Investment And Other Income (Components Of Investment And Other Income) (Details) - USD ($) $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended	4 Months Ended	6 Months Ended
	Apr. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	Apr. 30, 2021	Jun. 30, 2020
Successor [Member]
Pension and OPEB benefit (costs)		$ (4)
All other, net		2
Investment and other income, net		$ (2)
Predecessor [Member]
Interest and dividend income			$ 2		$ 4
Pension and OPEB benefit (costs)	$ 1		(20)	$ 2	(19)
All other, net	(2)		(2)	(1)
Investment and other income, net	$ (1)		$ (20)	$ 1	$ (15)