Investments (Unconsolidated Variable Interest Entities) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Variable Interest Entity [Line Items]
Total Assets	$ 78,143	$ 84,541
Total Liabilities	80,263	86,334
Real estate joint ventures [Member]
Variable Interest Entity [Line Items]
Total Assets	106	150
Total Liabilities	110	157
Other limited partnership interests [Member]
Variable Interest Entity [Line Items]
Total Assets	4,925	4,436
Total Liabilities	6,782	5,908
Trading securities [Member]
Variable Interest Entity [Line Items]
Total Assets	598	563
Total Liabilities	598	563
Mortgage loans, net [Member]
Variable Interest Entity [Line Items]
Total Assets	162	351
Total Liabilities	162	351
Other invested assets [Member]
Variable Interest Entity [Line Items]
Total Assets	1,348	1,117
Total Liabilities	1,607	1,431
Structured securities (RMBS, CMBS, and ABS) [Member]
Variable Interest Entity [Line Items]
Total Assets	66,535	72,605
Total Liabilities	66,535	72,605
U.S. corporate and foreign corporate securities [Member]
Variable Interest Entity [Line Items]
Total Assets	4,437	5,287
Total Liabilities	4,437	5,287
Non-redeemable preferred stock [Member]
Variable Interest Entity [Line Items]
Total Assets	32	32
Total Liabilities	$ 32	$ 32