v3.22.2.2
RETIREMENT PLANS - Benefit Obligations, Plan Assets, Annual Expense, Assumptions and Other Information of the Company's Defined Benefit Pension Plans (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Amounts recognized in the Consolidated Balance Sheets consist of:    
Non-current assets $ 69.6 $ 89.9
Non-current liabilities (82.1) (98.2)
International Plan | Defined Benefit Pension Plan    
Change in projected benefit obligation:    
Benefit obligation at beginning of year 193.6 193.7
Interest cost 3.0 2.6
Actuarial gain (55.1) (2.9)
Benefits paid (7.5) (7.6)
Foreign currency translation (24.8) 7.8
Projected benefit obligation (“PBO”) at end of year 109.2 193.6
Accumulated benefit obligation (“ABO”) at end of year 109.2 193.6
Change in plan assets:    
Fair value of plan assets at beginning of year 221.6 209.9
Actual return on plan assets (61.2) 2.1
Employer contribution 5.3 7.9
Benefits paid (7.5) (7.6)
Foreign currency translation (29.3) 9.3
Fair value of plan assets at end of year 128.9 221.6
Unfunded status at end of year 19.7 28.0
Information for pension plans with an ABO in excess of plan assets:    
Accumulated benefit obligation 11.6 16.9
Fair value of plan assets 0.0 0.0
Projected benefit obligation 11.6 16.9
Amounts recognized in the Consolidated Balance Sheets consist of:    
Non-current assets 31.3 44.9
Current liabilities (0.8) (0.9)
Non-current liabilities (10.8) (16.0)
Total amount accrued 19.7 28.0
Amounts recognized in AOCL consist of:    
Actuarial loss 51.2 51.4
Prior service cost 2.1 2.7
Total amount recognized 53.3 54.1
Total change in other comprehensive loss attributable to:    
Net gain (loss) during the period (11.1) (0.6)
Reclassification to net income 1.3 1.3
Foreign currency translation 10.6 (2.0)
Total change in other comprehensive loss $ 0.8 $ (1.3)
Weighted average assumptions used in development of projected benefit obligation:    
Discount rate 4.96% 1.90%
U.S. Plan | Defined Benefit Pension Plan    
Change in projected benefit obligation:    
Benefit obligation at beginning of year $ 100.2 $ 109.8
Interest cost 1.7 1.5
Actuarial gain (17.2) (4.1)
Benefits paid (7.0) (7.0)
Foreign currency translation 0.0 0.0
Projected benefit obligation (“PBO”) at end of year 77.7 100.2
Accumulated benefit obligation (“ABO”) at end of year 77.7 100.2
Change in plan assets:    
Fair value of plan assets at beginning of year 81.7 81.5
Actual return on plan assets (15.8) 5.9
Employer contribution 0.2 1.3
Benefits paid (7.0) (7.0)
Foreign currency translation 0.0 0.0
Fair value of plan assets at end of year 59.1 81.7
Unfunded status at end of year (18.6) (18.5)
Information for pension plans with an ABO in excess of plan assets:    
Accumulated benefit obligation 77.7 100.2
Fair value of plan assets 59.1 81.7
Projected benefit obligation 77.7 100.2
Amounts recognized in the Consolidated Balance Sheets consist of:    
Non-current assets 0.0 0.0
Current liabilities (0.2) (0.2)
Non-current liabilities (18.4) (18.3)
Total amount accrued (18.6) (18.5)
Amounts recognized in AOCL consist of:    
Actuarial loss 38.8 39.2
Prior service cost 0.0 0.0
Total amount recognized 38.8 39.2
Total change in other comprehensive loss attributable to:    
Net gain (loss) during the period (1.3) 6.6
Reclassification to net income 1.7 2.1
Foreign currency translation 0.0 0.0
Total change in other comprehensive loss $ 0.4 $ 8.7
Weighted average assumptions used in development of projected benefit obligation:    
Discount rate 5.06% 2.37%