Restructuring And Other Charges (Schedule Of Reconciliation Of The Beginning And Ending Balances Of Accrued Restructuring Charges) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Restructuring Cost and Reserve [Line Items]
Balance at the beginning of the period			$ 1	$ 7
Costs incurred	$ 2	$ 2	14	10
Costs paid or otherwise settled			(12)	(16)
Balance at the end of the period	$ 4	$ 1	$ 4	$ 1