Stock-based Compensation (Details 7) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Summary of stock appreciation rights
Compensation expense	$ 15.2	[1]	$ 13.7	[1]	$ 15.4	[1]
Weighted-average fair value of grants, per share	$ 48.64
Stock Appreciation Rights [Member]
Summary of stock appreciation rights
Compensation expense	$ 4.5		$ 5.4		$ 4.7
Weighted-average fair value of grants, per share	$ 14.34		$ 9.39		$ 13.75

[1] Stock-Based Compensation expense is recorded in our Corporate and other business segment.