Stock-Based Compensation (Company's Activities With Respect To Its Stock Options) (Details) (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 years	Dec. 31, 2010	Dec. 31, 2009
Stock-Based Compensation [Abstract]
Number of Shares Outstanding, Beginning Balance	3,786	4,196	3,786
Number of Shares, Granted	578	539	1,157
Number of Shares, Exercised	(704)	(889)	(659)
Number of Shares, Canceled	(52)	(60)	(88)
Number of Shares Outstanding, Ending Balance	3,608	3,786	4,196
Number of Shares Exercisable, at December 31, 2011	1,968
Number of Shares Unvested, at December 31, 2011	1,640
Weighted-Average Exercise Price Per Share Outstanding, Beginning Balance	$ 24.78	$ 21.77	$ 20.33
Weighted-Average Exercise Price Per Share, Granted	$ 41.91	$ 35.64	$ 20.26
Weighted-Average Exercise Price Per Share, Exercised	$ 21.53	$ 17.01	$ 9.69
Weighted-Average Exercise Price Per Share, Canceled	$ 32.07	$ 26.71	$ 30.43
Weighted-Average Exercise Price Per Share Outstanding, Ending Balance	$ 28.06	$ 24.78	$ 21.77
Weighted-Average Exercise Price Per Share Exercisable, at December 31, 2011	$ 24.32
Weighted-Average Exercise Price Per Share Unvested, at December 31, 2011	$ 32.54
Weighted-Average Remaining Contractual Life (in Years) Outstanding, at December 31, 2011	4.10
Weighted-Average Remaining Contractual Life (in years) Exercisable, at December 31, 2011	3.40
Weighted-Average Remaining Contractual Life (in years) Unvested, at December 31, 2011	5.10
Aggregate Intrinsic Value Outstanding, at December 31, 2011	53,772,000
Aggregate Intrinsic Value Exercisable, at December 31, 2011	36,682,000
Aggregate Intrinsic Value Outstanding, Unvested at December 31, 2011	$ 17,090,000