Stock-Based Compensation Stock Option Awards Outstanding (Details) (USD $)	12 Months Ended
	Dec. 31, 2012
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding	3,041,227
Outstanding Options, Weighted Average Remaining Contractual Term	4 years 11 months 17 days
Outstanding Options, Weighted Average Exercise Price	$ 21.92
Options Exercisable	2,323,902
Exercisable Options, Weighted Average Exercise Price	$ 23.27
Option Range 1 Of Exercise Prices [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Range, Lower Range Limit	$ 10.09
Exercise Price Range, Upper Range Limit	$ 16.54
Options Outstanding	583,575
Outstanding Options, Weighted Average Remaining Contractual Term	6 years 10 months 10 days
Outstanding Options, Weighted Average Exercise Price	$ 14.94
Options Exercisable	297,950
Exercisable Options, Weighted Average Exercise Price	$ 14.91
Option Range 2 Of Exercise Prices [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Range, Lower Range Limit	$ 16.55
Exercise Price Range, Upper Range Limit	$ 17.63
Options Outstanding	483,925
Outstanding Options, Weighted Average Remaining Contractual Term	4 years 11 months 24 days
Outstanding Options, Weighted Average Exercise Price	$ 17.39
Options Exercisable	371,258
Exercisable Options, Weighted Average Exercise Price	$ 17.56
Option Range 3 Of Exercise Prices [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Range, Lower Range Limit	$ 17.64
Exercise Price Range, Upper Range Limit	$ 19.49
Options Outstanding	460,600
Outstanding Options, Weighted Average Remaining Contractual Term	6 years 5 months 10 days
Outstanding Options, Weighted Average Exercise Price	$ 18.47
Options Exercisable	310,100
Exercisable Options, Weighted Average Exercise Price	$ 18.19
Option Range 4 Of Exercise Prices [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Range, Lower Range Limit	$ 19.50
Exercise Price Range, Upper Range Limit	$ 21.91
Options Outstanding	550,377
Outstanding Options, Weighted Average Remaining Contractual Term	5 years 8 months 10 days
Outstanding Options, Weighted Average Exercise Price	$ 21.31
Options Exercisable	460,377
Exercisable Options, Weighted Average Exercise Price	$ 21.66
Option Range 5 Of Exercise Prices [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Range, Lower Range Limit	$ 21.92
Exercise Price Range, Upper Range Limit	$ 28.92
Options Outstanding	579,300
Outstanding Options, Weighted Average Remaining Contractual Term	3 years 8 months
Outstanding Options, Weighted Average Exercise Price	$ 23.88
Options Exercisable	500,767
Exercisable Options, Weighted Average Exercise Price	$ 24.08
Option Range 6 Of Exercise Prices [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Range, Lower Range Limit	$ 28.93
Exercise Price Range, Upper Range Limit	$ 43.22
Options Outstanding	383,450
Outstanding Options, Weighted Average Remaining Contractual Term	1 year 0 months 20 days
Outstanding Options, Weighted Average Exercise Price	$ 40.29
Options Exercisable	383,450
Exercisable Options, Weighted Average Exercise Price	$ 40.29