Investments (Details 3) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
The scheduled maturities of available for sale fixed maturities
Fixed maturities amortized cost, One year or less	$ 791
Fixed maturities fair value, One year or less	806
Fixed maturities fair value, One year or less, Percent	3.00%
Fixed maturities amortized cost, After one year through five years	5,374
Fixed maturities fair value, After one year through five years	5,735
Fixed maturities fair value, After one year through five years, Percent	25.00%
Fixed maturities amortized cost, After five years through ten years	6,399
Fixed maturities fair value, After five years through ten years	7,068
Fixed maturities fair value, After five years through ten years, Percent	31.00%
Fixed maturities amortized cost, After ten years	2,070
Fixed maturities fair value, After ten years	2,297
Fixed maturities fair value, After ten years, Percent	10.00%
Fixed maturities amortized cost, Subtotal	14,634
Fixed maturities fair value, Subtotal	15,906
Fixed maturities fair value, Subtotal, Percent	69.00%
Fixed maturities amortized cost, MBS	6,739
Fixed maturities fair value, MBS	7,075
Fixed maturities fair value, MBS, Percent	31.00%
Fixed maturities [Member]
The scheduled maturities of available for sale fixed maturities
Amortized Cost	21,373	20,562
Fair Value	$ 22,981	$ 21,807
Fair value, Total, Percent	100.00%

Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Fair Value, Percent.

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Mortgage-backed securities, amortized cost.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the second fiscal year through the fifth fiscal year following the latest fiscal year. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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