Discontinued Operations - EPS (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	125,000	125,000		125,000	125,000
Income (Loss) Allocated to Participating Unvested Restricted Common Shares	$ 0.0	$ 0.0		$ 0.0	$ 0.8
Net Income (Loss) Available to Common Stockholders, Basic	$ (58.9)	$ 51.3		$ 29.7	$ 242.3
Total average common shares outstanding during the period	5,890,100	6,091,400		5,951,100	6,140,900
Average unvested restricted common shares	0	0		0	(77,700)
Basic earnings per share denominator	5,890,100	6,091,400		5,951,100	6,063,200
Average outstanding dilutive options to acquire common shares	0	0		0	0
Diluted earnings (loss) per share denominator	5,890,100	6,091,400		5,951,100	6,063,200
Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements			125,000
Net loss from discontinued operations, net of tax	$ 14.2	$ 63.9		$ 91.5	$ 176.5
Income (Loss) Allocated to Participating Unvested Restricted Common Shares	(0.2)	0.9		1.0	(2.2)
Net Income (Loss) Available to Common Stockholders, Basic	$ 14.0	$ 63.0		$ 90.5	$ 174.3
Total average common shares outstanding during the period	5,890,100	6,091,400		5,951,100	6,140,900
Average unvested restricted common shares	(70,900)	(81,300)		(67,100)	(77,700)
Basic earnings per share denominator	5,819,200	6,010,100		5,884,000	6,063,200
Average outstanding dilutive options to acquire common shares	0	0		0	0
Diluted earnings (loss) per share denominator	5,819,200	6,010,100		5,884,000	6,063,200
Earnings Per Share, Basic and Diluted	$ 2.41	$ 10.49		$ 15.37	$ 28.74