Investments (Details 26) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
The Components of Net Investment Income
Fixed maturity securities	$ 3,825	$ 3,770	$ 11,370	$ 11,244
Equity securities	26	28	96	106
Trading securities - actively traded and FVO general account securities	24	(38)	68	6
Mortgage loans	811	806	2,405	2,331
Policy loans	157	162	471	482
Real estate and real estate joint ventures	173	206	630	539
Other limited partnership interests	145	180	593	582
Cash, cash equivalents and short-term investments	40	41	115	131
International joint ventures	7	6	11	(8)
Other	27	82	148	151
Subtotal	5,235	5,243	15,907	15,564
Less: Investment expenses	276	268	793	762
Subtotal, net	4,959	4,975	15,114	14,802
Trading securities - FVO contractholder-directed unit-linked investments	512	(824)	1,010	(437)
Securitized reverse residential mortgage loan	3	0	177	0
FVO consolidated securitization entities:
Commercial mortgage loans	42	95	131	286
Securities	1	6	4	7
Subtotal	558	(723)	1,322	(144)
Net investment income	5,517	4,252	16,436	14,658
Actively traded securities and FVO general account securities [Member]
Changes in estimated fair value subsequent to purchase included in net investment income:
Changes in estimated fair value included in net investment income	6	(46)	36	(25)
FVO contractholder-directed unit-linked investments [Member]
Changes in estimated fair value subsequent to purchase included in net investment income:
Changes in estimated fair value included in net investment income	$ 247	$ (873)	$ 741	$ (641)

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