Commitments and Contingencies	12 Months Ended
Aug. 31, 2025
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 20 — Commitments and Contingencies Portland Harbor Superfund Site The Company’s former Portland, Oregon manufacturing facility (Portland Property) is located adjacent to the Willamette River. In December 2000, the U.S. Environmental Protection Agency (EPA) classified portions of the Willamette River bed and certain riverbanks known as the Portland Harbor, including the portion fronting the Portland Property, as a federal "National Priority List" or "Superfund" site due to sediment contamination (Portland Harbor Superfund Site). The Company and more than 140 other parties have received a "General Notice" of potential liability from the EPA relating to the Portland Harbor Superfund Site. The letter advised the Company that it may be liable for the costs of investigation and remediation (which liability may be joint and several with other potentially responsible parties) as well as for natural resource damages resulting from releases of hazardous substances to the site. Ten private and public entities, including the Company (the Lower Willamette Group or LWG), signed an Administrative Order on Consent (AOC) to perform a remedial investigation/feasibility study (RI/FS) of the Portland Harbor Superfund Site under EPA oversight, and several additional entities did not sign such consent, but nevertheless contributed financially to the effort. The EPA-mandated RI/FS was produced by the LWG and cost over $110 million during a 17-year period. The Company bore a percentage of the total costs incurred by the LWG in connection with the investigation. The Company’s aggregate expenditure during the 17-year period was not material. Some or all of any such outlay may be recoverable from other responsible parties. The EPA issued its Record of Decision (ROD) for the Portland Harbor Superfund Site on January 6, 2017 and accordingly on October 26, 2017, the AOC was terminated. The EPA's January 6, 2017 ROD identifies a cleanup remedy that the EPA estimates will take 13 years of active remediation, followed by 30 years of monitoring with an estimated undiscounted cost of $1.7 billion. The EPA typically expects its cost estimates to be accurate within a range of -30% to +50%, but this ROD states that changes in costs are likely to occur. The ROD does not address responsibility for the costs of remedial action, nor does it allocate such costs among the potentially responsible parties. The EPA has identified several work areas within the ROD remedial action area. One of the units, currently referred to as the river mile 9 West work area (RM9W) includes river sediments offshore and downstream of the Portland Property. It also includes a large portion of the Portland Property's riverbanks. The ROD does not break down total remediation costs by work area. The EPA requested that potentially responsible parties enter AOCs during 2019 agreeing to conduct remedial design studies. Some parties have signed AOCs, including one party with respect to RM9W. Additionally, at some portions of the Portland Harbor Superfund Site, the EPA is conducting the remedial design work. Remedial action will follow remedial design. The Company has not signed an AOC in connection with remedial design, but is assisting in funding a portion of the RM9W remedial design. Separate from the process described above, which focused on the type of remediation to be performed at the Portland Harbor Superfund Site and the schedule for such remediation, approximately 100 parties, including the State of Oregon and the federal government, are participating in a non-judicial, mediated allocation process to try to allocate costs associated with remediation of the Portland Harbor Superfund Site. The Company will continue to participate in the allocation process. Approximately 100 additional parties signed tolling agreements related to such allocations. On April 23, 2009, the Company and the other AOC signatories filed suit against 69 other parties due to a possible limitations period for some such claims. Arkema Inc. et al v. A & C Foundry Products, Inc. et al, U.S. District Court for the District of Oregon, Case #3:09-cv-453-PK. All but 12 of these parties elected to sign tolling agreements and be dismissed without prejudice, and the case has been stayed by the court to allow the allocation to proceed, currently through January 14, 2028. On January 30, 2017, the Confederated Tribes and Bands of the Yakama Nation sued 30 parties, including the Company as well as the federal government and the State of Oregon, for costs it incurred in assessing alleged natural resource damages to the Lower Columbia River and Multnomah Channel from contaminants deposited at the Portland Harbor Superfund Site. Confederated Tribes and Bands of the Yakama Nation v. Air Liquide America Corp., et al., U.S. District Court for the District of Oregon, Portland Division, Case No. 3:17-CV-00164. The complaint does not specify the amount of damages the plaintiff will seek. The Yakama litigation is stayed pending completion of the allocation process under supervision of the Arkema court, currently through January 14, 2028. On November 20, 2024, the Company, as part of a group of about 60 recipients, received a “Special Notice” letter (SNL) from the EPA. The Company timely responded by the May 30, 2025 response deadline. The EPA routinely sends SNLs when it is ready to formally start negotiations with potentially responsible parties in an effort to reach a settlement to conduct or finance the remedial action. Such letters trigger the start of an enforcement moratorium during which time the EPA agrees not to unilaterally order any potentially responsible parties to conduct the remediation. Under this process, if settlement is reached, the settlement terms will normally be set out in a consent decree that is lodged in federal court. The terms of the SNL that the Company received are settlement confidential. The EPA has publicly stated that it issued the letters now because it wants a seamless transition from the remedial-design phase to the remediation-implementation phase, that more potentially responsible parties may receive such a letter, and that the agency expects the settlement negotiations to take up to two years. Some allocation participants, including the Company, are discussing remedial action consent decree terms with the EPA and the U.S. Department of Justice. Responsibility for funding and implementing the EPA's selected cleanup remedy will be determined at an unspecified later date as part of the allocation process. Based on the investigation to date, the Company believes that it did not contribute in any material way to contaminants of concern in the river sediments or the damage of natural resources in the Portland Harbor Superfund Site and that the damage in the area of the Portland Harbor Superfund Site adjacent to the Portland Property precedes the Company’s ownership of the Portland Property. Because these environmental investigations are still underway, sufficient information is currently not available to determine the Company’s liability, if any, for the cost of any required remediation or restoration of the Portland Harbor Superfund Site or to estimate a range of potential loss. Based on the results of the pending investigations and future assessments of natural resource damages, the Company may be required to incur costs associated with additional phases of investigation or remedial action, and may be liable for damages to natural resources. On June 9, 2025, the natural resources trustees for the Portland Harbor Superfund Site, consisting of the U.S., on behalf of the National Oceanic and Atmospheric Administration of the U.S. Department of Commerce and the U.S. Department of the Interior; the State of Oregon, on behalf of the Oregon Department of Fish and Wildlife; and several tribes moved to enter two consent decrees that were lodged with the Oregon district court on November 1, 2023 to resolve trustees’ natural resources claims in a complaint filed on the same day. United States of America et al. v ACF Industries LLC et al., U.S. District Court for the District of Oregon, Case #3:23-cv-01603-YY. The Company is not a defendant under the 2023 complaint nor a party to either of the consent decrees. The consent decrees would resolve the defendants’ liability for natural resource damages at the Portland Harbor Superfund Site before the conclusion of the remedial design and allocation processes. On July 28, 2025, the Company, along with several other potentially responsible parties at the Portland Harbor Superfund Site, filed motions to intervene and to oppose the entry of the consent decrees. The court has granted the motions to intervene. Oral argument was held on September 29, 2025. The court has not yet issued an opinion. Oregon Department of Environmental Quality (DEQ) Regulation of Portland Property The Company entered into a Voluntary Cleanup Agreement with the Oregon Department of Environmental Quality (DEQ) in which the Company agreed to conduct an investigation of whether, and to what extent, past or present operations at the Portland Property may have released hazardous substances into the environment. The Company has also signed an Order on Consent with the DEQ to finalize the investigation of potential onsite sources of contamination that may have a release pathway to the Willamette River. The Company’s aggregate expenditure has not been material, however it could incur significant expenses for remediation. Some or all of any such outlay may be recoverable from other responsible parties. Sale of Portland Property The Company sold the Portland Property in May 2023, but remains potentially liable with respect to the above matters. Any of these matters could adversely affect the Company's business and Consolidated Financial Statements. However, any contamination or exacerbation of contamination that occurs after the sale of the Portland Property will be the liability of the current and future owners and operators of the Portland Property. Other Litigation, Commitments and Contingencies From time to time, Greenbrier is involved as a defendant in litigation in the ordinary course of business, the outcomes of which cannot be predicted with certainty. While the ultimate outcome of such legal proceedings cannot be determined at this time, the Company believes that the resolution of pending litigation will not have a material adverse effect on the Company's Consolidated Financial Statements. As of August 31, 2025, the Company had outstanding letters of credit aggregating to $5.4 million associated with performance guarantees, facility leases and workers compensation insurance.

Commitments and Contingencies

12 Months Ended

Aug. 31, 2025

Commitments and Contingencies Disclosure [Abstract]

Note 20 — Commitments and Contingencies

Portland Harbor Superfund Site

The Company’s former Portland, Oregon manufacturing facility (Portland Property) is located adjacent to the Willamette River. In December 2000, the U.S. Environmental Protection Agency (EPA) classified portions of the Willamette River bed and certain riverbanks known as the Portland Harbor, including the portion fronting the Portland Property, as a federal "National Priority List" or "Superfund" site due to sediment contamination (Portland Harbor Superfund Site). The Company and more than 140 other parties have received a "General Notice" of potential liability from the EPA relating to the Portland Harbor Superfund Site. The letter advised the Company that it may be liable for the costs of investigation and remediation (which liability may be joint and several with other potentially responsible parties) as well as for natural resource damages resulting from releases of hazardous substances to the site. Ten private and public entities, including the Company (the Lower Willamette Group or LWG), signed an Administrative Order

on Consent (AOC) to perform a remedial investigation/feasibility study (RI/FS) of the Portland Harbor Superfund Site under EPA oversight, and several additional entities did not sign such consent, but nevertheless contributed financially to the effort. The EPA-mandated RI/FS was produced by the LWG and cost over $110 million during a 17-year period. The Company bore a percentage of the total costs incurred by the LWG in connection with the investigation. The Company’s aggregate expenditure during the 17-year period was not material. Some or all of any such outlay may be recoverable from other responsible parties. The EPA issued its Record of Decision (ROD) for the Portland Harbor Superfund Site on January 6, 2017 and accordingly on October 26, 2017, the AOC was terminated.

The EPA's January 6, 2017 ROD identifies a cleanup remedy that the EPA estimates will take 13 years of active remediation, followed by 30 years of monitoring with an estimated undiscounted cost of $1.7 billion. The EPA typically expects its cost estimates to be accurate within a range of -30% to +50%, but this ROD states that changes in costs are likely to occur. The ROD does not address responsibility for the costs of remedial action, nor does it allocate such costs among the potentially responsible parties. The EPA has identified several work areas within the ROD remedial action area. One of the units, currently referred to as the river mile 9 West work area (RM9W) includes river sediments offshore and downstream of the Portland Property. It also includes a large portion of the Portland Property's riverbanks. The ROD does not break down total remediation costs by work area. The EPA requested that potentially responsible parties enter AOCs during 2019 agreeing to conduct remedial design studies. Some parties have signed AOCs, including one party with respect to RM9W. Additionally, at some portions of the Portland Harbor Superfund Site, the EPA is conducting the remedial design work. Remedial action will follow remedial design. The Company has not signed an AOC in connection with remedial design, but is assisting in funding a portion of the RM9W remedial design.

Separate from the process described above, which focused on the type of remediation to be performed at the Portland Harbor Superfund Site and the schedule for such remediation, approximately 100 parties, including the State of Oregon and the federal government, are participating in a non-judicial, mediated allocation process to try to allocate costs associated with remediation of the Portland Harbor Superfund Site. The Company will continue to participate in the allocation process. Approximately 100 additional parties signed tolling agreements related to such allocations. On April 23, 2009, the Company and the other AOC signatories filed suit against 69 other parties due to a possible limitations period for some such claims. Arkema Inc. et al v. A & C Foundry Products, Inc. et al, U.S. District Court for the District of Oregon, Case #3:09-cv-453-PK. All but 12 of these parties elected to sign tolling agreements and be dismissed without prejudice, and the case has been stayed by the court to allow the allocation to proceed, currently through January 14, 2028.

On January 30, 2017, the Confederated Tribes and Bands of the Yakama Nation sued 30 parties, including the Company as well as the federal government and the State of Oregon, for costs it incurred in assessing alleged natural resource damages to the Lower Columbia River and Multnomah Channel from contaminants deposited at the Portland Harbor Superfund Site. Confederated Tribes and Bands of the Yakama Nation v. Air Liquide America Corp., et al., U.S. District Court for the District of Oregon, Portland Division, Case No. 3:17-CV-00164. The complaint does not specify the amount of damages the plaintiff will seek. The Yakama litigation is stayed pending completion of the allocation process under supervision of the Arkema court, currently through January 14, 2028.

On November 20, 2024, the Company, as part of a group of about 60 recipients, received a “Special Notice” letter (SNL) from the EPA. The Company timely responded by the May 30, 2025 response deadline. The EPA routinely sends SNLs when it is ready to formally start negotiations with potentially responsible parties in an effort to reach a settlement to conduct or finance the remedial action. Such letters trigger the start of an enforcement moratorium during which time the EPA agrees not to unilaterally order any potentially responsible parties to conduct the remediation. Under this process, if settlement is reached, the settlement terms will normally be set out in a consent decree that is lodged in federal court. The terms of the SNL that the Company received are settlement confidential. The EPA has publicly stated that it issued the letters now because it wants a seamless transition from the remedial-design phase to the remediation-implementation phase, that more potentially responsible parties may receive such a letter, and that the agency expects the settlement negotiations to take up to two years. Some allocation participants, including the Company, are discussing remedial action consent decree terms with the EPA and the U.S. Department of Justice.

Responsibility for funding and implementing the EPA's selected cleanup remedy will be determined at an unspecified later date as part of the allocation process. Based on the investigation to date, the Company believes that it did not contribute in any material way to contaminants of concern in the river sediments or the damage of natural resources

in the Portland Harbor Superfund Site and that the damage in the area of the Portland Harbor Superfund Site adjacent to the Portland Property precedes the Company’s ownership of the Portland Property. Because these environmental investigations are still underway, sufficient information is currently not available to determine the Company’s liability, if any, for the cost of any required remediation or restoration of the Portland Harbor Superfund Site or to estimate a range of potential loss. Based on the results of the pending investigations and future assessments of natural resource damages, the Company may be required to incur costs associated with additional phases of investigation or remedial action, and may be liable for damages to natural resources.

On June 9, 2025, the natural resources trustees for the Portland Harbor Superfund Site, consisting of the U.S., on behalf of the National Oceanic and Atmospheric Administration of the U.S. Department of Commerce and the U.S. Department of the Interior; the State of Oregon, on behalf of the Oregon Department of Fish and Wildlife; and several tribes moved to enter two consent decrees that were lodged with the Oregon district court on November 1, 2023 to resolve trustees’ natural resources claims in a complaint filed on the same day. United States of America et al. v ACF Industries LLC et al., U.S. District Court for the District of Oregon, Case #3:23-cv-01603-YY. The Company is not a defendant under the 2023 complaint nor a party to either of the consent decrees. The consent decrees would resolve the defendants’ liability for natural resource damages at the Portland Harbor Superfund Site before the conclusion of the remedial design and allocation processes. On July 28, 2025, the Company, along with several other potentially responsible parties at the Portland Harbor Superfund Site, filed motions to intervene and to oppose the entry of the consent decrees. The court has granted the motions to intervene. Oral argument was held on September 29, 2025. The court has not yet issued an opinion.

Oregon Department of Environmental Quality (DEQ) Regulation of Portland Property

The Company entered into a Voluntary Cleanup Agreement with the Oregon Department of Environmental Quality (DEQ) in which the Company agreed to conduct an investigation of whether, and to what extent, past or present operations at the Portland Property may have released hazardous substances into the environment. The Company has also signed an Order on Consent with the DEQ to finalize the investigation of potential onsite sources of contamination that may have a release pathway to the Willamette River. The Company’s aggregate expenditure has not been material, however it could incur significant expenses for remediation. Some or all of any such outlay may be recoverable from other responsible parties.

Sale of Portland Property

The Company sold the Portland Property in May 2023, but remains potentially liable with respect to the above matters. Any of these matters could adversely affect the Company's business and Consolidated Financial Statements. However, any contamination or exacerbation of contamination that occurs after the sale of the Portland Property will be the liability of the current and future owners and operators of the Portland Property.

Other Litigation, Commitments and Contingencies

From time to time, Greenbrier is involved as a defendant in litigation in the ordinary course of business, the outcomes of which cannot be predicted with certainty. While the ultimate outcome of such legal proceedings cannot be determined at this time, the Company believes that the resolution of pending litigation will not have a material adverse effect on the Company's Consolidated Financial Statements.

As of August 31, 2025, the Company had outstanding letters of credit aggregating to $5.4 million associated with performance guarantees, facility leases and workers compensation insurance.