Investments (Details 46) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Variable Interest Entity [Line Items]
Total Assets	$ 85,385	$ 86,010
Total Liabilities	87,187	88,167
Real estate joint ventures [Member]
Variable Interest Entity [Line Items]
Total Assets	108	61
Total Liabilities	121	79
Other limited partnership interests [Member]
Variable Interest Entity [Line Items]
Total Assets	4,508	4,340
Total Liabilities	5,994	6,084
Trading securities [Member]
Variable Interest Entity [Line Items]
Total Assets	609	671
Total Liabilities	609	671
Mortgage loans, net [Member]
Variable Interest Entity [Line Items]
Total Assets	370	456
Total Liabilities	370	456
Other invested assets [Member]
Variable Interest Entity [Line Items]
Total Assets	920	799
Total Liabilities	1,223	1,194
U.S. corporate securities [Member]
Variable Interest Entity [Line Items]
Total Assets	2,892	2,911
Total Liabilities	2,892	2,911
Foreign corporate securities [Member]
Variable Interest Entity [Line Items]
Total Assets	2,005	2,087
Total Liabilities	2,005	2,087
RMBS [Member]
Variable Interest Entity [Line Items]
Total Assets	41,064	42,637
Total Liabilities	41,064	42,637
CMBS [Member]
Variable Interest Entity [Line Items]
Total Assets	19,017	19,069
Total Liabilities	19,017	19,069
ABS [Member]
Variable Interest Entity [Line Items]
Total Assets	13,892	12,979
Total Liabilities	$ 13,892	$ 12,979