v3.25.2
Revenue - Additional Information (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Sep. 30, 2024
Cellulosics [Member] | Product Concentration Risk [Member] | Sales Revenue [Member]          
Revenue From Contracts With Customers [Line Items]          
Concentration risk percentage 40.00% 36.00% 39.00% 37.00%  
Polyvinylpyrrolidones (PVP) [Member] | Product Concentration Risk [Member] | Sales Revenue [Member]          
Revenue From Contracts With Customers [Line Items]          
Concentration risk percentage 25.00% 21.00% 25.00% 22.00%  
Trade Receivable [Member]          
Revenue From Contracts With Customers [Line Items]          
Trade receivables $ 158   $ 158   $ 206