Share Repurchase Program (Schedule Of Shares Repurchased) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Proceeds from (Repurchase of) Equity [Abstract]
Shares repurchased	3,475	2,075	5,304	3,306
Average price per share	$ 245.26	$ 262.17	$ 253.13	$ 259.14
Total investment	$ 852,226	$ 544,165	$ 1,342,538	$ 856,802