Retirement Plans (Schedule Of Assumptions Used) (Details)	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2021	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Successor [Member]
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate - used at period end to value obligation (in hundredths)		2.90%	2.90%
Discount rate - used at beginning of period to compute (in hundredths)		3.10%
Expected long-term rate of return on plan assets (in hundredths)		7.50%
Rate of increase in compensation levels (in hundredths)		2.00%
Successor [Member] | Pension [Member]
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate - used at period end to value obligation (in hundredths)		2.90%	2.90%
Expected long-term rate of return on plan assets (in hundredths)			7.50%	7.50%
Successor [Member] | OPEB [Member]
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate - used at period end to value obligation (in hundredths)		3.00%	3.00%
Successor [Member] | OPEB [Member] | Minimum [Member]
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate - used at beginning of period to compute (in hundredths)		2.80%
Successor [Member] | OPEB [Member] | Maximum [Member]
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate - used at beginning of period to compute (in hundredths)		3.30%
Predecessor [Member] | Pension [Member]
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate - used at period end to value obligation (in hundredths)	3.10%			2.60%	3.40%
Discount rate - used at beginning of period to compute (in hundredths)	2.60%			3.40%	4.30%
Expected long-term rate of return on plan assets (in hundredths)	7.50%			7.50%	7.50%
Rate of increase in compensation levels (in hundredths)	2.00%			2.00%	2.00%
Predecessor [Member] | OPEB [Member]
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate - used at period end to value obligation (in hundredths)	3.30%
Predecessor [Member] | OPEB [Member] | Minimum [Member]
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate - used at period end to value obligation (in hundredths)				2.60%	3.40%
Discount rate - used at beginning of period to compute (in hundredths)	2.60%			3.40%	4.30%
Predecessor [Member] | OPEB [Member] | Maximum [Member]
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate - used at period end to value obligation (in hundredths)				2.80%	3.50%
Discount rate - used at beginning of period to compute (in hundredths)	2.80%			3.50%	4.40%