COMMITMENTS AND CONTINGENCIES	6 Months Ended
COMMITMENTS AND CONTINGENCIES	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Legal and environmental Peekskill Site. Lightron Corporation (“Lightron”), a wholly-owned subsidiary of Griffon, once conducted operations at a location in Peekskill in the Town of Cortlandt, New York (the “Peekskill Site”) owned by ISC Properties, Inc. (“ISCP”), a wholly-owned subsidiary of Griffon. ISCP sold the Peekskill Site in November 1982. Subsequently, ISCP was advised by the Department of Environmental Conservation of New York State ("DEC") that random sampling at the Peekskill Site and in a creek near the Peekskill Site indicated concentrations of solvents and other chemicals common to Lightron’s prior plating operations. In 1996, ISCP entered into a consent order with the DEC (the “Consent Order”), pursuant to which ISCP was required to perform a remedial investigation and prepare a feasibility study (the “Feasibility Study”). After completing the initial remedial investigation, ISCP conducted, over the next several years, supplemental remedial investigations, including soil vapor investigations, as required by the Consent Order. In April 2009, the DEC advised ISCP that both the DEC and the New York State Department of Health had reviewed and accepted an August 2007 Remedial Investigation Report and an Additional Data Collection Summary Report dated January 30, 2009. ISCP submitted to the DEC a draft Feasibility Study which was accepted and approved by the DEC in February 2011. ISCP satisfied its obligations under the Consent Order when DEC approved the Remedial Investigation and Feasibility Study for the Peekskill Site. In June, 2011 the DEC issued a Remedial Action Plan for the Peekskill Site that set forth the specific remedies selected and responded to public comments. The approximate cost of the remedy proposed by DEC in its Remedial Action Plan was approximately $10,000. Following issuance of the Remedial Action Plan, the DEC implemented a portion of its plan, and also performed additional investigation for the presence of metals in soils and sediments downstream from the Peekskill Site. During this investigation chromium was found to be present in sediments further downstream of the Peekskill site than previously detected. In August 2018, the DEC sent a letter to the United States Environmental Protection Agency (the “EPA”), in which the DEC requested that the Peekskill Site be nominated by the EPA for inclusion on the National Priorities List (the “NPL”). Based on DEC’s request and on an analysis by a consultant retained by the EPA, on May 15, 2019 the EPA added the Peekskill Site to the NPL under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) and is now performing a Remedial Investigation/Feasibility Study. The EPA estimates that it will select a remedy in 2022. The EPA has announced that it is performing its own remedial investigation/feasibility study of the site. It is uncertain what subsequent action the EPA will take. The EPA may, on its own or through the use of consultants, perform further studies of the site and/or subsequently remediate the site, and in such event, would likely seek reimbursement for the costs incurred from potentially responsible parties (“PRPs”). Alternatively, the EPA could enter into negotiations with the PRPs to request that the PRPs perform further studies and/or remediate the site. Griffon does not acknowledge any responsibility to perform any remediation at the Peekskill Site. Improper Advertisement Claim involving Union Tools® Products. Beginning in December 2004, a customer of AMES had been named in various litigation matters relating to certain Union Tools products. The plaintiffs in those litigation matters asserted causes of action against the customer of AMES for improper advertisement to end consumers. The allegations suggested that advertisements led the consumers to believe that Union Tools’ hand tools were wholly manufactured within boundaries of the United States. The complaints asserted various causes of action against the customer of AMES under federal and state law, including common law fraud. At some point, the customer may seek indemnity (including recovery of its legal fees and costs) against AMES for an unspecified amount. Presently, AMES cannot estimate the amount of loss, if any, if the customer were to seek legal recourse against AMES. 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 has entered into an Order on Consent with the New York State Department of Environmental Conservation. While the Order is without admission or finding of liability or acknowledgment that there has been a release of hazardous substances at the site, AMES is required to perform a remedial investigation and to recommend a remediation option. At the conclusion of the remediation phase to the satisfaction of the DEC, the DEC will issue a Certificate of Completion. AMES has performed significant investigative and remedial activities over the last few years under work plans approved by the DEC and is currently implementing a Remedial Action Work Plan for the site property that was approved by the DEC; the work required by such Remedial Action Work Plan is expected to be completed by summer 2020. The DEC has also requested that AMES develop a work plan to investigate certain areas immediately adjacent to the former Union Fork and Hoe site. AMES has a number of defenses to liability in this matter, including its rights under a previous Consent Judgment entered into between the DEC and a predecessor of AMES relating to the site. U.S. Government investigations and claims Defense contracts and subcontracts, including Griffon’s contracts and subcontracts, are subject to audit and review by various agencies and instrumentalities of the United States government, including among others, the Defense Contract Audit Agency, the Defense Criminal Investigative Service, and the Department of Justice which has responsibility for asserting claims on behalf of the U.S. Government. In general, departments and agencies of the U.S. Government have the authority to investigate various transactions and operations of Griffon, and the results of such investigations may lead to administrative, civil or criminal proceedings, the ultimate outcome of which could be fines, penalties, repayments or compensatory or treble damages. U.S. Government regulations provide that certain findings against a contractor may lead to suspension or debarment from future U.S. Government contracts or the loss of export privileges for a company or an operating division or subdivision. Suspension or debarment could have a material adverse effect on Telephonics because of its reliance on government contracts. 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.