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		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Investments [Abstract]
Balance as of beginning of year	$ 437	$ 410	$ 424	$ 390
Increases attributable to:
Credit losses on securities for which an OTTI was not previously recognized	19	21	20	56
Credit losses on securities for which an OTTI was previously recognized	5	19	21	42
Decreases attributable to:
Securities sold	(48)	(35)	(52)	(73)
Balance as of end of period	$ 413	$ 415	$ 413	$ 415