Segment Information (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014 Segment	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting [Abstract]
Number of segments									3
Revenue, Major Customer [Line Items]
Total revenues	$ 10,585	$ 9,857	$ 9,252	$ 9,037	$ 9,884	$ 8,018	$ 8,632	$ 8,766	$ 38,731	$ 35,300	$ 36,046
Concentration Risk, Percentage									10.00%
Group, Voluntary & Worksite Benefits | One Group, Voluntary & Worksite Benefits Customer [Member]
Revenue, Major Customer [Line Items]
Total revenues									$ 2,800	$ 2,500	$ 2,500
Group, Voluntary & Worksite Benefits | One Group, Voluntary & Worksite Benefits Customer [Member] | Premiums, universal life and investment-type product policy fees and other revenues [Member]
Revenue, Major Customer [Line Items]
Concentration Risk, Percentage									11.00%	10.00%	11.00%