v3.26.1
Pension Benefit Obligations - Schedule of Components of Net Periodic Cost for Pension Plans (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
U.S.        
Defined Benefit Plan Disclosure [Line Items]        
Service costs $ 0.0 $ 0.0 $ 0.0 $ 0.0
Interest cost on projected benefit obligation 1.9 $ 2.0 $ 5.6 5.9
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]   Other income (loss) Other income (loss)  
Expected return on plan assets $ (1.3) $ (1.2) $ (3.8) $ (3.6)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Other income (loss)     Other income (loss)
Amortization of prior service cost $ 0.0 0.0 $ 0.0 $ 0.0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization of Prior Service Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration]     Other income (loss) Other income (loss)
Amortization of net loss (gain) 1.0 0.9 $ 2.9 $ 2.8
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]     Other income (loss) Other income (loss)
Net periodic benefit cost (credit) 1.6 1.7 $ 4.7 $ 5.1
Int’l        
Defined Benefit Plan Disclosure [Line Items]        
Service costs 0.0 0.0 0.1 0.1
Interest cost on projected benefit obligation $ 10.1 10.2 30.3 $ 29.7
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration] Other income (loss)     Other income (loss)
Expected return on plan assets $ (14.0) $ (13.3) $ (41.8) $ (38.6)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]   Other income (loss) Other income (loss)  
Amortization of prior service cost $ 0.1 $ 0.1 $ 0.1 0.1
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization of Prior Service Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration] Other income (loss) Other income (loss)    
Amortization of net loss (gain) $ (0.1) $ (0.4) (0.4) (1.0)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Other income (loss) Other income (loss)    
Net periodic benefit cost (credit) $ (3.9) $ (3.4) $ (11.7) $ (9.7)