Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance	$ 17.5		$ (4.6)		$ (11.9)		$ 11.4
Change in component during the period before reclassifications	(8.6)		11.9		22.0		(1.4)
Amounts reclassified from AOCI	(0.1)		(1.7)		(1.3)		(4.4)
Accumulated Other Comprehensive Income (Loss), ending balance	8.8		5.6		8.8		5.6
Net Unrealized Investment Losses [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance	2.4	[1]	1.5	[1]	2.0	[1]	(1.3)	[1]
Change in component during the period before reclassifications	0.8	[1]	0.5	[1]	2.0	[1]	3.6	[1]
Amounts reclassified from AOCI	(0.2)	[1]	(0.1)	[1]	(1.0)	[1]	(0.4)	[1]
Accumulated Other Comprehensive Income (Loss), ending balance	3.0	[1]	1.9	[1]	3.0	[1]	1.9	[1]
Portion of OTTI Losses Recognized in OCI [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance	15.1	[1]	(6.1)	[1]	(13.9)	[1]	12.7	[1]
Change in component during the period before reclassifications	(9.4)	[1]	11.4	[1]	20.0	[1]	(5.0)	[1]
Amounts reclassified from AOCI	0.1	[1]	(1.6)	[1]	(0.3)	[1]	(4.0)	[1]
Accumulated Other Comprehensive Income (Loss), ending balance	$ 5.8	[1]	$ 3.7	[1]	$ 5.8	[1]	$ 3.7	[1]

[1] See Note 6 to these interim unaudited financial statements for additional information regarding offsets to net unrealized investment gains and losses which include policyholder dividend obligation, DAC and other actuarial offsets, and deferred income tax expense (benefit).