Retirement Plans (Narrative) (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	Dec. 31, 2021
Successor [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Capitalization of pension and OPEB expense		$ 4			$ 11
OPEB Remeasurement			$ 96		150
Predecessor [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Capitalization of pension and OPEB expense	$ 1			$ 7
Pension [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to plans					74
Decrease in plan assets					(545)
Investment returns					506
Plan assets			$ 2,110		2,110	$ 2,655
Benefit payments					$ 113