XML 125 R74.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Financial Instruments (Schedule Of Pretax Effect On Net Income (Loss) And Other Comprehensive Income (Loss) Of Derivative Instruments Classified As Cash Flow Hedges) (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Foreign Currency Forwards And Options [Member] |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Amount of pre-tax gain (loss) recognized in other comprehensive income | $ 0 |  | $ (120)
Foreign Currency Forwards And Options [Member] | Cost of Sales |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Amount of pre-tax gain (loss) reclassified from accumulated other comprehensive income to net income (effective portion) | 62 | $ 62 | 16
Aluminum Futures Contracts |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Amount of pre-tax gain (loss) recognized in other comprehensive income | 394 | (5,055) | 542
Aluminum Futures Contracts | Cost of Sales |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Amount of pre-tax gain (loss) reclassified from accumulated other comprehensive income to net income (effective portion) | $ (1,630) | $ (3,538) | $ 631

X
- 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
Name: | us-gaap_DerivativeInstrumentsGainLossLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- 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=64837297&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=64837297&loc=SL5624177-113959 + Details
Name: | us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- 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=64837297&loc=SL5624171-113959 + Details
Name: | us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=tg_ForeignCurrencyForwardsAndOptionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_CostOfSalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=tg_AluminumFuturesContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |