Investments (Components of Net Investment Gains Losses) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	$ (40)	$ (93)	$ (121)	$ (241)
Fixed maturity securities - net gains (losses) on sales and disposals	179	73	548	66
Equity securities - net gains (losses) on sales and disposals	5	21	(1)	27
Net investment gains (losses)	144	1	426	(148)
Other net investment gains (losses):
Trading and other securities FVO general account securities - changes in estimated fair value	4	(1)	8	3
Mortgage Loans	23	13	35	49
Real estate and real estate joint ventures	(9)	(16)	(23)	(20)
Other limited partnership interests	(41)	(9)	(41)	(11)
Other investment portfolio gains (losses)	27	(10)	34	(35)
Subtotal - investment portfolio gains (losses)	148	(22)	439	(162)
FVO CSEs - changes in estimated fair value subsequent to consolidation:
Commercial mortgage loans	(19)	(7)	(32)	(1)
Trading securities	1	1	0	(10)
Long-term debt - related to commercial mortgage loans	26	10	48	10
Non-investment portfolio gains (losses)	(46)	(46)	(31)	(11)
Subtotal FVO CSEs and non-investment portfolio gains (losses)	(38)	(42)	(15)	(12)
Total net investment gains (losses)	110	(64)	424	(174)
Fixed maturity securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	(39)	(91)	(99)	(224)
Net investment gains (losses)	140	(18)	449	(158)
Utility Domestic Corporate Debt Securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	(27)	(13)	(32)	(51)
Finance Domestic Corporate Debt Securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	0	0	(10)	(32)
Consumer Domestic Corporate Debt Securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	0	(9)	(8)	(12)
Communications Domestic Corporate Debt Securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	(2)	(1)	(2)	(18)
Industrial Domestic Corporate Debt Securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	0	0	0	(1)
Other Industries [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	0	(6)	0	(6)
Corporate fixed maturity securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	(29)	(29)	(52)	(120)
RMBS [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	(10)	(37)	(47)	(46)
CMBS [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	0	(20)	0	(50)
ABS [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	0	(5)	0	(7)
State and political subdivision securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	0	0	0	(1)
Equity Securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	(1)	(2)	(22)	(17)
Net investment gains (losses)	4	19	(23)	10
Non-redeemable preferred stock [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	0	0	(20)	0
Common Stock [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	$ (1)	$ (2)	$ (2)	$ (17)