Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES LEGAL PROCEEDINGS AND OTHER CONTINGENCIES We periodically become a party to legal proceedings, arbitrations, regulatory proceedings, inquiries and investigations (“contingencies”) arising in the ordinary course of our business operations. The ultimate resolution of these contingencies is subject to significant uncertainty, and should we fail to prevail in any of them or should several of them be resolved against us in the same reporting period, these matters could, individually or in the aggregate, be material to our Consolidated Financial Statements. One of these contingencies, related to Star Lake Canal, which we assumed in connection with the KMG Acquisition, is discussed below. The ultimate outcome of these matters, however, cannot be determined at this time, nor can the amount of any potential loss be reasonably estimated, and as a result except where indicated no amounts have been recorded in our Consolidated Financial Statements. In connection with the KMG Acquisition, through KMG-Bernuth as of the KMG Acquisition Date, we assumed a contingency related to the Star Lake Canal Superfund Site near Beaumont, Texas (“Star Lake”). In 2014, prior to the KMG Acquisition, the United States Environmental Protection Agency (“EPA”) had notified KMG-Bernuth that the EPA considered it to be a potentially responsible party under the Comprehensive Environmental Response, Compensation and Liability Act of 1980, as amended, in connection with Star Lake. Although KMG-Bernuth has not conceded liability with respect to Star Lake, and has asserted to the EPA and other parties its defenses to any liability, KMG-Bernuth and seven other cooperating parties entered into an agreement with the EPA in September 2016 to complete a remedial design of the remediation actions for the site and recorded a reserve at that time. In the fourth quarter of fiscal 2021, an additional reserve for the anticipated remedial action phase, which will be performed under a separate future agreement, was established for $2,508, resulting in a total remaining reserve for the remediation of $2,711 as of September 30, 2021. Separately, in fiscal 2019, a fire, which involved non-hazardous waste materials and caused no injuries, occurred at the warehouse of the wood treatment facility of our subsidiary KMG-Bernuth, Inc. (“KMG-Bernuth”), in Tuscaloosa, Alabama, which processes pentachlorophenol (“penta”) for sale to customers in the U.S. and Canada. KMG-Bernuth commenced and completed cleanup with oversight from certain local, state and federal authorities, and we recorded related expense and for disposal of affected inventory in Cost of sales. We recorded expense of $26, $1,551 and $9,494 for the years ended September 30, 2021, 2020, and 2019, respectively. Although we believe we have completed cleanup efforts related to the fire incident, there are potential other related costs that cannot be reasonably estimated as of this time due to the nature of federally-regulated penta-related requirements. In addition, we continue to work with our insurance carriers on possible recovery of losses and costs related to the fire incident. We received $1,076 and $468 of insurance recoveries during the years ended September 30, 2021 and 2020, respectively, which was recorded in Cost of sales. At this point we cannot reasonably estimate whether we will receive any additional insurance recoveries, or if so, the amount of such recoveries. We also may face other governmental or third-party claims, or otherwise incur costs, relating to cleanup of, or for injuries resulting from, contamination at sites associated with this or other past and present operations. We accrue for environmental liabilities when a determination can be made that they are probable and reasonably estimable. Other than as described herein, we are not involved in any legal proceedings that we believe could have a material impact on our consolidated financial position, results of operations or cash flows. In addition, our Company is subject to extensive federal, state and local laws, regulations and ordinances in the U.S. and in other countries. These regulatory requirements relate to the use, generation, storage, handling, emission, transportation and discharge of certain hazardous materials, substances and waste into the environment. The Company, including its KMG entities, manage Environmental, Health and Safety (“EHS”) matters related to protection of the environment and human health, the cleanup of contaminated sites, the treatment, storage and disposal of wastes, and the emission of substances into the air or waterways, among other EHS concerns. Governmental authorities can enforce compliance with their regulations, and violators may be subject to fines, injunctions or both. The Company devotes significant financial resources to compliance, including costs for ongoing compliance. Certain licenses, permits and product registrations are required for the Company’s products and operations in the U.S., Mexico and other countries in which it does business. The licenses, permits and product registrations are subject to revocation, modification and renewal by governmental authorities. In the U.S. in particular, producers and distributors of penta, which is a product manufactured and sold by KMG-Bernuth as part of the wood treatment business, are subject to registration and notification requirements under the Federal Insecticide, Fungicide and Rodenticide Act and comparable state law in order to sell this product in the U.S. Compliance with these requirements may have a significant effect on our business, financial condition and results of operations. We are subject to contingencies, including litigation relating to EHS laws and regulations, commercial disputes and other matters. Certain of these contingencies are discussed above and below. The ultimate resolution of these contingencies is subject to significant uncertainty, and should we fail to prevail in any of them or should several of them be resolved against us in the same reporting period, these matters could, individually or in the aggregate, be material to the Consolidated Financial Statements. The ultimate outcome of these matters cannot be determined at this time, nor can the amount of any potential loss be reasonably estimated, and as a result except where indicated no amounts have been recorded in our Consolidated Financial Statements. INDEMNIFICATION In the normal course of business, we are a party to a variety of agreements pursuant to which we may be obligated to indemnify the other party with respect to certain matters. Generally, these obligations arise in the context of agreements entered into by us, under which we customarily agree to hold the other party harmless against losses arising from items such as a breach of certain representations and covenants including title to assets sold, certain intellectual property rights and certain environmental matters. These terms are common in the industries in which we conduct business. In each of these circumstances, payment by us is subject to certain monetary and other limitations and is conditioned on the other party making an adverse claim pursuant to the procedures specified in the particular agreement, which typically allow us to challenge the other party’s claims. We evaluate estimated losses for such indemnifications under the accounting standards related to contingencies and guarantees. We consider such factors as the degree of probability of an unfavorable outcome and the ability to make a reasonable estimate of the amount of loss. To date, we have not experienced material costs as a result of such obligations and, as of September 30, 2021, have not recorded any liabilities related to such indemnifications in our financial statements as we do not believe the likelihood of such obligations is probable. PURCHASE OBLIGATIONS Purchase obligations include take-or-pay arrangements with suppliers, and purchase orders and other obligations entered into in the normal course of business regarding the purchase of goods and services. We have been operating under an abrasive particle supply agreement, the current term of which runs through December 2022. As of September 30, 2021, purchase obligations include $11,030 of contractual commitments related to this agreement. In addition, we have a purchase commitment of $15,133 to purchase non-water based carrier fluid.