Income Taxes - Components of Federal and State Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current expense
Federal taxes	$ 44,779	$ 23,579	$ 16,592
State taxes	10,936	5,275	2,562
Total current provision	55,715	28,854	19,154
Deferred expense (benefit)
Federal taxes	(47,056)	(744)	1,636
State taxes	(5,819)	(384)	1,361
Total deferred provision	(52,875)	(1,128)	2,997
Income tax expense on continuing operations	$ 2,840	$ 27,726	$ 22,151
Effective tax rate	146.00%	40.40%	39.50%