Investment And Other Income (Components Of Investment And Other Income (Loss)) (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, 2022	Apr. 30, 2021	Jun. 30, 2022
Successor [Member]
Interest and dividend income			$ 6		$ 8
Pension benefit		$ 13	25		50
OPEB costs		(17)	(5)		(8)
OPEB remeasurement gain			96		150
All other, net		2			(1)
Investment and other income (loss), net		$ (2)	$ 122		$ 199
Predecessor [Member]
Pension benefit	$ 2			$ 6
OPEB costs	(1)			(4)
All other, net	(2)			(1)
Investment and other income (loss), net	$ (1)			$ 1