Earnings Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Basic and diluted earnings per share
Income (loss) from continuing operations	$ 16.7		$ 18.7		$ 26.9		$ (2.8)
Weighted average common shares outstanding	92.6		92.0		93.1		91.9
Add: Weighted average restricted stock awards outstanding	0.2	[1]	0.6	[1]	0.3	[1]	0.6	[1]
Basic weighted average common shares outstanding	92.8		92.6		93.4		92.5
Add: Dilutive impact of stock options	1.1		0.8		1.3
Diluted weighted average common shares outstanding	93.9		93.4		94.7		92.5
Basic earnings (loss) per share from continuing operation	$ 0.18		$ 0.20		$ 0.29		$ (0.03)
Diluted earnings (loss) per share from continuing operation	$ 0.18		$ 0.20		$ 0.28		$ (0.03)

[1] Restricted stock awards containing rights to non-forfeitable dividends which participate in undistributed earnings with common shareholders are considered participating securities for purposes of computing earnings per share.