v3.26.1
Fair Value Measurements - Schedule of the Fair Value Hierarchy for Assets and Liabilities (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Sep. 30, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total assets $ 34 $ 37
Total liabilities 12 14
Foreign currency exchange derivatives    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other current assets $ 29 $ 36
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Other current assets Other current assets
Other noncurrent assets $ 1 $ 1
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration]   Other noncurrent assets
Other current liabilities 11 $ 7
Other noncurrent liabilities 1 3
Cross-currency interest rate swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other current assets 3  
Other noncurrent assets $ 1  
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration] Other noncurrent assets  
Other current liabilities   1
Other noncurrent liabilities   3
Quoted Prices in Active Markets (Level 1)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total assets $ 0 0
Total liabilities 0 0
Quoted Prices in Active Markets (Level 1) | Foreign currency exchange derivatives    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other current assets 0 0
Other noncurrent assets 0 0
Other current liabilities 0 0
Other noncurrent liabilities 0 0
Quoted Prices in Active Markets (Level 1) | Cross-currency interest rate swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other current assets 0  
Other noncurrent assets 0  
Other current liabilities   0
Other noncurrent liabilities   0
Significant Other Observable Inputs (Level 2)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total assets 34 37
Total liabilities 12 14
Significant Other Observable Inputs (Level 2) | Foreign currency exchange derivatives    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other current assets 29 36
Other noncurrent assets 1 1
Other current liabilities 11 7
Other noncurrent liabilities 1 3
Significant Other Observable Inputs (Level 2) | Cross-currency interest rate swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other current assets 3  
Other noncurrent assets 1  
Other current liabilities   1
Other noncurrent liabilities   3
Significant Unobservable Inputs (Level 3)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total assets 0 0
Total liabilities 0 0
Significant Unobservable Inputs (Level 3) | Foreign currency exchange derivatives    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other current assets 0 0
Other noncurrent assets 0 0
Other current liabilities 0 0
Other noncurrent liabilities 0 0
Significant Unobservable Inputs (Level 3) | Cross-currency interest rate swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other current assets 0  
Other noncurrent assets $ 0  
Other current liabilities   0
Other noncurrent liabilities   $ 0