Income Taxes - Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current income taxes:
Federal	$ (258)	$ (1,315)	$ 49,529
State	33	1,317	5,728
Foreign	(554)	844	879
Total current income tax expense (benefit)	(779)	846	56,136
Deferred income taxes:
Federal	(49,115)	(38,100)	15,164
State	7,611	11,075	10,734
Total deferred income tax expense (benefit)	(41,504)	(27,025)	25,898
Total income tax expense (benefit)	(42,283)	(26,179)	82,034
Income tax benefit related to discontinued operation	$ 5,900	$ 14,200	$ 500