Investments (Unconsolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Variable Interest Entity [Line Items]
Carrying Amount Asset	$ 85,212	$ 76,597
Carrying Amount Liability	90,298	79,059
Other limited partnership interests
Variable Interest Entity [Line Items]
Carrying Amount Asset	6,348	5,186
Carrying Amount Liability	10,791	7,074
Other invested assets
Variable Interest Entity [Line Items]
Carrying Amount Asset	2,160	1,604
Carrying Amount Liability	2,770	2,161
FVO and trading securities
Variable Interest Entity [Line Items]
Carrying Amount Asset	541	586
Carrying Amount Liability	541	586
Real estate joint ventures
Variable Interest Entity [Line Items]
Carrying Amount Asset	251	65
Carrying Amount Liability	284	82
Common Stock [Member]
Variable Interest Entity [Line Items]
Carrying Amount Asset	157	0
Carrying Amount Liability	157	0
Other
Variable Interest Entity [Line Items]
Carrying Amount Asset	72	71
Carrying Amount Liability	72	71
Structured securities (RMBS, CMBS, and ABS)
Variable Interest Entity [Line Items]
Carrying Amount Asset	72,608	65,824
Carrying Amount Liability	72,608	65,824
U.S. corporate and foreign corporate securities
Variable Interest Entity [Line Items]
Carrying Amount Asset	3,075	3,261
Carrying Amount Liability	$ 3,075	$ 3,261