7. Investing Activities (Details 6) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012	Sep. 30, 2011 As restated and amended [Member]	Sep. 30, 2011 As restated and amended [Member]
Total other-than-temporary debt impairment losses	$ (0.7)	$ (4.4)	$ (4.7)	$ (7.0)
Portion of loss recognized in OCI	(0.3)	1.8	3.7	4.7
Net debt impairment losses recognized in earnings	(1.0)	(2.6)	(1.0)	(2.3)
Debt security impairments:
U.S. government and agency
State and political subdivision
Foreign government
Corporate
CMBS		(0.1)
RMBS	(0.8)	(2.1)	(0.8)	(1.8)
CDO/CLO	(0.1)	(0.1)
Other asset-backed	(0.1)	(0.3)		(0.1)
Net debt security impairments	(1.0)	(2.6)	(1.0)	(2.3)
Limited partnerships and other investment impairments
Impairment losses	(1.0)	(2.6)	(1.0)	(2.3)
Debt security transaction gains	20.8	21.4	0.2	2.4
Debt security transaction losses	(0.1)			(0.6)
Limited partnerships and other investment gains
Limited partnerships and other investment losses	(0.3)
Net transaction gains	20.4	20.8	0.2	1.9
Derivative instruments	(18.0)	(33.5)	34.8	23.2
Embedded derivatives (1)	6.6	6.1	(48.3)	(41.0)
Related party reinsurance derivatives	(4.2)	(3.5)	10.1	10.1
Net realized investment gains (losses), excluding impairment losses	4.8	(10.1)	(3.2)	(5.8)
Net realized investment gains (losses), including impairment losses	$ 3.8	$ (12.7)	$ (4.2)	$ (8.1)