COMMITMENTS AND CONTINGENT LIABILITIES	12 Months Ended
COMMITMENTS AND CONTINGENT LIABILITIES	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENT LIABILITIES	COMMITMENTS AND CONTINGENT LIABILITIES Purchase Commitments Purchase obligations are generally for the purchase of goods and services in the ordinary course of business. Griffon uses blanket purchase orders to communicate expected requirements to certain vendors. Purchase obligations reflect those purchase orders where the commitment is considered to be firm. Amounts purchased under such commitments were $255,661, $235,148 and $142,712 for the years ended September 30, 2022, 2021 and 2020, respectively. Aggregate future minimum purchase obligations at September 30, 2022 are $184,422 in 2022, $16,463 in 2023, $3,622 in 2024, $0 in 2025 and $0 in 2026. Legal and environmental Peekskill Site. Lightron Corporation (“Lightron”), a wholly-owned subsidiary of Griffon, once conducted lamp manufacturing and metal finishing operations at a location in the Town of Cortlandt, New York, just outside the city of Peekskill, New York (the “Peekskill Site”) which was owned by ISC Properties, Inc. (“ISCP”), a wholly-owned subsidiary of Griffon, for approximately three years. ISCP sold the Peekskill Site in November 1982. Based upon studies conducted by ISCP and the New York Department of Environmental Conservation, soils and groundwater beneath the Peekskill Site contain chlorinated solvents and metals. Stream sediments downgradient of the Peekskill Site also contain metals. On May 15, 2019 the United States Environmental Protection Agency ("EPA") added the Peekskill Site to the National Priorities List under CERCLA and has since reached agreement with Lightron and ISCP wherein Lightron and ISCP will perform a Remedial Investigation/Feasibility Study (“RI/FS”). Lightron has not engaged in any operations in over three decades. ISCP functioned solely as a real estate holding company and has not held any real property in over three decades. Griffon does not acknowledge any responsibility to perform any investigation or remediation at the Peekskill Site. One of Griffon’s insurers is defending Lightron, ISCP and Griffon subject to a reservation of rights and is paying the costs of the RI/FS. Union Fork and Hoe, Frankfort, NY site. The former Union Fork and Hoe property in Frankfort, NY was acquired by AMES in 2006 as part of a larger acquisition, and has historic site contamination involving chlorinated solvents, petroleum hydrocarbons and metals. AMES entered into an Order on Consent with the New York State Department of Environmental Conservation (“DEC”). While the Order is without admission or finding of liability or acknowledgment that there has been a release of hazardous substances at the site, the Order required AMES to perform a remedial investigation of certain portions of the property and to recommend a remediation option. In 2011, remediation of chlorinated solvents in the groundwater was completed to the satisfaction of DEC. In June 2020, AMES completed the remediation required by the Record of Decision issued by DEC in 2019 and filed a Construction Completion Report, a Site Management Plan and an environmental easement with DEC. DEC has approved the Site Management Plan, which requires annual inspection of the site cover and groundwater monitoring every five years. AMES also has completed an investigation of certain areas adjacent to the site perimeter and a statistical analysis to determine the area, if any, required to be remediated. DEC has informed AMES that no further investigation or remediation is required. AMES has a number of defenses to liability in this matter, including its rights under a previous Consent Judgment entered into between DEC and a predecessor of AMES relating to the site. AMES’ insurer has accepted AMES’ claim for a substantial portion of the costs incurred and to be incurred for both the on-site and off-site activities. Memphis, TN site. Hunter Fan Company (“Hunter”) operated headquarters and a production plant in Memphis, TN for over 50 years (the “Memphis Site”). While Hunter completed certain on-site remediation of PCB-contaminated soils, Hunter did not investigate the extent to which PCBs existed beneath the building itself nor determine whether off-site areas had been impacted. Hunter vacated the site approximately twenty years ago, and the on-site buildings have now been demolished. The State of Tennessee Department of Environment and Conservation (“TDEC”) identified the Memphis site as being potentially contaminated, raising the possibility that site operations could have resulted in soil and groundwater contamination involving volatile organic compounds and metals. The TDEC performed a preliminary assessment of the site and recommended to the United States Environmental Protection Agency (“EPA”) that the site be listed on the National Priorities List established under CERCLA. The TDEC further recommended that the EPA fund an investigation of potential soil gas contamination in receptors near the site. The TDEC has also indicated that it will proceed with this investigation if the EPA does not act. It is unknown whether the EPA will add the Memphis Site to the National Priorities List, whether a site investigation will reveal contamination and, if there is contamination, the extent of such contamination. However, given that certain PCB work was not completed in the past and the TDEC’s stated intent for the EPA to perform an investigation (and the statement by the TDEC that it will perform the investigation if the EPA will not), liability is probable in this matter. There are other potentially responsible parties for this site, including a former owner of Hunter; Hunter has notified such former owner of this matter, which may have certain liability for any required remediation. If the EPA decides to add this site to the National Priorities List, a Remedial Investigation/Feasibility Study (“RI/FS”) will be required. Hunter expects that EPA will ask it to perform this work. If Hunter does not reach an agreement with the EPA to perform this work, the EPA will implement the RI/FS on its own. Should the EPA implement the RI/FS or perform further studies and/or subsequently remediate the site without first reaching an agreement with one or more relevant parties, the EPA would likely seek from such parties, including Hunter, reimbursement for the costs incurred. General legal Griffon is subject to various laws and regulations relating to the protection of the environment and is a party to legal proceedings arising in the ordinary course of business. Management believes, based on facts presently known to it, that the resolution of the matters above and such other matters will not have a material adverse effect on Griffon’s consolidated financial position, results of operations or cash flows.