Share-Based Compensation (Narrative) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Jun. 03, 2009
Total number of shares authorized by the shareholders			27.0
Remains available for future incentive awards	9.1
Average fair value of stock options granted, in dollars per share	$ 13.99	$ 10.16
Vesting period, in years	3
Aggregate intrinsic value of options exercised, in USD	$ 76.2	$ 142.1
Number Of Shares To Companys Target Award Level For Eligible Employees	1.3
Stock Option [Member]
Total unrecognized compensation cost from stock option arrangements granted under the plan, in USD	21.5
Restricted Stock Units (RSUs) [Member]
Total unrecognized compensation cost from stock option arrangements granted under the plan, in USD	24.2
Performance Shares [Member]
Total unrecognized compensation cost from stock option arrangements granted under the plan, in USD	$ 21.8
Stock Appreciation Rights (SARs) [Member]
Vesting period, in years	10
Vested stock grants outstanding [Member]
Vested Stock Grants Outstanding	45,099