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DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Accounts receivable, expected loss allowance for doubtful accounts and concentrations of credit risk (Details) - USD ($) $ in Thousands | 12 Months Ended
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Sep. 30, 2025 | Sep. 30, 2024
Description Of Business And Summary Of Significant Accounting Policies [Line Items] |  |
Customer program reserves and cash discounts netted against accounts receivable | $ 46,766 | $ 64,211
Home Depot | Accounts Receivable | Customer Concentration Risk |  |
Description Of Business And Summary Of Significant Accounting Policies [Line Items] |  |
Concentration risk, percentage | 9.00% | 12.00%

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