Restructuring And Other Charges (Schedule Of Reconciliation Of The Beginning And Ending Balances Of Accrued Restructuring Charges) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring And Other Charges [Abstract]
Balance at the beginning of the period	$ 7	$ 6
Costs incurred	15	17	$ 21
Costs paid or otherwise settled	(21)	(17)
Balance at the end of the period	$ 2	$ 7	$ 6