Equity Incentive Plans (Schedule Of Stock Option Outstanding And Exercisable) (Details) (USD $)	Dec. 31, 2011 years	Dec. 31, 2010 years	Dec. 31, 2009 years	Dec. 31, 2008 years
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	4,356,985	4,947,348	5,169,653	5,206,374
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	3.0	3.7	4.6	5.6
Exercisable Shares, Outstanding	4,139,531
Weighted Average Exercise Price	$ 28.86	$ 27.93	$ 27.71	$ 27.72
2005 Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	4,356,985
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	3.0
Exercisable Shares, Outstanding	4,139,531
11.34 [Member] | 2005 Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	10,240
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	1.0
Exercisable Shares, Outstanding	10,240
Weighted Average Exercise Price	$ 11.34
16.28 [Member] | 2005 Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	154,376
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	0.1
Exercisable Shares, Outstanding	154,376
Weighted Average Exercise Price	$ 16.28
17.29 [Member] | 2005 Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	10,240
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	0.0
Exercisable Shares, Outstanding	10,240
Weighted Average Exercise Price	$ 17.29
19.93 [Member] | 2005 Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	336,164
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	1.1
Exercisable Shares, Outstanding	336,164
Weighted Average Exercise Price	$ 19.93
23.37 [Member] | 2005 Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	654,495
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	6.1
Exercisable Shares, Outstanding	437,041
Weighted Average Exercise Price	$ 23.37
24.80 [Member] | 2005 Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	884,056
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	1.8
Exercisable Shares, Outstanding	884,056
Weighted Average Exercise Price	$ 24.80
28.70 [Member] | 2005 Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	477,000
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	2.1
Exercisable Shares, Outstanding	477,000
Weighted Average Exercise Price	$ 28.70
32.26 [Member] | 2005 Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	10,000
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	2.5
Exercisable Shares, Outstanding	10,000
Weighted Average Exercise Price	$ 32.26
32.47 [Member] | 2005 Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	245,060
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	3.2
Exercisable Shares, Outstanding	245,060
Weighted Average Exercise Price	$ 32.47
33.54 [Member] | 2005 Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	264,694
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	3.4
Exercisable Shares, Outstanding	264,694
Weighted Average Exercise Price	$ 33.54
37.00 [Member] | 2005 Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	610,800
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	3.0
Exercisable Shares, Outstanding	610,800
Weighted Average Exercise Price	$ 37.00
38.38 [Member] | 2005 Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	15,000
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	2.9
Exercisable Shares, Outstanding	15,000
Weighted Average Exercise Price	$ 38.38
36.90 [Member] | 2005 Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	258,630
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	3.8
Exercisable Shares, Outstanding	258,630
Weighted Average Exercise Price	$ 36.90
36.24 [Member] | 2005 Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	414,230
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	4.1
Exercisable Shares, Outstanding	414,230
Weighted Average Exercise Price	$ 36.24
38.26 [Member] | 2005 Incentive Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Shares, Outstanding	12,000
Weighted-Average Remaining Contractual Life, Outstanding (in Years)	4.3
Exercisable Shares, Outstanding	12,000
Weighted Average Exercise Price	$ 38.26