Deferred Policy Acquisition Costs, Value of Business Acquired and Other Policy-Related Intangibles (DAC and VOBA by Segment) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred Policy Acquisition Costs and Present Value of Future Profits [Abstract]
DAC & VOBA	$ 5,975	$ 6,416	$ 5,832
Retail
Deferred Policy Acquisition Costs and Present Value of Future Profits [Abstract]
DAC & VOBA	5,544	5,990	5,407
Group, Voluntary & Worksite Benefits
Deferred Policy Acquisition Costs and Present Value of Future Profits [Abstract]
DAC & VOBA	324	333	337
Corporate Benefit Funding
Deferred Policy Acquisition Costs and Present Value of Future Profits [Abstract]
DAC & VOBA	106	93	88
Corporate & Other
Deferred Policy Acquisition Costs and Present Value of Future Profits [Abstract]
DAC & VOBA	$ 1	$ 0	$ 0