign income taxes:
Current	74	34	68
Deferred	(204)	(230)	635
State income taxes:
Current	0	0	113
Deferred	11	(173)	(4,355)
Total income tax benefit from continuing operations	$ (82)	$ (930)	$ (15,425)