Business Segments (Schedule Of Depreciation And Amortization, Capital Expenditures) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Depreciation and Amortization	$ 26,402	$ 23,784	$ 31,957
Capital Expenditures	36,875	27,361	23,355
Depreciation and Amortization, Discontinued Operations	0	0	5,511
Capital Expenditure, Discontinued Operations	0	0	1,912
PE Films
Segment Reporting Information [Line Items]
Depreciation and Amortization	6,280	6,263	6,762
Capital Expenditures	3,289	2,997	6,024
Aluminum Extrusions
Segment Reporting Information [Line Items]
Depreciation and Amortization	17,414	15,326	17,403
Capital Expenditures	23,664	18,914	10,260
Subtotal
Segment Reporting Information [Line Items]
Depreciation and Amortization	26,138	23,577	25,926
Capital Expenditures	35,104	27,514	21,243
General corporate
Segment Reporting Information [Line Items]
Depreciation and Amortization	264	207	520
Capital Expenditures	1,771	(153)	200
Flexible Packaging Films
Segment Reporting Information [Line Items]
Depreciation and Amortization	2,444	1,988	1,761
Capital Expenditures	$ 8,151	$ 5,603	$ 4,959

Amount of capital expenditure attributable to discontinued operations.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5B
-Subparagraph (c)(2)
-URI https://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760

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Amount of deprecation and amortization expense attributable to property, plant and equipment and intangible assets of discontinued operations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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-Topic 205
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The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (e)
-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 230
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-Section 45
-Paragraph 13
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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