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Financial Instruments Financial Instruments (Summary of Location and Fair Value of Currency Forward Derivative Financial Instruments - Terphane (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Flexible Packaging Films [Member] [Domain] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Amount of pre-tax gain (loss) recognized in other comprehensive income | $ 0 | $ 0 | $ 0
Aluminum Futures Contracts [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Amount of pre-tax gain (loss) recognized in other comprehensive income | 1,501 | 394 | (5,055)
Selling, General and Administrative Expenses [Member] | Flexible Packaging Films [Member] [Domain] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Amount of pre-tax gain (loss) reclassified from accumulated other comprehensive income to net income (effective portion) | (43) |  |
Amount of pre-tax gain (loss) recognized in other comprehensive income | (561) |  |
Cost of Sales [Member] | Flexible Packaging Films [Member] [Domain] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Amount of pre-tax gain (loss) reclassified from accumulated other comprehensive income to net income (effective portion) | 62 | 62 | 62
Cost of Sales [Member] | Aluminum Futures Contracts [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Amount of pre-tax gain (loss) reclassified from accumulated other comprehensive income to net income (effective portion) | $ 1,210 | $ (1,630) | $ (3,538)

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- Definition The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4D -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624177-113959 + Details
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- Definition The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959 + Details
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- Definition 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. + References No definition available. + Details
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