v3.26.3
Retirement Benefits - Schedule of Significant Assumptions Used in Determining Benefit Obligations (Details)
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2024
U.S. Plans      
Defined Benefit Plan Disclosure [Line Items]      
Expected gross health care cost trend rate 5.00%    
Pension Benefits | U.S. Plans      
Defined Benefit Plan Disclosure [Line Items]      
Discount rate 6.70% 5.35% 5.10%
Compensation increase rate 3.50% 3.50%  
Health care cost trend rate 0.00% 0.00%  
Pension Benefits | Non-U.S. Plans      
Defined Benefit Plan Disclosure [Line Items]      
Discount rate 4.84% 4.07%  
Compensation increase rate 2.88% 2.85%  
Health care cost trend rate 0.00% 0.00%  
Other Postretirement Benefits | U.S. Plans      
Defined Benefit Plan Disclosure [Line Items]      
Discount rate 6.30% 5.07%  
Compensation increase rate 0.00% 0.00%  
Health care cost trend rate 9.11% 7.53%  
Expected gross health care cost trend rate 0.00%    
Other Postretirement Benefits | Non-U.S. Plans      
Defined Benefit Plan Disclosure [Line Items]      
Discount rate 5.30% 4.45%  
Compensation increase rate 0.00% 0.00%  
Health care cost trend rate 4.50% 4.50%