Investments and Derivative Instruments (Details 4) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Available-for-sale Securities, Amortized Cost
One year or less, amortized cost	$ 2,240
Over one year through five years, amortized cost	15,331
Over five years through ten years, amortized cost	15,641
Over ten years, amortized cost	27,675
Subtotal, amortized cost	60,887
Mortgage-backed and asset-backed securities, amortized cost	19,953
Total fixed maturities, AFS, amortized cost	80,840
Available-for-sale Securities, Fair Value
One year or less, fair value	2,277
Over one year through five years, fair value	16,139
Over five years through ten years, fair value	16,905
Over ten years, fair value	30,540
Subtotal, fair value	65,861
Mortgage-backed and asset-backed securities, fair value	19,366
Total fixed maturities, AFS, fair value	$ 85,227	$ 81,809

Available for sale securities debt maturities before mortgage backed and asset backed securities amortized cost.

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