Investment And Other Income (Components Of Investment And Other Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		4 Months Ended	5 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Apr. 30, 2021	Sep. 30, 2021	Sep. 30, 2022
Successor [Member]
Interest and dividend income	$ 16	$ 1		$ 1	$ 24
Pension benefit	24	23		36	74
OPEB costs	(5)	(59)		(76)	(13)
OPEB remeasurement gain	84				234
Pension remeasurement gain	91				91
All other, net	1	(2)
Investment and other income (loss), net	$ 211	$ (37)		$ (39)	$ 410
Predecessor [Member]
Pension benefit			$ 6
OPEB costs			(4)
All other, net			(1)
Investment and other income (loss), net			$ 1