Share Repurchase Program (Schedule Of Shares Repurchased) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Proceeds from (Repurchase of) Equity [Abstract]
Shares repurchased	2,743	367	8,047	3,673
Average price per share	$ 200.70	$ 281.04	$ 235.26	$ 261.32
Total investment	$ 550,530	$ 102,941	$ 1,893,068	$ 959,743