Invested Assets (Details 1) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Amortized cost and fair value of fixed maturities by contractual maturity [Abstract]
Due in one year or less, Amortized cost	$ 2,069
Due after one year through five years, Amortized cost	11,635
Due after five years through ten years, Amortized cost	11,595
Due after ten years, Amortized cost	7,105
Subtotal fixed maturities, Amortized cost	32,404
Due in one year or less, Fair value	2,101
Due after one year through five years, Fair value	12,274
Due after five years through ten years, Fair value	12,626
Due after ten years, Fair value	7,490
Subtotal fixed maturities, Fair value	34,491
Taxable, Amortized cost	16,337	15,989
Taxable, Fair value	17,271	16,745
Total fixed maturities, Amortized cost	35,216	35,061
Total fixed maturities, Fair value	37,405	36,519
Residential Mortgage-Backed Securities [Member]
Amortized cost and fair value of fixed maturities by contractual maturity [Abstract]
Taxable, Amortized cost	937	1,293
Taxable, Fair value	979	1,350
Commercial Mortgage-Backed Securities [Member]
Amortized cost and fair value of fixed maturities by contractual maturity [Abstract]
Taxable, Amortized cost	1,875	1,688
Taxable, Fair value	$ 1,935	$ 1,757

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Total of debt securities at amortized cost categorized neither as held-to-maturity nor trading securities, excluding mortgage-backed securities.

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Total of debt securities at fair value categorized neither as held-to-maturity nor trading securities, excluding mortgage-backed securities.

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This item represents total taxable debt securities that are categorized as neither held-to-maturity nor trading. Such securities are reported at fair value; unrealized gains and losses of such securities are excluded from earnings and included in other comprehensive income.

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For an unclassified balance sheet, total of debt securities categorized neither as held-to-maturity nor trading.

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