Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance	$ (14.8)		$ (4.6)		$ (11.9)		$ 11.4
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	32.6		0		30.6		(13.3)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(0.3)		0		(1.2)		(2.7)
Accumulated Other Comprehensive Income (Loss), ending balance	17.5		(4.6)		17.5		(4.6)
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]	(0.1)	[1]	2.0	[1]	(1.3)	[1]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0.2	[1]	1.8	[1]	1.2	[1]	3.1	[1]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(0.2)	[1]	(0.2)	[1]	(0.8)	[1]	(0.3)	[1]
Accumulated Other Comprehensive Income (Loss), ending balance	2.4	[1]	1.5	[1]	2.4	[1]	1.5	[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	(17.2)	[1]	(4.5)	[1]	(13.9)	[1]	12.7	[1]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	32.4	[1]	(1.8)	[1]	29.4	[1]	(16.4)	[1]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(0.1)	[1]	0.2	[1]	(0.4)	[1]	(2.4)	[1]
Accumulated Other Comprehensive Income (Loss), ending balance	$ 15.1	[1]	$ (6.1)	[1]	$ 15.1	[1]	$ (6.1)	[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).