Business Segments - Segment Net Income (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Net Operating Income									$ 69.9	$ 97.1	$ 159.2
Income from Continuing Operations	$ 1.3	$ 38.0	$ 27.4	$ 13.5	$ 63.3	$ 4.8	$ 9.3	$ 35.2	80.2	112.6	214.5
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Operating Income									98.4	116.7	189.9
Operating Segments [Member] | Property and Casualty Insurance [Member]
Segment Reporting Information [Line Items]
Net Operating Income									26.7	24.9	100.6
Operating Segments [Member] | Life and Health Insurance [Member]
Segment Reporting Information [Line Items]
Net Operating Income									71.7	91.8	89.3
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Net Operating Income									(28.5)	(19.6)	(30.7)
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Net Realized Gains on Sales of Investments									33.9	25.4	64.4
Net Impairment Losses Recognized in Earnings									17.7	9.9	9.1
Loss from Early Extinguishment of Debt									$ (5.9)	$ 0.0	$ 0.0