Valuation And Qualifying Accounts And Reserves (Schedule Of Valuation And Qualifying Accounts) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Balance at Beginning of Year	$ 84	$ 73	$ 72
Additions	26	44	3
Deductions	(19)	(26)	(6)
Other	19	(7)	4
Balance at End of Year	$ 110	$ 84	$ 73