Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current:
Federal									$ 33,818	$ 37,331	$ 20,468
State									7,030	8,117	3,795
Foreign									58	161	183
Current Income Tax Expense (Benefit), Total									40,906	45,609	24,446
Deferred:
Federal									(11,620)	(8,641)	(1,582)
State									(1,901)	(1,317)	(4,041)
Foreign									556	335	1,567
Deferred Income Tax Expense (Benefit)									(12,965)	(9,623)	(4,056)
Total income tax expense from continuing operations	$ 7,336	$ 1,573	$ 9,542	$ 9,490	$ 7,514	$ 8,596	$ 10,049	$ 9,827	27,941	35,986	20,390
Total income tax benefit from discontinued operations									$ 0	$ 0	$ (2,935)