XML 86 R67.htm IDEA: XBRL DOCUMENT
v3.22.4

Financial Instruments (Narrative) (Details) lb in Millions, $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2022 USD ($) lb | Dec. 31, 2021 USD ($) lb
Derivative [Line Items] |  |
Weight of aluminum that hedged future purchase of aluminum to meet fixed-price forward sales contract obligations, lbs | lb | 20.3 | 14.9
Annual Net Costs Mismatch Translation Exposure - Real vs US Dollar | $ 177.0 |
Amounts of unrealized after-tax gains on derivative instruments | (2.0) |
Aluminum Futures Contracts |  |
Derivative [Line Items] |  |
Derivative, Notional Amount, Net | $ 30.7 | $ 22.1

X
- Definition Annual Net Costs Mismatch Translation Exposure - Real vs US Dollar + References No definition available. + Details
Name: | tg_AnnualNetCostsMismatchTranslationExposureRealvsUSDollar
Namespace Prefix: | tg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Derivative, Notional Amount, Net + References No definition available. + Details
Name: | tg_DerivativeNotionalAmountNet
Namespace Prefix: | tg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=121549185&loc=d3e80748-113994 + Details
Name: | us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Nominal mass used to calculate payments on a derivative instrument. + References No definition available. + Details
Name: | us-gaap_DerivativeNonmonetaryNotionalAmountMass
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:massItemType
Balance Type: | na
Period Type: | duration

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