Shareholders' Equity and Stock-Based Compensation (Details 6) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended			1 Months Ended	12 Months Ended
	Dec. 31, 2009	Dec. 31, 2011	Dec. 31, 2010	Feb. 29, 2012 Common Stock In Treasury	Dec. 31, 2009 Common Stock In Treasury
Common stock repurchased (in shares)	2,625,000				2,625,000
Total cash consideration paid for common stock repurchased	$ 113.2				$ 113.2
Authorized repurchase amount under a written trading plan				350.0
Stock that may be repurchased prior to the completion of sale of Service Solutions Business				$ 75.0
Preferred Stock
Authorized no par value preferred stock (in shares)	3,000,000	3,000,000	3,000,000