XML 65 R47.htm IDEA: XBRL DOCUMENT v3.20.2

Derivative 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	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Foreign Currency Forwards And Options [Member] | Cost Of Sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) reclassified from accumulated other comprehensive income (loss) to net income effective portion)	$ 16	$ 16	$ 31	$ 31
Foreign Currency Forwards And Options [Member] | Selling, General and Administrative Expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) reclassified from accumulated other comprehensive income (loss) to net income effective portion)	(1,798)	(369)	(2,592)	(560)
Cash Flow Derivative Hedges | Aluminum Futures Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) recognized in other comprehensive income (loss)	(1,201)	(1,192)	(2,795)	(1,438)
Cash Flow Derivative Hedges | Aluminum Futures Contracts | Cost Of Sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) reclassified from accumulated other comprehensive income (loss) to net income effective portion)	(1,551)	(606)	(2,191)	(1,223)
Cash Flow Derivative Hedges | Foreign Currency Forwards And Options
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) recognized in other comprehensive income (loss)	0	0		0
Cash Flow Derivative Hedges | Foreign Currency Forwards And Options | Cost Of Sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) recognized in other comprehensive income (loss)			0
Cash Flow Derivative Hedges | Foreign Currency Forwards And Options | Selling, General and Administrative Expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) recognized in other comprehensive income (loss)	$ (535)	$ 719	$ (5,360)	$ (97)

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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4D
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624177-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959

+ Details

Name:	us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=118930883&loc=d3e637-108580

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109978405&loc=d3e80720-113993

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580

+ Details

Name:	us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax
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_IncomeStatementLocationAxis=us-gaap_SellingGeneralAndAdministrativeExpensesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
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:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=tg_ForeignCurrencyForwwardsAndOptionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: