Repurchases Of Common Stock (Summary Of Stock Repurchases) (Details) (USD $) In Thousands	0 Months Ended	3 Months Ended		9 Months Ended
	Jul. 19, 2011	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Equity, Class of Treasury Stock [Line Items]
Board Authorization	$ 250,000
Proceeds from the exercise of options		842	709	2,182	27,959
Repurchase from Accelerated Stock Repurchase Agreement ("ASR Agreement")				50,000
Board Authorization [Member]
Equity, Class of Treasury Stock [Line Items]
Authorized repurchase - as of January 1, 2011				74,486
Board Authorization				250,000
Proceeds from the exercise of options				2,182
Repurchase from open market				(13,349)
Repurchase from Accelerated Stock Repurchase Agreement ("ASR Agreement")				(50,000)
Authorized repurchase - as of September 30, 2011		$ 263,319		$ 263,319