Separate Accounts, Death Benefits and Other Insurance Benefit Features and Embedded Product Derivatives - Narrative (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Insurance [Abstract]
Assets Supporting Fixed Indexed Annuities, Fair Value	$ 1,800,000,000		$ 1,800,000,000		$ 1,800,000,000
Assets transferred to pension plan trustee					464,200,000
Fair value of embedded derivatives	62,800,000		62,800,000		51,200,000
Embedded derivatives gains and (losses) recognized in earnings	$ 5,900,000	$ (23,500,000)	$ 5,300,000	$ (500,000)