Investment and Other Income (Loss), Net (Components Of Investment And Other Income (Loss)) (Details) - USD ($) $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2021	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022
Investment and Other Income (Loss), Net [Abstract]
Interest and dividend income		$ 1	$ 87	$ 42
Pension benefit	6	52	19	75
OPEB costs	(4)	(50)	(9)	(18)
OPEB remeasurement (loss) gain			(3)	248
Pension remeasurement gain			(3)	248
Pension remeasurement gain			202	218
All other, net	(1)	(8)	(18)	(11)
Total investment and other income (loss), net	$ 1	$ (5)	$ 278	$ 554