Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance	$ (11.9)		$ 11.4
Change in component during the period before reclassifications	(2.0)		(13.3)
Amounts reclassified from AOCI	(0.9)		(2.7)
Accumulated Other Comprehensive Income (Loss), ending balance	(14.8)		(4.6)
Net Unrealized Gains / (Losses) on Investments where Credit-related OTTI was Recognized [1]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance	2.0	[1]	(1.3)	[1]
Change in component during the period before reclassifications	1.0	[1]	1.3	[1]
Amounts reclassified from AOCI	(0.6)	[1]	(0.1)	[1]
Accumulated Other Comprehensive Income (Loss), ending balance	2.4	[1]	(0.1)	[1]
Net Unrealized Gains / (Losses) on All Other Investments [1]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance	(13.9)	[1]	12.7	[1]
Change in component during the period before reclassifications	(3.0)	[1]	(14.6)	[1]
Amounts reclassified from AOCI	(0.3)	[1]	(2.6)	[1]
Accumulated Other Comprehensive Income (Loss), ending balance	$ (17.2)	[1]	$ (4.5)	[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).