v3.25.4
FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Additional Information (Details) - USD ($)
$ in Millions
 3 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Sep. 30, 2025
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Gains recorded in interest expense $ (9.7) $ (15.9)  
Carrying value of impaired asset 0.7 0.3  
Long-lived assets, fair value 0.5 0.0  
Impairment of long lived assets 0.2 0.3  
Customized Polymer Solutions      
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Impairment of long lived assets 0.2 0.3  
Interest rate derivatives | Cash Flow Hedging      
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Derivative, notional amount $ 275.0   $ 562.5
Derivative, forward interest rate 1.16%    
Gains reclassified to earnings $ 2.0 6.2  
Gain to be reclassified within next twelve months 7.5    
Foreign Currency Forward Contracts      
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Derivative, notional amount 118.2   165.0
Gain (loss) recorded under fair value contracts 0.3 (1.9)  
Unrealized (losses) gains on foreign currency (0.8) 0.1  
Cross currency swap      
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Derivative, notional amount $ 534.9   $ 534.9
Derivative, forward interest rate 1.64%    
Gains recorded in interest expense $ 2.2 $ 1.5