XML 73 R61.htm IDEA: XBRL DOCUMENT
v3.21.2

Derivative Instruments - Effect of Derivative Instruments on Statements of Income (Detail) - Cash Flow Hedging - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
May 31, 2021 | May 31, 2020 | May 31, 2021 | May 31, 2020
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) recognized in OCI on derivatives | $ 252 | $ (7,769) | $ (498) | $ (9,973)
Gain (loss) reclassified from accumulated OCI into income | (1,853) | (2,494) | (5,119) | (3,131)
Gain (loss) recognized on derivative (amount excluded from effectiveness testing) | 197 | 549 | 564 | 1,255
Foreign Exchange Forward | Interest and Foreign Exchange |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) recognized in income on derivatives | 95 | 154 | (37) | 60
Foreign Exchange Forward | Sales |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) recognized in OCI on derivatives | 494 | (599) | (1,118) | 164
Gain (loss) reclassified from accumulated OCI into income | (522) | (485) | (1,145) | (584)
Gain (loss) recognized on derivative (amount excluded from effectiveness testing) | 165 | 138 | 467 | 781
Foreign Exchange Forward | Cost Of Revenue |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) recognized in OCI on derivatives | 273 | (2,015) | (22) | (2,198)
Gain (loss) reclassified from accumulated OCI into income | (24) | (1,226) | (73) | (1,228)
Gain (loss) recognized on derivative (amount excluded from effectiveness testing) | 32 | 130 | 97 | 474
Interest rate swap contracts | Interest and Foreign Exchange |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Gain (loss) recognized in OCI on derivatives | (515) | (5,155) | 642 | (7,939)
Gain (loss) reclassified from accumulated OCI into income | $ (1,307) | (783) | $ (3,901) | $ (1,319)
Gain (loss) recognized on derivative (amount excluded from effectiveness testing) |  | $ 281 |  |

X
- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5618551-113959 + Details
Name: | us-gaap_DerivativeGainLossOnDerivativeNet
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_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=121590274&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=121590274&loc=SL5624171-113959 + Details
Name: | us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5624171-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 25 -Section 50 -Paragraph 1 -Subparagraph (a)(1),(2) -URI http://asc.fasb.org/extlink&oid=121577467&loc=d3e76258-113986 + Details
Name: | us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, before tax and reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 20 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=121577181&loc=SL110061190-113977 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5618551-113959 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5624171-113959 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e637-108580 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669646-108580 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

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

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