XML 47 R29.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Derivative Financial Instruments (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2017
Derivatives, Fair Value [Line Items] |
Schedule Of Pretax Effect On Net Income (Loss) And Other Comprehensive Income (Loss) Of Derivative Instruments Classified As Cash Flow Hedges | The effect on net income (loss) and other comprehensive income (loss) of derivative instruments classified as cash flow hedges and described in the previous paragraphs for the three and nine month periods ended September 30, 2017 and 2016 is summarized in the table below:
(In Thousands) | Cash Flow Derivative Hedges
| Aluminum Futures Contracts |  | Foreign Currency Forwards
| Three Months Ended September 30,
| 2017 |  | 2016 |  | 2017 |  | 2016
Amount of pretax gain (loss) recognized in other comprehensive income (loss) | $ | 757 |  |  | $ | (230 | ) |  | $ | — |  |  | $ | — |
Location of gain (loss) reclassified from accumulated other comprehensive income (loss) into net income (loss) (effective portion) | Cost of sales |  |  | Cost of sales |  |  | Cost of sales |  |  | Cost of sales |
Amount of pretax gain (loss) reclassified from accumulated other comprehensive income (loss) to net income (loss) (effective portion) | $ | 231 |  |  | $ | (160 | ) |  | $ | 15 |  |  | $ | 15 |
| Aluminum Futures Contracts |  | Foreign Currency Forwards
| Nine Months Ended September 30,
| 2017 |  | 2016 |  | 2017 |  | 2016
Amount of pre-tax gain (loss) recognized in other comprehensive income (loss) | $ | 1,281 |  |  | $ | (93 | ) |  | $ | — |  |  | $ | — |
Location of gain (loss) reclassified from accumulated other comprehensive income (loss) into net income (loss) (effective portion) | Cost of sales |  |  | Cost of sales |  |  | Cost of sales |  |  | Cost of sales |
Amount of pre-tax gain (loss) reclassified from accumulated other comprehensive income (loss) to net income (loss) (effective portion) | $ | 785 |  |  | $ | (1,669 | ) |  | $ | 46 |  |  | $ | 46 |
Aluminum Futures Contracts |
Derivatives, Fair Value [Line Items] |
Summary Of Location And Fair Value Of Derivative Financial Instruments | The table below summarizes the location and gross amounts of aluminum futures contract fair values in the consolidated balance sheets as of September 30, 2017 and December 31, 2016:
| September 30, 2017 |  | December 31, 2016
(In Thousands) | Balance Sheet Account |  | Fair Value |  | Balance Sheet Account |  | Fair Value
Derivatives Designated as Hedging Instruments |  |  |  |  |  |  |
Asset derivatives: Aluminum futures contracts | Prepaid expenses and other |  | $ | 792 |  |  | Prepaid expenses and other |  | $ | 308 |
Liability derivatives: Aluminum futures contracts | Prepaid expenses and other |  | $ | (25 | ) |  | Prepaid expenses and other |  | $ | (37 | )
Net asset (liability) |  |  | $ | 767 |  |  |  |  | $ | 271 |

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

X
- Definition Tabular disclosure of the effective portion of the gains and losses on derivative instruments designated (and non-derivative instruments) designated and qualifying in cash flow hedges and net investment hedges that was recognized in other comprehensive income (loss) 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
Name: | us-gaap_ScheduleOfDerivativeInstrumentsEffectOnOtherComprehensiveIncomeLossTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the location and fair value amounts of derivative instruments (and nonderivative instruments that are designated and qualify as hedging instruments) reported in the statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624163-113959 + Details
Name: | us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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