Debt Instrument Issuance Price Percentage

No definition available.

Name:	gff_DebtInstrumentIssuancePricePercentage
Namespace Prefix:	gff_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Number Of Interest Rate Step-downs

+ References

No definition available.

+ Details

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Namespace Prefix:	gff_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Quarterly Principal Payment, Percentage

+ References

No definition available.

+ Details

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Namespace Prefix:	gff_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Secured Overnight Financing Rate Floor, Percentage

+ References

No definition available.

+ Details

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Namespace Prefix:	gff_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Lessee, Finance Lease, Buyout Amount

+ References

No definition available.

+ Details

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Namespace Prefix:	gff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Lessee, Finance Lease, Number Of Options to Extend

+ References

No definition available.

+ Details

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Namespace Prefix:	gff_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Line Of Credit Facility, Maximum Borrowing Capacity, Canceled

+ References

No definition available.

+ Details

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Namespace Prefix:	gff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line of Credit Facility, Maximum Borrowing Capacity, Accordion Feature

+ References

No definition available.

+ Details

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Namespace Prefix:	gff_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum percentage of equity interest of subsidiaries borrowings guaranteed.

+ References

No definition available.

+ Details

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Namespace Prefix:	gff_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- 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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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- 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.

+ References

+ Details

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

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Balance Type:	credit
Period Type:	instant

- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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+ 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.

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- Definition

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

+ References

+ Details

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Period Type:	instant

- 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.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Amount of the required periodic payments applied to principal.

+ References

+ Details

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Balance Type:	debit
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Period Type:	instant

- Definition

Discount rate used by lessee to determine present value of finance lease payments.

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- Definition

Term of lessee's finance lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Period Type:	instant

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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- Definition

The effective interest rate at the end of the reporting period.

+ References

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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- Definition

The carrying value as of the balance sheet date of the noncurrent portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

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- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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LONG-TERM DEBT - Narrative (Details) $ in Thousands			1 Months Ended			3 Months Ended	6 Months Ended	12 Months Ended
LONG-TERM DEBT - Narrative (Details) $ in Thousands	Jan. 24, 2022 USD ($) step_down	Dec. 31, 2021	Jul. 31, 2018 GBP (£)	Jul. 31, 2016 AUD ($)	Nov. 30, 2012	Mar. 31, 2022 AUD ($)	Mar. 31, 2022 USD ($) option	Dec. 31, 2020 USD ($)	Mar. 31, 2022 CAD ($)	Mar. 31, 2022 AUD ($)	Mar. 31, 2022 GBP (£)	Dec. 09, 2021 USD ($)	Sep. 30, 2021 USD ($)	Dec. 30, 2020 USD ($)	Aug. 03, 2020 USD ($)	Jun. 22, 2020
Debt Instrument [Line Items]
Debt outstanding							$ 1,997,555,000						$ 1,060,506,000
Basis spread on variable rate					1.30%
Long-term debt							$ 1,966,835,000						$ 1,045,683,000
Ocala, Florida
Debt Instrument [Line Items]
Lessee, finance Lease, discount rate							5.60%		5.60%	5.60%	5.60%
Number of option to extend \| option							2
Lease renewal term							5 years		5 years	5 years	5 years
Troy, Ohio
Debt Instrument [Line Items]
Lessee, finance Lease, discount rate							5.00%		5.00%	5.00%	5.00%
Lessee, finance lease buyout amount							$ 1
Term Loan \| Northcote Holdings Pty. Ltd
Debt Instrument [Line Items]
Repayments of debt						$ 9,625,000
Long-term debt										$ 18,375,000
Term Loan \| Ames UK
Debt Instrument [Line Items]
Face amount \| £			£ 14,000,000
Debt instrument, periodic payment, principal \| £			438,000
Periodic payment terms, balloon payment to be paid \| £			£ 7,088,000
Revolver due 2025
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 400,000
Maximum borrowing capacity, accordion feature												$ 100,000,000
Maximum percentage of equity interest of subsidiaries borrowings guaranteed							65.00%
Outstanding standby letters of credit							$ 13,815,000
Remaining borrowing capacity							$ 233,039,000
Revolver due 2025 \| Secured Overnight Financing Rate
Debt Instrument [Line Items]
Basis spread on variable rate							2.00%
Revolver due 2025 \| Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate							1.00%
Revolver due 2025 \| SONIA
Debt Instrument [Line Items]
Basis spread on variable rate							2.00%
Mortgages \| SONIA \| Ames UK
Debt Instrument [Line Items]
Basis spread on variable rate			1.92%
Revolving Credit Facility \| Northcote Holdings Pty. Ltd
Debt Instrument [Line Items]
Maximum borrowing capacity				$ 20,000,000
Line of credit facility, cancelled										$ 20,000,000
Revolving Credit Facility \| Ames UK
Debt Instrument [Line Items]
Face amount \| £			£ 5,000,000
Long-term debt							$ 3,713,000				£ 2,827,000
Long-term line of credit, revolver outstanding balance							0
Revolving Credit Facility \| SONIA \| Ames UK
Debt Instrument [Line Items]
Basis spread on variable rate		4.00%	3.25%
Term and Mortgage Loans \| Ames UK
Debt Instrument [Line Items]
Long-term debt							$ 15,948,000				12,145,000
Trade Loan Facility \| Ames UK
Debt Instrument [Line Items]
Face amount \| £											8,500,000
Debt instrument, term							135 days
Short-term debt \| £											£ 8,000,000
Trade Loan Facility \| Federal Target Range \| Ames UK \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate							2.50%
Trade Loan Facility \| Federal Target Range \| Ames UK \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate							2.88%
Letter of Credit Subfacility \| Revolver due 2025
Debt Instrument [Line Items]
Maximum borrowing capacity												100,000,000
Multicurrency Subfacility \| Revolver due 2025
Debt Instrument [Line Items]
Maximum borrowing capacity												$ 200,000,000
Receivables Purchase Facility \| Northcote Holdings Pty. Ltd
Debt Instrument [Line Items]
Debt instrument, interest rate, effective percentage							1.31%		1.31%	1.31%	1.31%
Maximum borrowing capacity										$ 15,000,000
Remaining borrowing capacity							$ 11,273,000			$ 15,000,000
Long-term line of credit							$ 0
Receivables Purchase Facility \| Bank Bill Sap Rate \| Northcote Holdings Pty. Ltd
Debt Instrument [Line Items]
Basis spread on variable rate				1.25%
Senior notes due 2028
Debt Instrument [Line Items]
Face amount														$ 1,000,000,000
Debt instrument, interest rate, stated percentage							5.75%		5.75%	5.75%	5.75%		5.75%			5.75%
Debt outstanding							$ 1,000,000,000						$ 1,000,000,000
Capitalized debt issuance costs															$ 16,448,000
Debt issuance fees and expenses, net							12,257,000
Long-term debt							988,033,000						987,022,000
Senior notes due 2028 \| Fair Value, Inputs, Level 1
Debt Instrument [Line Items]
Senior note, fair value disclosure							945,000,000
Senior notes due 2022
Debt Instrument [Line Items]
Repayments of debt								$ 1,000,000,000
Debt instrument, interest rate, stated percentage																5.25%
Senior Notes
Debt Instrument [Line Items]
Debt outstanding							1,000,000,000
Non US lines of credit
Debt Instrument [Line Items]
Debt outstanding							11,713,000						3,012,000
Maximum borrowing capacity							12,018,000		$ 15,000
Long-term debt							$ 11,704,000						2,995,000
Non US lines of credit \| Bankers Acceptance Rate
Debt Instrument [Line Items]
Interest rate at period end							2.38%		2.38%	2.38%	2.38%
Non US lines of credit \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Interest rate at period end							1.75%		1.75%	1.75%	1.75%
Mortgages \| Ames UK
Debt Instrument [Line Items]
Face amount \| £			£ 4,000,000
Interest rate at period end							2.61%		2.61%	2.61%	2.61%
Debt instrument, periodic payment, principal \| £			105,000
Periodic payment terms, balloon payment to be paid \| £			£ 2,349,000
Term Loan \| Term Loan B 2029
Debt Instrument [Line Items]
Face amount	800,000,000
Capitalized debt issuance costs	$ 15,466,000
Debt issuance fees and expenses, net							$ 15,235,000
Secured overnight financing rate floor	0.00005%
Debt instrument, interest rate, effective percentage	0.00033%
Debt instrument, issuance price (in percentage)	99.75%
Debt instrument, number of interest rate step-downs \| step_down	2
Debt instrument, quarterly principal payment, percentage	0.25%
Debt instrument, term	7 years
Term Loan \| Term Loan B 2029 \| Secured Overnight Financing Rate
Debt Instrument [Line Items]
Basis spread on variable rate	0.00028%
Term Loan B 2029
Debt Instrument [Line Items]
Debt outstanding							800,000,000						0
Long-term debt							782,795,000						$ 0
Term Loan B 2029 \| Fair Value, Inputs, Level 1
Debt Instrument [Line Items]
Senior note, fair value disclosure							$ 792,000,000