Restructuring And Other Charges (Schedule Of Reconciliation Of The Beginning And Ending Balances Of Accrued Restructuring Charges) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Restructuring And Other Charges [Abstract]
Balance at the beginning of the period	$ 1	$ 7
Costs incurred	4	6
Costs paid or otherwise settled	(1)	(7)
Balance at the end of the period	$ 4	$ 6