Stock Plans 2 (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Summary Of Stock Options Outstanding And Exercisable By Exercise Price Range [Line Items]
Options Outstanding number of shares	14,471,464	14,506,522
Options Outstanding Per Share Weighted Average Exercise Price	$ 36.42	$ 37.38
Options exercisable number of shares	11,478,630
Options exercisable Per Share Weighted Average Exercise Price	$ 39.13
Total stock-based compensation expense for stock options [Line Items]
Pre-tax stock-based compensation	$ 18,948	$ 20,452	$ 21,761
Director Stock Plan [Abstract]
Annual grant of restricted commons stock to non employee directors	662,049
Granted	1,312,910
Stock-based compensation expense, net	12,778	13,187	14,303
Directors Plan [Member]
Director Stock Plan [Abstract]
Annual grant of restricted commons stock to non employee directors	2,200
Granted	22,000	26,400	26,400
Stock-based compensation expense, net	400	400	400
Minimum Restricted Common Stock Required Under Stock Plan	7,500
Stock Compensation Plan Member
Total stock-based compensation expense for stock options [Line Items]
Pre-tax stock-based compensation	4,663	5,371	6,649
Restricted Stock [Member]
Total stock-based compensation expense for stock options [Line Items]
Pre-tax stock-based compensation	14,285	15,081	14,888
Employee Stock Purchase Plans [Member]
Total stock-based compensation expense for stock options [Line Items]
Pre-tax stock-based compensation	$ 0	$ 0	$ 224
Range Of Per Share 22.09 To 30.99 [Member]
Summary Of Stock Options Outstanding And Exercisable By Exercise Price Range [Line Items]
Options Outstanding number of shares	3,986,021
Weighted Average remaining contractual life of the options outstanding	8.0
Weighted Average remaining contractual life of the options exercisable	7.4
Options Outstanding Per Share Weighted Average Exercise Price	$ 24.23
Options exercisable number of shares	1,370,704
Options exercisable Per Share Weighted Average Exercise Price	$ 23.78
Range Of Per Share 31.00 To 36.99 [Member]
Summary Of Stock Options Outstanding And Exercisable By Exercise Price Range [Line Items]
Options Outstanding number of shares	3,207,738
Weighted Average remaining contractual life of the options outstanding	3.6
Weighted Average remaining contractual life of the options exercisable	3.3
Options Outstanding Per Share Weighted Average Exercise Price	$ 34.71
Options exercisable number of shares	2,830,221
Options exercisable Per Share Weighted Average Exercise Price	$ 34.42
Range Of Per Share 37.00 To 42.99 [Member]
Summary Of Stock Options Outstanding And Exercisable By Exercise Price Range [Line Items]
Options Outstanding number of shares	3,842,311
Weighted Average remaining contractual life of the options outstanding	2.4
Weighted Average remaining contractual life of the options exercisable	2.4
Options Outstanding Per Share Weighted Average Exercise Price	$ 41.12
Options exercisable number of shares	3,842,311
Options exercisable Per Share Weighted Average Exercise Price	$ 41.12
Range Of Per Share 43.00 To 48.03 [Member]
Summary Of Stock Options Outstanding And Exercisable By Exercise Price Range [Line Items]
Options Outstanding number of shares	3,435,394
Weighted Average remaining contractual life of the options outstanding	4.7
Weighted Average remaining contractual life of the options exercisable	3.7
Options Outstanding Per Share Weighted Average Exercise Price	$ 46.90
Options exercisable number of shares	3,435,394
Options exercisable Per Share Weighted Average Exercise Price	$ 46.90