Income Taxes - Components of Income Tax Expense (Benefit) Attributable to Current Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
(Loss) income before income tax (benefit) expense	$ (2,185)	$ 11,559	$ 22,971
Current:
Federal tax	0	199	669
State tax	838	1,006	1,294
Foreign tax	148	270	103
Total current	986	1,475	2,066
Deferred:
Federal tax	(1,467)	26,348	6,811
State tax	(532)	(787)	41
Foreign tax	307	(171)	74
Total deferred	(1,692)	25,390	6,926
Income tax (benefit) expense	$ (706)	$ 26,865	$ 8,992