Repurchases Of Common Stock (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Repurchases Of Common Stock [Abstract]
Shares of common stock repurchases authorized	52,000,000
Remaining shares available for repurchase under authorization	2,961,827
Shares repurchased	3,952,000	1,474,000	3,419,000
Total cost of shares repurchased	$ 367,761	$ 132,268	$ 255,505
Average cost per share	$ 93.06	$ 89.72	$ 74.74
Shares acquired through employee surrenders	49,475	53,272	55,721
Cost of shares acquired through employee surrenders	$ 4,548	$ 4,662	$ 4,316