Retirement Plans (Schedule Of Net Periodic Benefit Cost (Credit) For Pension And Postretirement Plans) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Defined Benefit Plan [Abstract]
Interest cost	$ 0	$ 1	$ 2	$ 3
Expected return on plan assets	(1)	(2)	(3)	(4)
Pension termination-related expense	28	0	28	0
Amortization of net actuarial loss	0	1	0	1
Net periodic cost	$ 27	$ 0	$ 27	$ 0