Fair Value Measurements - Financial Instruments Excluding Guaranteed Living Benefits (Details 3) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value of assets accounted for using fair value option	$ 1,227	$ 649
ABS [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value of assets accounted for using fair value option	65	65
CDOs [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value of assets accounted for using fair value option	290	270
Foreign government/government agencies [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value of assets accounted for using fair value option	605	64
Corporate [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value of assets accounted for using fair value option	267	250
Credit-linked notes [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value of liabilities accounted for using fair value option	$ 44	$ 37