Income Taxes (Reconciliation Of Provision For Income Taxes) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Taxes [Abstract]
Consolidated tax provision at federal statutory rate (in hundredths)	21.00%	21.00%	21.00%	21.00%
State income tax provisions, net of federal income tax expense (benefit)	(792.50%)	(0.70%)	11.50%	1.30%
Changes in certain deferred tax balances (in hundredths)	1317.20%	(0.60%)	(13.90%)	(1.80%)
Interest expense deduction (in hundredths)	(1592.10%)		22.60%
Restructuring cost	694.10%		(10.30%)
Goodwill impairment (in hundredths)		(15.90%)		(10.70%)
Loss on disposal of Northwest Operations (in hundredths)		1.80%	(8.10%)	(1.20%)
Tax reserve adjustment (in hundredths)		(0.10%)	(0.70%)
Shared-based payments (in hundredths)			(0.30%)	(0.10%)
Federal research and development tax credit (in hundredths)		0.30%	(0.50%)
All other, net (in hundredths)	16.20%	(0.20%)	(0.70%)
Effective tax rate (in hundredths)	(336.10%)	5.60%	20.60%	8.50%