Earnings (Loss) Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Computations of basic and diluted earnings per share for income from continuing operations
Net income (loss)	$ 8.0	$ (6.1)
Add: Loss from discontinued operations	7.8	15.4
Income from continuing operations	$ 15.8	$ 9.3
Weighted-average shares outstanding - basic	50.3	50.9
Effect of diluted securities attributable to stock-based payments	0.7	0
Weighted-average shares outstanding - diluted	51.0	50.9
Earnings per share:
Income from continuing operations, Basic	$ 0.32	$ 0.18
Loss from discontinued operations, Basic	$ (0.16)	$ (0.30)
Net income (loss), Basic	$ 0.16	$ (0.12)
Income from continuing operations, Diluted	$ 0.31	$ 0.18
Loss from discontinued operations, Diluted	$ (0.15)	$ (0.30)
Net income (loss), Diluted	$ 0.16	$ (0.12)