Debt instrument maturity month and year.

No definition available.

Name:	gbx_DebtInstrumentMaturityMonthAndYear
Namespace Prefix:	gbx_
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Balance Type:	na
Period Type:	duration

- Definition

Debt instrument, maturity year.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Debt instrument repayment date.

+ References

No definition available.

+ Details

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Namespace Prefix:	gbx_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instruments additional interest rate per annum.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Aggregate number of common shares reserved for future issuance.

+ References

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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of a written promise to pay a note, initially due after one year or beyond the operating cycle if longer, which can be exchanged for a specified amount of one or more securities (typically common stock), at the option of the issuer or the holder.

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- Definition

The value of the financial instrument(s) that the original debt is being converted into in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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- Definition

The price per share of the conversion feature embedded in the debt instrument.

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- Definition

Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

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- Definition

Latest date when the debt instrument can be converted into equity, in YYYY-MM-DD format.

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- Definition

Minimum percentage of common stock price to conversion price of convertible debt instruments to determine eligibility of conversion.

+ References

No definition available.

+ Details

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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

+ Details

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

+ Details

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in YYYY-MM-DD format.

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- Definition

Amount of the required periodic payments applied to principal.

+ References

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Amount of payment greater than the preceding installment payments to be paid at final maturity date of debt.

+ References

No definition available.

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Description of debt redemption features under terms of the debt agreement.

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End date of debt instrument redemption period, in YYYY-MM-DD format.

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Start date of debt instrument redemption period, in YYYY-MM-DD format.

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Description of the frequency of periodic payments, which may be presented in a variety of ways (for example, monthly, quarterly, annually).

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Description of long-term debt arrangements, which are debt arrangements that originally require full repayment more than twelve months after issuance or greater than the normal operating cycle of the company, if longer, and disclosures pertaining to the underlying arrangements, including repayment terms, conversion features, interest rates, restrictions on assets and activities, debt covenants, and other matters important to users of the financial statements. Types of long-term debt arrangements include borrowing under notes payable, bonds payable, debentures, term loans, and other contractual obligations for payment.

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- Definition

Percentage of an entity's outstanding debt that is designated as a hedged item in cash flow, fair value, or net investment hedge.

+ References

No definition available.

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Notes Payable, Net - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions	1 Months Ended		12 Months Ended
	Nov. 30, 2023	Feb. 28, 2022	Aug. 31, 2024	Feb. 01, 2024	Aug. 31, 2023	Aug. 31, 2022
Debt Instrument [Line Items]
Debt instrument amount outstanding			$ 1,420,900,000		$ 1,329,900,000
2026 Term Loan
Debt Instrument [Line Items]
Debt instrument, maturity month and year			2026-08
Periodic Principal Payment			$ 3,700,000
Balloon payment			$ 222,600,000
Swap agreement interest rate			75.00%
Debt instrument amount outstanding			$ 251,700,000
2026 Term Loan \| SOFR
Debt Instrument [Line Items]
Debt instrument, percentage points added to the reference rate			1.50%
2026 Term Loan \| SOFR Adjustment
Debt Instrument [Line Items]
Debt instrument, percentage points added to the reference rate			0.10%
2027 Term Loan
Debt Instrument [Line Items]
Debt instrument, maturity month and year			2027-08
Periodic Principal Payment			$ 3,100,000
Balloon payment			$ 283,700,000
Swap agreement interest rate			100.00%
Debt instrument amount outstanding			$ 320,500,000
2027 Term Loan \| SOFR
Debt Instrument [Line Items]
Debt instrument, percentage points added to the reference rate			1.625%
2027 Term Loan \| SOFR Adjustment
Debt Instrument [Line Items]
Debt instrument, percentage points added to the reference rate			0.10%
2.875% Convertible senior notes, due 2028
Debt Instrument [Line Items]
Debt instrument, effective interest rate			5.75%
Debt instrument, interest rate			2.875%		2.875%	2.875%
Description of long term debt			Convertible senior notes, due 2028 (2028 Convertible Notes), bear interest at a fixed rate of 2.875%, paid semiannually in arrears on April 15th and October 15th.
Frequency of payments			semiannually
Debt instrument, maturity date			Apr. 15, 2028
Convertible senior notes			$ 373,800,000		$ 373,800,000
Convertible notes initial conversion rate, shares per $1,000 principal amount			0.180317
Debt instrument, convertible, principal amount			$ 1,000
Convertible notes conversion rate, per share			$ 55.46
Number of shares reserved for future issuance			8.2
2.875% Convertible senior notes, due 2028 \| Redemption on or After April 15, 2025
Debt Instrument [Line Items]
Debt instrument, convertible, latest date			Jan. 15, 2028
Debt instrument redemption start date			Apr. 15, 2025
Debt instrument redemption end date			Apr. 15, 2028
Debt instrument, convertible, threshold percentage of stock price trigger			130.00%
Debt instrument redemption description			Additionally, the Company may elect to call the notes on or after April 15, 2025 and on or before the 40th trading day prior to April 15, 2028, at a cash redemption price described in the 2028 Notes Indenture if the stock price exceeds 130% of the conversion price during certain trading days as defined in the 2028 Notes Indenture.
2.875% Convertible senior notes, due 2024
Debt Instrument [Line Items]
Debt instrument, interest rate			2.875%		2.875%	2.875%
Debt instrument, maturity date			Feb. 01, 2024
Convertible senior notes			$ 0	$ 47,700,000	$ 47,700,000
Leasing Nonrecourse Term Loans \| Asset-Backed Term Notes
Debt Instrument [Line Items]
Debt instrument amount outstanding			$ 471,600,000
GBX Leasing Warehouse Facility
Debt Instrument [Line Items]
Swap agreement interest rate			74.00%
GBX Leasing Warehouse Facility \| SOFR Adjustment
Debt Instrument [Line Items]
Debt instrument, percentage points added to the reference rate			0.11%
GBX Leasing Warehouse Facility \| GBXL I Series 2022-1 Notes
Debt Instrument [Line Items]
Debt, Principal amount		$ 323,300,000
Debt instrument, maturity month and year		2022-02
Frequency of payments			monthly
Debt instrument, maturity date			Feb. 20, 2052
Debt instrument, repayment date			Jan. 20, 2029
Debt instrument, maturity year			2052
Debt instruments additional interest rate per annum			4.00%
GBX Leasing Warehouse Facility \| GBXL I Series 2022-1 Notes \| GBXL I Series 2022-1 Class A Secured Railcar Equipment Notes
Debt Instrument [Line Items]
Debt, Principal amount			$ 274,800,000
Debt instrument, interest rate			2.87%
GBX Leasing Warehouse Facility \| GBXL I Series 2022-1 Notes \| GBXL I Series 2022-1 Class B Secured Railcar Equipment Notes
Debt Instrument [Line Items]
Debt, Principal amount			$ 20,700,000
Debt instrument, interest rate			3.45%
GBX Leasing Warehouse Facility \| 2023 GBXL Notes
Debt Instrument [Line Items]
Debt, Principal amount	$ 178,500,000
Debt instrument, maturity month and year	2023-11
Frequency of payments			monthly
Debt instrument, maturity date			Nov. 20, 2053
Debt instrument, repayment date			Nov. 20, 2030
Debt instrument, maturity year			2053
Debt instruments additional interest rate per annum			4.00%
GBX Leasing Warehouse Facility \| 2023 GBXL Notes \| GBXL I Series 2023-1 Class A Secured Railcar Equipment Notes
Debt Instrument [Line Items]
Debt, Principal amount			$ 156,700,000
Debt instrument, interest rate			6.42%
GBX Leasing Warehouse Facility \| 2023 GBXL Notes \| GBXL I Series 2023-1 Class B Secured Railcar Equipment Notes
Debt Instrument [Line Items]
Debt, Principal amount			$ 19,400,000
Debt instrument, interest rate			7.28%