Accrued Expenses (Schedule Of Reconciliation Of Beginning And Ending Balances Of Accrued Expenses Associated With Asset Impairments And Costs Associated With Exit And Disposal Activities) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Loss on asset impairments	$ 519	$ 223	$ 101,282
Accrued Freight	1,547	2,091
Asset Impairments(b)
Restructuring Reserve [Roll Forward]
Beginning balance	0	0	0
Cash spend	0	0	0
Charges against assets	(882)	(141)	(101,595)
Ending balance	$ 0	$ 0	0
Flexible Packaging Films [Member]
Restructuring Cost and Reserve [Line Items]
Loss on asset impairments			$ 101,000

Accrued Expenses (Schedule Of Reconciliation Of Beginning And Ending Balances Of Accrued Expenses Associated With Asset Impairments And Costs Associated With Exit And Disposal Activities) (Details) - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2019

Dec. 31, 2018

Dec. 31, 2017

Restructuring Cost and Reserve [Line Items]

Loss on asset impairments

$ 519

$ 223

$ 101,282

Accrued Freight

1,547

2,091