Investments (Components of Net Investment Gains Losses) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	$ (34)	$ (56)	$ (155)	$ (297)
Fixed maturity securities - net gains (losses) on sales and disposals	(44)	80	504	146
Equity securities - net gains (losses) on sales and disposals	3	12	2	39
Net investment gains (losses)	(75)	36	351	(112)
Other net investment gains (losses):
Trading and other securities FVO general account securities - changes in estimated fair value	1	1	9	4
Mortgage Loans	(13)	0	22	49
Real estate and real estate joint ventures	4	(15)	(19)	(35)
Other limited partnership interests	0	(7)	(41)	(18)
Other investment portfolio gains (losses)	12	15	46	(20)
Subtotal - investment portfolio gains (losses)	(71)	30	368	(132)
FVO CSEs - changes in estimated fair value subsequent to consolidation:
Commercial mortgage loans	(14)	9	(46)	8
Securities	1	0	1	0
Long-term debt - related to commercial mortgage loans	18	(2)	66	8
Long-term debt - related to trading securities	(1)	8	(1)	(2)
Non-investment portfolio gains (losses)	(18)	(23)	(49)	(34)
Subtotal FVO CSEs and non-investment portfolio gains (losses)	(14)	(8)	(29)	(20)
Total net investment gains (losses)	(85)	22	339	(152)
Fixed maturity securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	(34)	(47)	(133)	(271)
Net investment gains (losses)	(78)	33	371	(125)
Utility Domestic Corporate Debt Securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	(1)	(10)	(33)	(61)
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	(3)	(4)	(11)	(16)
Communications Domestic Corporate Debt Securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	0	(1)	(2)	(19)
Industrial Domestic Corporate Debt Securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	0	(4)	0	(5)
Transportation Domestic Corporate Debt Securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	(3)	(11)	(3)	(17)
Corporate fixed maturity securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	(7)	(30)	(59)	(150)
RMBS [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	(27)	(15)	(74)	(61)
CMBS [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	0	0	0	(50)
ABS [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	0	(2)	0	(9)
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	0	(9)	(22)	(26)
Net investment gains (losses)	3	3	(20)	13
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	$ 0	$ (9)	$ (2)	$ (26)