Investments (Net Investment Income - Narrative) (Details) (Actively Traded Securities At Estimated Fair Value And Fvo General Account Securities [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Actively Traded Securities At Estimated Fair Value And Fvo General Account Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities, Change in Unrealized Holding Gain (Loss)	$ (14)	$ 4	$ 44