XML 81 R71.htm IDEA: XBRL DOCUMENT v3.21.4

Related Party Transactions - Additional Information (Detail) - Axis LLC - USD ($) $ in Millions	3 Months Ended
	Nov. 30, 2021	Nov. 30, 2020
Related Party Transaction [Line Items]
Percentage of ownership in entity	41.90%
Railcar Components
Related Party Transaction [Line Items]
Purchases of goods from related party	$ 2.8	$ 3.8

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 http://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:	us-gaap_RelatedPartyTransactionAxis=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: