Investments (Details 22) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Variable Interest Entity [Line Items]
Total Assets	$ 84,541	$ 86,010
Total Liabilities	86,334	88,167
Real estate joint ventures [Member]
Variable Interest Entity [Line Items]
Total Assets	150	61
Total Liabilities	157	79
Other limited partnership interests [Member]
Variable Interest Entity [Line Items]
Total Assets	4,436	4,340
Total Liabilities	5,908	6,084
Trading securities [Member]
Variable Interest Entity [Line Items]
Total Assets	563	671
Total Liabilities	563	671
Mortgage loans, net [Member]
Variable Interest Entity [Line Items]
Total Assets	351	456
Total Liabilities	351	456
Other invested assets [Member]
Variable Interest Entity [Line Items]
Total Assets	1,117	799
Total Liabilities	1,431	1,194
Structured securities (RMBS, CMBS, and ABS) [Member]
Variable Interest Entity [Line Items]
Total Assets	72,605	74,685
Total Liabilities	72,605	74,685
US and foreign corporate securities [Member]
Variable Interest Entity [Line Items]
Total Assets	5,287	4,998
Total Liabilities	5,287	4,998
Non-redeemable preferred stock [Member]
Variable Interest Entity [Line Items]
Total Assets	32	0
Total Liabilities	$ 32	$ 0