Common Stock (Schedule Of Weighted Average Remaining Contractual Life For Options Outstanding And Weighted Average Exercise Price Per Share For Exercisable Options) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Shares	7,558,945		6,594,950	8,802,450	8,116,326
Options Outstanding, Weighted Average Exercise Price Per Share	$ 31.63		$ 25.16	$ 25.03	$ 22.68
Options Outstanding, Weighted Average Remaining Contractual Life (in Years)	2.8
Exercisable Options, Shares	2,979,945
Weighted average exercise price per share, Options Exercisable	$ 23.82
Expected to Vest Options , Shares	4,160,480	[1]
Expected to Vest Options, Weighted Average Exercise Price Per Share	$ 36.71	[1]
Weighted average forfeiture rate	9.14%
$16.22 - $24.45 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Shares	2,642,825
Options Outstanding, Weighted Average Exercise Price Per Share	$ 19.56
Options Outstanding, Weighted Average Remaining Contractual Life (in Years)	1.5
Exercisable Options, Shares	2,050,825
Weighted average exercise price per share, Options Exercisable	$ 20.53
Expected to Vest Options , Shares	537,891	[1]
Expected to Vest Options, Weighted Average Exercise Price Per Share	$ 16.22	[1]
Range, Low	$ 16.22
Range, High	$ 24.45
$25.32 - $29.26 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Shares	29,500
Options Outstanding, Weighted Average Exercise Price Per Share	$ 26.80
Options Outstanding, Weighted Average Remaining Contractual Life (in Years)	1.1
Exercisable Options, Shares	17,750
Weighted average exercise price per share, Options Exercisable	$ 26.59
Expected to Vest Options , Shares	10,676	[1]
Expected to Vest Options, Weighted Average Exercise Price Per Share	$ 27.12	[1]
Range, Low	$ 25.32
Range, High	$ 29.26
$29.60 - $32.28 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Shares	2,139,120
Options Outstanding, Weighted Average Exercise Price Per Share	$ 31.15
Options Outstanding, Weighted Average Remaining Contractual Life (in Years)	2.9
Exercisable Options, Shares	911,370
Weighted average exercise price per share, Options Exercisable	$ 31.16
Expected to Vest Options , Shares	1,115,534	[1]
Expected to Vest Options, Weighted Average Exercise Price Per Share	$ 31.14	[1]
Range, Low	$ 29.60
Range, High	$ 32.28
$38.12 - $43.67 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Shares	2,728,000
Options Outstanding, Weighted Average Exercise Price Per Share	$ 43.59
Options Outstanding, Weighted Average Remaining Contractual Life (in Years)	4.1
Expected to Vest Options , Shares	2,478,661	[1]
Expected to Vest Options, Weighted Average Exercise Price Per Share	$ 43.59	[1]
Range, Low	$ 38.12
Range, High	$ 43.67
$46.79 - $54.79 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Shares	19,500
Options Outstanding, Weighted Average Exercise Price Per Share	$ 52.99
Options Outstanding, Weighted Average Remaining Contractual Life (in Years)	4.3
Expected to Vest Options , Shares	17,718	[1]
Expected to Vest Options, Weighted Average Exercise Price Per Share	$ 52.99	[1]
Range, Low	$ 46.79
Range, High	$ 54.79

[1] Assumes a weighted average forfeiture rate of 9.14%.