XML 67 R59.htm IDEA: XBRL DOCUMENT
v3.25.1

Earnings Per Share - Reconciliation of Shares Used in Computation of Basic and Diluted Earnings Per Common Share (Detail) - shares shares in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Feb. 28, 2025 | Feb. 29, 2024 | Feb. 28, 2025 | Feb. 29, 2024
Earnings Per Share Disclosure [Line Items] |  |  |  |  |
Weighted average basic common shares outstanding |  | 31,376 | 31,117 | 31,311 | 31,071
Dilutive effect of restricted stock units | [1] | 959 | 890 | 946 | 911
Weighted average diluted common shares outstanding |  | 33,228 | 32,570 | 32,745 | 32,676
2.875% Convertible senior notes, due 2024 |  |  |  |  |
Earnings Per Share Disclosure [Line Items] |  |  |  |  |
Dilutive effect of convertible notes | [2] |  | 563 |  | 694
2.875% Convertible senior notes, due 2028 |  |  |  |  |
Earnings Per Share Disclosure [Line Items] |  |  |  |  |
Dilutive effect of convertible notes | [3] | 893 |  | 488 |
[1] | Restricted stock units and restricted stock units subject to performance criteria, for which actual levels of performance above target have been achieved, are included in weighted average diluted common shares outstanding when the Company is in a net earnings position.
[2] | The dilutive effect of the 2.875% Convertible notes due 2024 was included for the three and six months ended February 29, 2024 under the “if converted” method as further discussed below. These notes were retired on February 1, 2024.
[3] | The dilutive effect of the 2.875% Convertible notes due 2028 was excluded for the three and six months ended February 29, 2024 as the average stock price was less than the applicable conversion price and therefore was considered anti-dilutive. As these notes require cash settlement for the principal, only a premium is potentially dilutive under the "if converted" method as further discussed below.

X
- Definition Earnings Per Share Disclosure [Line Items] + References No definition available. + Details
Name: | gbx_EarningsPerShareDisclosureLineItems
Namespace Prefix: | gbx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of convertible debt securities using the if-converted method. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482662/260-10-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 42 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482689/260-10-45-42 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 40 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482689/260-10-45-40 + Details
Name: | us-gaap_IncrementalCommonSharesAttributableToConversionOfDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480454/718-10-45-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482662/260-10-50-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 22 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482689/260-10-45-22 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 23 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482689/260-10-45-23 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 28A -Publisher FASB -URI https://asc.fasb.org/1943274/2147482689/260-10-45-28A + Details
Name: | us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482662/260-10-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 16 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482689/260-10-45-16 + Details
Name: | us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482662/260-10-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482689/260-10-45-10 + Details
Name: | us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gbx_TwoPointEightSevenFiveConvertibleSeniorNotesDue2024Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=gbx_TwoPointEightSevenFiveConvertibleSeniorNotesDue2028Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |