Interim Financial Statements	6 Months Ended
Feb. 28, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Interim Financial Statements	Note 1 – Interim Financial Statements The Condensed Consolidated Financial Statements of The Greenbrier Companies, Inc. and its subsidiaries (Greenbrier or the Company) as of February 28, 2021 and for the three and six months ended February 28, 2021 and February 29, 2020 have been prepared to reflect all adjustments (consisting of normal recurring accruals) that, in the opinion of management, are necessary for a fair presentation of the financial position, operating results and cash flows for the periods indicated. The results of operations for the three and six months ended February 28, 2021 are not necessarily indicative of the results to be expected for the entire year ending August 31, 2021. Certain notes and other information have been condensed or omitted from the interim financial statements presented in this Quarterly Report on Form 10-Q. Therefore, these unaudited financial statements should be read in conjunction with the Consolidated Financial Statements contained in the Company’s Annual Report on Form 10-K for the year ended August 31, 2020. Management Estimates – The preparation of financial statements in conformity with accounting principles generally accepted in the U.S. (GAAP) requires judgment on the part of management to arrive at estimates and assumptions on matters that are inherently uncertain. These estimates may affect the amount of assets, liabilities, revenue and expenses reported in the financial statements and accompanying notes and disclosure of contingent assets and liabilities within the financial statements. Estimates and assumptions are periodically evaluated and may be adjusted in future periods. Actual results could differ from those estimates. Reclassifications – Certain immaterial reclassifications have been made to prior year balances in order to conform to the current year’s presentation. Initial Adoption of Accounting Standards Measurement of Credit Losses on Financial Instruments In June 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update 2016-13, Financial Instruments – Credit Losses (ASU 2016-13). This update introduced a new model for recognizing credit losses on financial instruments based on an estimate of current expected credit losses. The new guidance applies to loans, accounts receivable, trade receivables, other financial assets measured at amortized cost, loan commitments and other off-balance sheet credit exposures. The new guidance also applies to debt securities and other financial assets measured at fair value through other comprehensive income (loss). The new guidance is effective for annual reporting periods beginning after December 15, 2019, with early adoption permitted. The Company adopted this guidance beginning September 1, 2020. The Company estimated the expected lifetime credit loss by pooling financial instruments based on similar characteristics. Expected losses were then estimated using historical loss information and aging considerations, as well as other information such as the current and future economic conditions of its customers and the end markets in which they operate. The Company adopted this guidance using a modified retrospective approach through a cumulative effect adjustment, which decreased opening retained earnings by $0.5 million on September 1, 2020. The ongoing application of ASU 2016-13 is not expected to materially impact the Company’s consolidated financial statements. Prospective Accounting Changes Convertible Instruments and Contracts in an Entity’s Own Equity In August 2020, the FASB issued Accounting Standard Update 2020-06, Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity, which simplifies the accounting for certain convertible instruments, amends guidance on derivative scope exceptions for contracts in an entity’s own equity, and modifies the guidance on diluted EPS calculations as a result of these changes. The Company expects this change to reduce reported interest expense, increase reported net income, and result in a reclassification of certain convertible balance sheet amounts from stockholders’ equity to liabilities as it relates to the Company’s convertible senior notes. Additionally, ASU 2020-06 requires the application of the if-converted method to calculate the impact of convertible instruments on diluted EPS, which is expected to be incrementally dilutive compared to the Company’s current accounting treatment. The guidance in this ASU can be adopted using either a full or modified retrospective approach and becomes effective for annual reporting periods beginning after December 15, 2021, with early adoption permitted. The Company is currently evaluating the impact of this standard on its consolidated financial statements and disclosures. Simplification of Accounting for Income Taxes In December 2019, the FASB issued Accounting Standard Update 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic 740 for: recognizing deferred taxes for investments, performing intra-period allocations and calculating taxes in interim periods. The ASU also improves consistent application of GAAP for other areas of Topic 740 by clarifying and amending existing guidance to reduce complexity in certain areas, including recognizing deferred taxes for tax goodwill and allocating taxes to members of a consolidated group. The standard is effective for fiscal years beginning after December 15, 2020. Early adoption is permitted. The Company is currently evaluating the impact of this guidance on its consolidated financial statements and disclosures.

Interim Financial Statements

6 Months Ended

Feb. 28, 2021

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Note 1 – Interim Financial Statements

The Condensed Consolidated Financial Statements of The Greenbrier Companies, Inc. and its subsidiaries (Greenbrier or the Company) as of February 28, 2021 and for the three and six months ended February 28, 2021 and February 29, 2020 have been prepared to reflect all adjustments (consisting of normal recurring accruals) that, in the opinion of management, are necessary for a fair presentation of the financial position, operating results and cash flows for the periods indicated. The results of operations for the three and six months ended February 28, 2021 are not necessarily indicative of the results to be expected for the entire year ending August 31, 2021.

Certain notes and other information have been condensed or omitted from the interim financial statements presented in this Quarterly Report on Form 10-Q. Therefore, these unaudited financial statements should be read in conjunction with the Consolidated Financial Statements contained in the Company’s Annual Report on Form 10-K for the year ended August 31, 2020.

Management Estimates – The preparation of financial statements in conformity with accounting principles generally accepted in the U.S. (GAAP) requires judgment on the part of management to arrive at estimates and assumptions on matters that are inherently uncertain. These estimates may affect the amount of assets, liabilities, revenue and expenses reported in the financial statements and accompanying notes and disclosure of contingent assets and liabilities within the financial statements. Estimates and assumptions are periodically evaluated and may be adjusted in future periods. Actual results could differ from those estimates.

Reclassifications – Certain immaterial reclassifications have been made to prior year balances in order to conform to the current year’s presentation.

Initial Adoption of Accounting Standards

Measurement of Credit Losses on Financial Instruments

In June 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update 2016-13, Financial Instruments – Credit Losses (ASU 2016-13). This update introduced a new model for recognizing credit losses on financial instruments based on an estimate of current expected credit losses. The new guidance applies to loans, accounts receivable, trade receivables, other financial assets measured at amortized cost, loan commitments and other off-balance sheet credit exposures. The new guidance also applies to debt securities and other financial assets measured at fair value through other comprehensive income (loss). The new guidance is effective for annual reporting periods beginning after December 15, 2019, with early adoption permitted. The Company adopted this guidance beginning September 1, 2020. The Company estimated the expected lifetime credit loss by pooling financial instruments based on similar characteristics. Expected losses were then estimated using historical loss information and aging considerations, as well as other information such as the current and future economic conditions of its customers and the end markets in which they operate. The Company adopted this guidance using a modified retrospective approach through a cumulative effect adjustment, which decreased opening retained earnings by $0.5 million on September 1, 2020. The ongoing application of ASU 2016-13 is not expected to materially impact the Company’s consolidated financial statements.

Prospective Accounting Changes

Convertible Instruments and Contracts in an Entity’s Own Equity

In August 2020, the FASB issued Accounting Standard Update 2020-06, Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity, which simplifies the accounting for certain convertible instruments, amends guidance on derivative scope exceptions for contracts in an entity’s own equity, and modifies the guidance on diluted EPS calculations as a result of these changes. The Company expects this change to reduce reported interest expense, increase reported net income, and result in a reclassification of certain convertible balance sheet amounts from stockholders’ equity to liabilities as it relates to the Company’s convertible senior notes. Additionally, ASU 2020-06 requires the application of the if-converted method to calculate the impact of convertible instruments on diluted EPS,

which is expected to be incrementally dilutive compared to the Company’s current accounting treatment. The guidance in this ASU can be adopted using either a full or modified retrospective approach and becomes effective for annual reporting periods beginning after December 15, 2021, with early adoption permitted. The Company is currently evaluating the impact of this standard on its consolidated financial statements and disclosures.

Simplification of Accounting for Income Taxes

In December 2019, the FASB issued Accounting Standard Update 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic 740 for: recognizing deferred taxes for investments, performing intra-period allocations and calculating taxes in interim periods. The ASU also improves consistent application of GAAP for other areas of Topic 740 by clarifying and amending existing guidance to reduce complexity in certain areas, including recognizing deferred taxes for tax goodwill and allocating taxes to members of a consolidated group. The standard is effective for fiscal years beginning after December 15, 2020. Early adoption is permitted. The Company is currently evaluating the impact of this guidance on its consolidated financial statements and disclosures.