Investment And Other Income (Loss) (Components Of Investment And Other Income) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Investment And Other Income (Loss) [Abstract]
Interest and dividend income	$ 2	$ 1	$ 4	$ 4
Pension and OPEB costs	(20)	(11)	(19)	(22)
All other, net	(2)	1
Total investment and other income (loss), net	$ (20)	$ (9)	$ (15)	$ (18)