Investments (Schedule Of Changes in Amount Of Credit Losses Of OTTI Recognized In Net Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Investments [Abstract]
Balance as of beginning of period	$ 413	$ 382	$ 382	$ 380
Increases attributable to:
Credit losses on securities for which an OTTI was not previously recognized	26	3	61	16
Credit losses on securities for which an OTTI was previously recognized	2	4	7	6
Decreases attributable to:
Securities sold, paid down or matured	(10)	(15)	(19)	(28)
Balance as of end of period	$ 431	$ 374	$ 431	$ 374