Investments (Fixed Maturity and Equity Securities Available-For-Sale - Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Summary of Certain Fixed Maturity Securities
Gross Unrealized OTTI Loss	$ (8)	$ 76	$ 112
Available-for-sale Securities, Debt Securities	350,889	351,402
Foreign Corporate Debt Securities [Member]
Summary of Certain Fixed Maturity Securities
Gross Unrealized OTTI Loss	(1)	2
Available-for-sale Securities, Debt Securities	57,057	57,198
Gross Unrealized Gain	3,132	3,019
RMBS (1)
Summary of Certain Fixed Maturity Securities
Gross Unrealized OTTI Loss	(10)	59
Available-for-sale Securities, Debt Securities	36,993	38,797
Gross Unrealized Gain	1,244	1,366
CMBS (1)
Summary of Certain Fixed Maturity Securities
Gross Unrealized OTTI Loss	(1)	(1)
Available-for-sale Securities, Debt Securities	11,272	12,633
Gross Unrealized Gain	282	347
Non-income producing fixed maturity securities
Summary of Certain Fixed Maturity Securities
Available-for-sale Securities, Debt Securities	6	54
Gross Unrealized Gain	$ (2)	$ 12