XML 79 R71.htm IDEA: XBRL DOCUMENT
v3.25.1

Leases - Additional Information (Detail) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Feb. 28, 2025 | Feb. 29, 2024 | Feb. 28, 2025 | Feb. 29, 2024 | Aug. 31, 2024
Lessor and Lessee, Lease, Description [Line Items] |  |  |  |  |
Operating lease option to extend |  |  | options to extend up to 8 years |  |
Leasing & Management Services |  |  |  |  |
Lessor and Lessee, Lease, Description [Line Items] |  |  |  |  |
Operating lease rental revenues | $ 35.6 | $ 30.5 | $ 67.6 | $ 58.1 |
Operating Lease, Lease Income, Statement of Income or Comprehensive Income [Extensible Enumeration] | Revenue from Contract with Customer, Excluding Assessed Tax | Revenue from Contract with Customer, Excluding Assessed Tax | Revenue from Contract with Customer, Excluding Assessed Tax | Revenue from Contract with Customer, Excluding Assessed Tax |
Car Hire Utilization Arrangements |  |  |  |  |
Lessor and Lessee, Lease, Description [Line Items] |  |  |  |  |
Operating lease rental revenues | $ 6.2 | $ 5.1 | $ 10.5 | $ 10.5 |
Minimum |  |  |  |  |
Lessor and Lessee, Lease, Description [Line Items] |  |  |  |  |
Sublease period |  |  | 1 year |  |
Opreating lease remaining lease term |  |  | 1 year |  |
Maximum |  |  |  |  |
Lessor and Lessee, Lease, Description [Line Items] |  |  |  |  |
Sublease period |  |  | 11 years |  |
Opreating lease remaining lease term |  |  | 74 years |  |
Equipment on Operating Lease |  |  |  |  |
Lessor and Lessee, Lease, Description [Line Items] |  |  |  |  |
Accumulated depreciation | 107.2 |  | $ 107.2 |  | $ 93.4
Depreciation expense | $ 9.5 | $ 8.4 | $ 18.1 | $ 16.2 |

X
- Definition Lessor and lessee lease, description. + References No definition available. + Details
Name: | gbx_LessorAndLesseeLeaseDescriptionLineItems
Namespace Prefix: | gbx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Operating Lease Remaining Lease Term. + References No definition available. + Details
Name: | gbx_OperatingLeaseRemainingLeaseTerm
Namespace Prefix: | gbx_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Sublease period. + References No definition available. + Details
Name: | gbx_SubleasePeriod
Namespace Prefix: | gbx_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(8)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(14)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482099/360-10-50-1 + Details
Name: | us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-28 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482099/360-10-50-1 + Details
Name: | us-gaap_Depreciation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Description of terms and conditions of option to extend lessee's operating lease. Includes, but is not limited to, information about option recognized as part of right-of-use asset and lease liability. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478964/842-20-50-3 + Details
Name: | us-gaap_LesseeOperatingLeaseOptionToExtend
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Indicates line item in statement of income or comprehensive income that includes operating lease income. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479016/842-30-45-3 + Details
Name: | us-gaap_OperatingLeaseIncomeComprehensiveIncomeExtensibleList
Namespace Prefix: | us-gaap_
Data Type: | enum2:enumerationSetItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of operating lease income from lease payments and variable lease payments paid and payable to lessor. Includes, but is not limited to, variable lease payments not included in measurement of lease receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479773/842-30-50-5 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 270 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6A -Publisher FASB -URI https://asc.fasb.org/1943274/2147482964/270-10-50-6A Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479016/842-30-45-3 + Details
Name: | us-gaap_OperatingLeaseLeaseIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=gbx_LeasingAndManagementServicesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=gbx_EquipmentOnOperatingLeasesToOtherPartyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |