Income from Continuing Operations Per Unrestricted Share (Details) (USD $) In Millions, except Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	$ (1.5)	$ 39.1	$ 54.3	$ 86.8
Amount of Dilutive Securities, Stock Options and Restrictive Stock Units	0	0	0	0
Net Income (Loss) Available to Common Stockholders, Diluted	(1.5)	38.9	54.1	86.4
Weighted Average Number of Shares Outstanding, Basic	60,118,700	61,985,200	60,398,100	62,070,000
Incremental Common Shares Attributable to Share-based Payment Arrangements	0	98,900	115,400	90,100
Weighted Average Number of Shares Outstanding, Diluted	60,118,700	62,084,100	60,513,500	62,160,100
Income (Loss) from Continuing Operations, Per Basic Share	$ (0.03)	$ 0.63	$ 0.89	$ 1.39
Income (Loss) from Continuing Operations, Per Diluted Share	$ (0.03)	$ 0.63	$ 0.89	$ 1.39
Restricted Stock [Member]
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	0	0.2	0.2	0.4
Common Stock [Member]
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	$ (1.5)	$ 38.9	$ 54.1	$ 86.4