Investments (Details 26) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
The Components of Net Investment Income
Fixed maturity securities	$ 3,808	$ 3,683
Equity securities	32	30
Trading securities - actively traded and FVO general account securities	45	28
Mortgage loans	830	759
Policy loans	158	160
Real estate and real estate joint ventures	178	147
Other limited partnership interests	182	243
Cash, cash equivalents and short-term investments	36	46
International joint ventures	3	(21)
Other	41	(32)
Subtotal	5,313	5,043
Less: Investment expenses	260	245
Subtotal, net	5,053	4,798
Trading securities - FVO contractholder-directed unit-linked investments	1,015	419
Securitized reverse residential mortgage loan	85	0
FVO consolidated securitization entities:
Commercial mortgage loans	45	95
Securities	2	1
Subtotal	1,147	515
Net investment income	6,200	5,313
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	29	21
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	$ 877	$ 316

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The amount of investment earnings, excluding realized and unrealized gain (loss), recognized in the period on commercial mortgage loans held by consolidated securitization entities, net of related investment expenses.

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Securitized reverse residential mortgage loan.

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Aggregate amount of net income allocated to limited partners.

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The income earned from investments in securities and property, equipment and other capital assets. It includes rent from property and equipment, dividends from shares in corporations, and interest from bonds, loans, mortgages, derivatives, commercial paper, bank accounts, certificates of deposits, treasuries, and other financial securities. It does not include realized gains and losses on investments.

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