Investments (Fixed Maturity and Equity Securities Available-For-Sale - Narrative) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Summary of Certain Fixed Maturity Securities
Gross Unrealized OTTI Loss	$ 84	$ 112	$ 218
Available-for-sale Securities, Debt Securities	366,275	365,425
CMBS (1)
Summary of Certain Fixed Maturity Securities
Gross Unrealized OTTI Loss	(1)	(1)
Available-for-sale Securities, Debt Securities	13,311	14,332
Gross Unrealized Gain	605	615
Foreign corporate
Summary of Certain Fixed Maturity Securities
Gross Unrealized OTTI Loss	7	7
Available-for-sale Securities, Debt Securities	60,494	61,675
Gross Unrealized Gain	4,781	4,651
Non-income producing fixed maturity securities [Member]
Summary of Certain Fixed Maturity Securities
Available-for-sale Securities, Debt Securities	78	64
Gross Unrealized Gain	$ 31	$ 28