XML 42 R53.htm IDEA: XBRL DOCUMENT v2.4.1.9
Commitments and Contingencies - Additional Information (Detail) (USD $)
3 Months Ended 0 Months Ended 1 Months Ended
Nov. 30, 2014
Jul. 18, 2014
Nov. 30, 2014
Aug. 31, 2014
Commitments and Contingencies Disclosure [Line Items]        
Remedial investigation and feasibility study $ 110,000,000gbx_FeasibilityAndEvaluationCosts      
Remedial investigation and feasibility study, period 14 years      
Remedial investigation and feasibility study, expiration year 2017      
Bank and third party warranty and performance guarantee facilities 4,800,000gbx_WarrantLiabilitiesCurrent   4,800,000gbx_WarrantLiabilitiesCurrent  
Performance Guarantee        
Commitments and Contingencies Disclosure [Line Items]        
Outstanding letters of credit 8,600,000us-gaap_LettersOfCreditOutstandingAmount
/ us-gaap_GuaranteeObligationsByNatureAxis
= us-gaap_PerformanceGuaranteeMember
  8,600,000us-gaap_LettersOfCreditOutstandingAmount
/ us-gaap_GuaranteeObligationsByNatureAxis
= us-gaap_PerformanceGuaranteeMember
 
Mexican Joint Venture Credit Facility        
Commitments and Contingencies Disclosure [Line Items]        
Debt outstanding 33,100,000gbx_DebtOutstanding
/ us-gaap_GuaranteeObligationsByNatureAxis
= gbx_MexicanJointVentureCreditFacilityMember
  33,100,000gbx_DebtOutstanding
/ us-gaap_GuaranteeObligationsByNatureAxis
= gbx_MexicanJointVentureCreditFacilityMember
 
Guarantee obligations 29,000,000us-gaap_GuaranteeObligationsMaximumExposure
/ us-gaap_GuaranteeObligationsByNatureAxis
= gbx_MexicanJointVentureCreditFacilityMember
  29,000,000us-gaap_GuaranteeObligationsMaximumExposure
/ us-gaap_GuaranteeObligationsByNatureAxis
= gbx_MexicanJointVentureCreditFacilityMember
 
GBW Railcar Services Holdings, LLC        
Commitments and Contingencies Disclosure [Line Items]        
Equity method investment, percentage of ownership interest   50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= gbx_GbwRailcarServicesHoldingsLlcMember
   
Payment to acquire equity method investments   10,000,000us-gaap_PaymentsToAcquireEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= gbx_GbwRailcarServicesHoldingsLlcMember
2,500,000us-gaap_PaymentsToAcquireEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= gbx_GbwRailcarServicesHoldingsLlcMember
2,500,000us-gaap_PaymentsToAcquireEquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= gbx_GbwRailcarServicesHoldingsLlcMember
Account receivable 21,000,000us-gaap_AccountsReceivableGross
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= gbx_GbwRailcarServicesHoldingsLlcMember
  21,000,000us-gaap_AccountsReceivableGross
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= gbx_GbwRailcarServicesHoldingsLlcMember
 
GBW Railcar Services Holdings, LLC | Watco Companies LLC        
Commitments and Contingencies Disclosure [Line Items]        
Equity method investment, percentage of ownership interest   50.00%us-gaap_EquityMethodInvestmentOwnershipPercentage
/ dei_LegalEntityAxis
= gbx_WatcoCompaniesLlcMember
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= gbx_GbwRailcarServicesHoldingsLlcMember
   
Minimum        
Commitments and Contingencies Disclosure [Line Items]        
Period for remedial action 2 years      
Maximum        
Commitments and Contingencies Disclosure [Line Items]        
Period for remedial action 28 years      
Portland Harbor Site | Minimum        
Commitments and Contingencies Disclosure [Line Items]        
Cleanup expenses 169,000,000gbx_CostOfEnvironmentalCleanup
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_StatementBusinessSegmentsAxis
= gbx_LocationOneMember
     
Portland Harbor Site | Maximum        
Commitments and Contingencies Disclosure [Line Items]        
Cleanup expenses 1,800,000,000gbx_CostOfEnvironmentalCleanup
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_StatementBusinessSegmentsAxis
= gbx_LocationOneMember
     
Area Of Willamette River Adjacent to the Company's Portland, Oregon Manufacturing Facility | Minimum        
Commitments and Contingencies Disclosure [Line Items]        
Cleanup expenses 9,000,000gbx_CostOfEnvironmentalCleanup
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_StatementBusinessSegmentsAxis
= gbx_LocationTwoMember
     
Area Of Willamette River Adjacent to the Company's Portland, Oregon Manufacturing Facility | Maximum        
Commitments and Contingencies Disclosure [Line Items]        
Cleanup expenses $ 163,000,000gbx_CostOfEnvironmentalCleanup
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_StatementBusinessSegmentsAxis
= gbx_LocationTwoMember