Repurchases Of Common Stock (Summary Of Authorized Stock Repurchases) (Details) (USD $)	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013
Summary Of Authorized Stock Repurchases [Roll Forward]
Authorized repurchase - as of January 1, 2013		$ 133,640,000
Additional board authorization		250,000,000
Proceeds from the exercise of stock options	1,256,000	11,775,000
Repurchase of common stock from open market	(23,616,000)	(95,004,000)
Authorized repurchase - as of September 30, 2013	$ 300,411,000	$ 300,411,000