Income Taxes (Reconciliation Of Provision For Income Taxes) (Details)	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Successor [Member]
Consolidated tax provision at federal statutory rate		21.00%
State income tax provisions, net of federal income tax benefit		3.10%
Tax reserve adjustment		0.10%
Changes in certain deferred tax balances		(8.20%)
Federal research and development tax credit		(0.40%)
All other, net		1.60%
Effective tax rate		17.20%
Predecessor [Member]
Consolidated tax provision at federal statutory rate	21.00%		21.00%	21.00%
State income tax provisions, net of federal income tax benefit	0.50%		21.70%	2.60%
Tax reserve adjustment			(0.70%)
Fresh start and reorganization adjustments	(24.90%)
Changes in certain deferred tax balances			(35.80%)	(2.30%)
Interest expense deduction			30.70%
Restructuring cost	0.30%		(10.00%)
Goodwill impairment				(11.80%)
Loss on disposal of Northwest Operations			(9.10%)
Shared-based payments			(0.20%)	(0.10%)
Federal research and development tax credit			(0.50%)
All other, net			0.10%
Effective tax rate	(3.10%)		17.20%	9.40%