Share-Based Compensation (Summary Of Stock Option Activity) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012
Share-Based Compensation [Abstract]
Shares, Beginning Balance	2,286
Shares, Granted	304
Shares, Exercised	(181)
Shares, Forfeited	(19)
Shares, Ending Balance	2,390
Shares, Exercisable	1,553
Shares, Vested and expected to vest	2,265
Weighted Average Exercise Price, Beginning Balance	$ 30.11
Weighted Average Exercise Price, Granted	$ 32.90
Weighted Average Exercise Price, Exercised	$ 20.12
Weighted Average Exercise Price, Forfeited	$ 30.34
Weighted Average Exercise Price, Ending Balance	$ 31.22
Weighted Average Exercise Price, Exercisable	$ 33.30
Weighted Average Exercise Price, Vested and expected to vest	$ 31.18
Weighted Average Remaining Life, Ending Balance, in years	5.8
Weighted Average Remaining Life, Exercisable, in years	4.4
Weighted Average Remaining Life, Vested and expected to vest, in years	5.6
Aggregate Intrinsic Value, Ending Balance	$ 25,890
Aggregate Intrinsic Value, Exercisable	16,367
Aggregate Intrinsic Value, Vested and expected to vest	$ 25,044