Income Taxes - Schedule of Components of Income Tax Expense/(Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal									$ 12,747	$ 27,611	$ 11,704
State									4,783	5,550	2,454
Foreign									276	93	(703)
Current income tax expense/(benefit)									17,806	33,254	13,455
Deferred:
Federal									(4,151)	5,783	(27,764)
State									907	(7,554)	(3,758)
Foreign									4,485	(1,254)	939
Deferred income tax expense/(benefit)									1,241	(3,025)	(30,583)
Total income tax expense/(benefit)	$ 13,696	$ 7,365	$ 567	$ (2,581)	$ 57,141	$ (31,423)	$ 4,906	$ (395)	$ 19,047	$ 30,229	$ (17,128)