v3.22.2.2
RETIREMENT PLANS - Components of Net Periodic Benefit Cost and Weighted Average Assumptions (Details) - Defined Benefit Pension Plan - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2020
International Plan      
Components of net periodic benefit cost (income):      
Interest cost $ 3.0 $ 2.6 $ 2.7
Expected return on plan assets (5.1) (5.5) (6.9)
Net amortization 1.3 1.3 1.0
Net periodic benefit cost (income) $ (0.8) $ (1.6) $ (3.2)
Weighted average assumptions used in development of net periodic benefit cost (income):      
Weighted average discount rate - interest cost 1.64% 1.26% 1.42%
Expected return on plan assets 2.37% 2.45% 3.39%
U.S. Plan      
Components of net periodic benefit cost (income):      
Interest cost $ 1.7 $ 1.5 $ 2.6
Expected return on plan assets (2.8) (3.4) (3.9)
Net amortization 1.7 2.1 1.8
Net periodic benefit cost (income) $ 0.6 $ 0.2 $ 0.5
Weighted average assumptions used in development of net periodic benefit cost (income):      
Weighted average discount rate - interest cost 1.74% 1.43% 2.44%
Expected return on plan assets 3.50% 4.25% 5.00%