Investments (Net Investment Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
The Components of Net Investment Income
Fixed maturity securities	$ 3,826	$ 3,808
Equity securities	24	32
Trading securities - actively traded and FVO general account securities	21	45
Mortgage loans	738	830
Policy loans	155	158
Real estate and real estate joint ventures	193	177
Other limited partnership interests	246	182
Cash, cash equivalents and short-term investments	49	36
International joint ventures	(14)	3
Other	63	41
Subtotal	5,301	5,312
Less: Investment expenses	300	259
Subtotal, net	5,001	5,053
Trading securities - FVO contractholder-directed unit-linked investments	1,039	1,015
Securitized reverse residential mortgage loan	0	85
FVO consolidated securitization entities - changes in estimated fair value included in net investment gains (losses):
Commercial mortgage loans	37	45
Securities	0	2
Subtotal	1,076	1,147
Net investment income	6,077	6,200
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	13	29
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	$ 956	$ 877

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The amount of equity method investment earnings on the investment in a non-consolidated joint ventures.

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Reflects the total sum of all other revenue and income recognized by the entity in the period not otherwise specified in the income statement.

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Reflects net investment income (the sum of all other revenue and income recognized by the entity less related expenses).

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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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Subtotal of securities and loans held by consolidated securitization entities.

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The net change during the reporting period in the aggregate market value of equity or debt securities held by consolidated securitization entities that are purchased and held principally for the purpose of selling them in the near future.

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Securitized reverse residential mortgage loan.

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The amount of investment earnings, including realized gain (loss), recognized in the period on trading securities - FVO contractholder-directed unit-linked investments.

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Total expenses related to the generation of investment income in debt and equity securities.

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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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The amount of investment earnings, excluding realized and unrealized gain (loss), recognized in the period on holdings of equity securities, net of related investment expenses.

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The amount of investment earnings, excluding realized and unrealized gain (loss), recognized in the period on real estate held for investment purposes, net of related investment expenses.

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The amount of investment earnings, excluding realized and unrealized gain (loss), recognized in the period on investments that the entity intends to hold for at least a year which are not otherwise specified in the disclosed schedule of investments, net of related investment expenses.

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The sum of the realized and unrealized net gain (loss) on trading securities during the period.

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