Guaranteed Benefit Features - Universal and Variable Life Contracts (Details) - Variable Life and Universal Life - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Secondary Guarantees
Net Amount at Risk by Product and Guarantee [Line Items]
Account value (general and separate account)	$ 3,309.2	$ 3,335.1
Net amount at risk, net of reinsurance	$ 16,955.1	$ 16,851.1
Weighted average attained age	62 years	61 years
Paid-up Guarantees
Net Amount at Risk by Product and Guarantee [Line Items]
Account value (general and separate account)	$ 0.0	$ 0.0
Net amount at risk, net of reinsurance	$ 0.0	$ 0.0
Weighted average attained age	0 years	0 years