Investments (Schedule Of Changes in Amount Of Credit Losses Of OTTI Recognized In Net Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Investments [Abstract]
Balance as of beginning of period	$ 380	$ 404
Increases attributable to:
Credit losses on securities for which an OTTI was not previously recognized	13
Credit losses on securities for which an OTTI was previously recognized	2	4
Decreases attributable to:
Securities sold	(13)
Balance as of end of period	$ 382	$ 408