Business Segments - Segment Net Income (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Income (Loss) from Continuing Operations	$ 29.1	$ (18.3)	$ 4.1	$ (2.2)	$ 1.3	$ 38.0	$ 27.4	$ 13.5	$ 12.7	$ 80.2	$ 112.6
Net Operating Income									12.4	69.9	97.1
Income (Loss) from Continuing Operations									12.7	80.2	112.6
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Operating Income									27.4	98.4	116.7
Operating Segments [Member] | Property and Casualty Insurance [Member]
Segment Reporting Information [Line Items]
Income (Loss) from Continuing Operations									(2.9)	26.7
Net Operating Income											24.9
Operating Segments [Member] | Life and Health Insurance [Member]
Segment Reporting Information [Line Items]
Income (Loss) from Continuing Operations									30.3	71.7
Net Operating Income											91.8
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Net Operating Income									(15.0)	(28.5)	(19.6)
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Net Realized Gains on Sales of Investments									21.5	33.9	25.4
Net Impairment Losses Recognized in Earnings									(21.2)	(17.7)	(9.9)
Loss from Early Extinguishment of Debt									$ 0.0	$ (5.9)	$ 0.0