Income Taxes (Components Of Provision For Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Current, Federal	$ 112,414	$ 99,783	$ 93,853
Current, State	7,879	8,338	7,733
Current, Foreign	18,843	17,479	17,854
Deferred, Federal	(7,387)	(13,368)	(14,472)
Deferred, State	(584)	(1,036)	(1,987)
Deferred, Foreign	5,278	3,483	1,263
Total	$ 136,443	$ 114,679	$ 104,244