Income from Continuing Operations Per Unrestricted Share (Details) (USD $) In Millions, except Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	$ 3.8	$ 32.3	$ 44.8	$ 113.4
Amount of Dilutive Securities, Stock Options and Restrictive Stock Units	0	0	0	0
Net Income (Loss) Available to Common Stockholders, Diluted	3.8	32.1	44.6	112.8
Weighted Average Number of Shares Outstanding, Basic	60,141,400	61,457,800	60,312,600	61,865,900
Incremental Common Shares Attributable to Share-based Payment Arrangements	88,000	85,400	106,200	88,500
Weighted Average Number of Shares Outstanding, Diluted	60,229,400	61,543,200	60,418,800	61,954,400
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.06	$ 0.52	$ 0.74	$ 1.83
Income (Loss) from Continuing Operations, Per Diluted Share	$ 0.06	$ 0.52	$ 0.74	$ 1.82
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	0.6
Common Stock [Member]
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	$ 3.8	$ 32.1	$ 44.6	$ 112.8