Investments (Details 42) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Variable Interest Entity [Line Items]
Total Assets	$ 7,353	$ 11,080
Total Liabilities	3,231	6,995
Consolidated securitization entities [Member]
Variable Interest Entity [Line Items]
Total Assets	3,397	7,114
Total Liabilities	3,204	6,892
MRSC collateral financing arrangement [Member]
Variable Interest Entity [Line Items]
Total Assets	3,317	3,333
Total Liabilities	0	0
Other limited partnership interests [Member]
Variable Interest Entity [Line Items]
Total Assets	343	319
Total Liabilities	7	85
Real estate joint ventures [Member]
Variable Interest Entity [Line Items]
Total Assets	13	20
Total Liabilities	19	17
Other invested assets [Member]
Variable Interest Entity [Line Items]
Total Assets	102	108
Total Liabilities	1	1
Trading Account Assets [Member]
Variable Interest Entity [Line Items]
Total Assets	181	186
Total Liabilities	$ 0	$ 0