Income Taxes (Provision For Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current, Federal	$ 245,189	$ 284,489	$ 363,803
Current, State	24,898	28,406	37,811
Current, Foreign	21,138	19,017	12,826
Total Current	291,225	331,912	414,440
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Deferred, Federal	47,046	(4,250)	(15,474)
Deferred, State	2,688	7,038	(2,264)
Deferred, Foreign	1,121	(2,953)	1,254
Total, Deferred	50,855	(165)	(16,484)
Total Current and Deferred	$ 342,080	$ 331,747	$ 397,956