Provision for Income Taxes - Components Of The Provision For Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current
Federal	$ (46,931)	$ 116,637	$ 102,317
State	(8,336)	29,989	27,500
Other foreign countries	34,005	32,394	28,336
Provision for income taxes, Current	(21,262)	179,020	158,153
Deferred
Federal	51,447	(35,748)	707
State	12,080	(10,658)	(5,703)
Other foreign countries	(4,314)	(1,311)	955
Provision for income taxes, Deferred	59,213	(47,717)	(4,041)
Provision for income taxes	$ 37,951	$ 131,303	$ 154,112