Investments (Unconsolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Carrying Amount Asset	$ 78,181	$ 80,983
Carrying Amount Liability	80,777	83,490
Other limited partnership interests
Variable Interest Entity [Line Items]
Carrying Amount Asset	6,004	6,250
Carrying Amount Liability	8,162	8,402
Other invested assets
Variable Interest Entity [Line Items]
Carrying Amount Asset	1,587	1,720
Carrying Amount Liability	2,007	2,050
FVO and trading securities
Variable Interest Entity [Line Items]
Carrying Amount Asset	577	565
Carrying Amount Liability	577	565
Real estate joint ventures
Variable Interest Entity [Line Items]
Carrying Amount Asset	72	100
Carrying Amount Liability	90	125
Mortgage loans
Variable Interest Entity [Line Items]
Carrying Amount Asset	34	51
Carrying Amount Liability	34	51
Structured securities (RMBS, CMBS, and ABS)
Variable Interest Entity [Line Items]
Carrying Amount Asset	66,544	68,427
Carrying Amount Liability	66,544	68,427
U.S. corporate and foreign corporate securities
Variable Interest Entity [Line Items]
Carrying Amount Asset	3,324	3,829
Carrying Amount Liability	3,324	3,829
Non-redeemable preferred stock
Variable Interest Entity [Line Items]
Carrying Amount Asset	39	41
Carrying Amount Liability	$ 39	$ 41