Investments (Fixed Maturity and Equity Securities Available-For-Sale - Narrative) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary of Certain Fixed Maturity Securities
Available-for-sale Securities, Debt Securities	$ 188,911	$ 173,746
Gross Unrealized OTTI Loss	66	149	256
Asset-backed Securities [Member]
Summary of Certain Fixed Maturity Securities
Available-for-sale Securities, Debt Securities	8,226	7,824
Gross Unrealized OTTI Loss	0	(1)
Gross Unrealized Gain	102	151
Fixed maturity securities
Summary of Certain Fixed Maturity Securities
Available-for-sale Securities, Debt Securities	6	38
Gross Unrealized Gain	$ 5	$ 12