Income Taxes - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal	$ 54,447	$ 106,710	$ 93,538
State	7,359	9,446	8,121
Foreign	(188)	217	265
Total Current	61,618	116,373	101,924
Deferred:
Federal	7,616	(59,517)	17,057
State	1,750	638	597
Foreign	2,891	(393)	(158)
Total Deferred	12,257	(59,272)	17,496
Total	$ 73,875	$ 57,101	$ 119,420