XML 85 R74.htm IDEA: XBRL DOCUMENT
v3.23.1

Related Party Transactions - Additional Information (Detail) - Axis LLC - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Feb. 28, 2023 | Feb. 28, 2022 | Feb. 28, 2023 | Feb. 28, 2022
Related Party Transaction [Line Items] |  |  |  |
Percentage of ownership in entity | 41.90% |  | 41.90% |
Railcar Components |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Purchases of goods from related party | $ 1.8 | $ 3.3 | $ 4.5 | $ 6.1

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI https://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition Purchases during the period (excluding transactions that are eliminated in consolidated or combined financial statements) with related party. + References No definition available. + Details
Name: | us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=gbx_AxisLlcMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=gbx_RailcarComponentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |