Investments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 item	Dec. 31, 2012 item	Dec. 31, 2011
Total OTTI for AFS securities backed by pools of residential and commercial mortgages	$ 21	$ 103
OTTI for AFS securities backed by pools of residential and commercial mortgages recognized in OCI	(46)	(45)
OTTI for AFS securities backed by pools of residential and commercial mortgages recognized in net income (loss)	67	148
Increase in gross AFS securities unrealized losses	894
Trading Securities, Unrealized Holding Loss	(172)	53	118
Number of partnerships in alternative investment portfolio	121	98
Investment commitments	868
Investment commitments for limited partnerships	411
Investment commitments for private placements	372
Investment commitments for mortgage loans on real estate	85
Mortgage loans on real estate [Member]
Largest mortgage loan concentration in geographic region	32.00%	32.00%
Federal Home Loan Mortgage Corporation
Fair value	2,600	3,800
Concentration risk, percentage	3.00%	4.00%
Fannie Mae
Fair value	1,700	2,200
Concentration risk, percentage	2.00%	2.00%
Electric Industry [Member]
Fair value	8,700	8,700
Concentration risk, percentage	9.00%	9.00%
Banking Industry [Member]
Fair value	5,000	5,000
Concentration risk, percentage	5.00%	5.00%
Corporate bonds [Member]
Percentage of fair value rated as investment grade	96.00%	96.00%
Amortized cost of portfolio rated below investment grade	3,000	3,000
Fair value of portfolio rated below investment grade	2,900	2,900
CLOs [Member]
Percentage of fair value rated as investment grade	94.00%	93.00%
Amortized cost of portfolio rated below investment grade	16	21
Fair value of portfolio rated below investment grade	$ 13
Mortgage-backed securities [Member]
Projected default rate on existing delinquencies on MBS (low end of range)	10.00%	10.00%
Projected default rate on existing delinquencies on MBS (high end of range)	100.00%	100.00%
Severity of second lien loans	100.00%
Severity of first lien loans	30.00%