Goodwill And Other Intangibles (Schedule Of Goodwill Activity) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 7,205
Goodwill, Ending Balance	7,166
Connecticut Operations [Member]
Goodwill [Line Items]
Connecticut Acquisition (Note 3)	(53)
Goodwill, Ending Balance	815
Other Acquisitions [Member]
Goodwill [Line Items]
Other Acquisition	$ 14