Goodwill And Other Intangibles (Schedule Of Goodwill Activity) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Goodwill And Other Intangibles [Abstract]
Goodwill, Beginning Balance		$ 9,674	$ 7,166
Goodwill, Acquired During the Period			2,508
Goodwill, Purchase Accounting Adjustments		98
Goodwill impairment	$ (2,078)	(2,748)
Goodwill, Ending Balance	$ 7,024	$ 7,024	$ 9,674