v3.26.1
RELATED PARTY TRANSACTIONS (Details) - USD ($)
3 Months Ended 9 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Sep. 30, 2025
Related Party Transaction [Line Items]          
Total sales $ 215,300,000 $ 214,600,000 $ 1,064,600,000 $ 1,016,400,000  
Total receivables 149,900,000   149,900,000   $ 179,600,000
Accounts payable 92,400,000   92,400,000   96,000,000.0
Purchased of salt-treatment materials 0.0   2,200,000    
Related Party          
Related Party Transaction [Line Items]          
Total sales 100,000 $ 900,000 1,000,000.0 $ 2,900,000  
Total receivables 100,000   100,000   200,000
Accounts payable 0   0   $ 0
Related Party | Salt-Treatment Material Purchase          
Related Party Transaction [Line Items]          
Accounts payable $ 0   $ 0