Income from Continuing Operations Per Unrestricted Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Income (Loss) from Continuing Operations	$ (18.3)	$ 38.0	$ (16.4)	$ 78.9
Dilutive Effect on Income of Equity-based Compensation Equivalent Shares	0.0	0.0	0.0	0.0
Diluted Income (Loss) from Continuing Operations Attributed to Unrestricted Shares	$ (18.2)	$ 37.8	$ (16.1)	$ 78.6
Weighted-Average Unrestricted Shares Outstanding (shares)	51,122,500	51,611,800	51,140,600	51,737,600
Equity-based Compensation Equivalent Shares (shares)	0	60,200	0	78,200
Weighted-Average Unrestricted Shares and Equivalent Shares Outstanding Assuming Dilution (shares)	51,122,500	51,672,000	51,140,600	51,815,800
Basic Income (Loss) from Continuing Operations Per Unrestricted Share	$ (0.36)	$ 0.73	$ (0.31)	$ 1.52
Diluted Income (Loss) from Continuing Operations Per Unrestricted Share	$ (0.36)	$ 0.73	$ (0.31)	$ 1.52
Unrestricted Shares [Member]
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Income (Loss) from Continuing Operations	$ (18.2)	$ 37.8	$ (16.1)	$ 78.6
Participating Awards [Member]
Schedule of Basic and Diluted Earnings Per Share [Line Items]
Income (Loss) from Continuing Operations	$ (0.1)	$ 0.2	$ (0.3)	$ 0.3