Income Taxes (Schedule of Income Tax Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Federal current	$ 237	$ 32,090	$ 51,260
State current	2,928	5,665	6,606
Foreign current	534	1,250	220
Current income tax expense (benefit), total	3,699	39,005	58,086
Federal deferred	42,895	33,912	4,503
State deferred	1,737	4,530	535
Deferred income tax expense (benefit), total	44,632	38,442	5,038
Total income tax expense	$ 48,331	$ 77,447	$ 63,124