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, 2025	Sep. 30, 2024
Amounts recognized in the Consolidated Balance Sheets consist of:
Non-current assets	$ 56.3	$ 62.7
Non-current liabilities	(64.3)	(73.0)
International Plan | Defined Benefit Pension Plan
Change in projected benefit obligation:
Benefit obligation at beginning of year	123.2	108.5
Interest cost	5.5	5.9
Actuarial (gain) loss	(7.7)	5.1
Benefits paid	(7.1)	(6.6)
Foreign currency translation	0.9	10.3
Projected benefit obligation (“PBO”) at end of year	114.8	123.2
Accumulated benefit obligation (“ABO”) at end of year	114.8	123.2
Change in plan assets:
Fair value of plan assets at beginning of year	141.4	124.8
Actual return on plan assets	(8.5)	10.0
Employer contribution	0.9	0.9
Benefits paid	(7.1)	(6.6)
Foreign currency translation	0.3	12.3
Fair value of plan assets at end of year	127.0	141.4
Overfunded (underfunded) status at end of year	12.2	18.2
Information for pension plans with an ABO in excess of plan assets:
Accumulated benefit obligation	11.5	12.0
Fair value of plan assets	0.0	0.0
Projected benefit obligation	11.5	12.0
Amounts recognized in the Consolidated Balance Sheets consist of:
Non-current assets	23.8	30.2
Current liabilities	(1.0)	(0.9)
Non-current liabilities	(10.6)	(11.1)
Total amount accrued	12.2	18.2
Amounts recognized in AOCL consist of:
Actuarial loss	68.8	64.1
Prior service cost	2.2	2.3
Total amount recognized	71.0	66.4
Total change in other comprehensive loss attributable to:
Net loss during the period	(6.5)	(0.7)
Reclassification to net earnings	2.5	2.3
Foreign currency translation	(0.6)	(5.9)
Total change in other comprehensive loss	$ (4.6)	$ (4.3)
Weighted average assumptions used in development of projected benefit obligation:
Discount rate	5.50%	4.86%
U.S. Plan | Defined Benefit Pension Plan
Change in projected benefit obligation:
Benefit obligation at beginning of year	$ 74.2	$ 71.8
Interest cost	3.1	3.7
Actuarial (gain) loss	(1.7)	5.5
Benefits paid	(6.7)	(6.8)
Foreign currency translation	0.0	0.0
Projected benefit obligation (“PBO”) at end of year	68.9	74.2
Accumulated benefit obligation (“ABO”) at end of year	68.9	74.2
Change in plan assets:
Fair value of plan assets at beginning of year	57.3	54.1
Actual return on plan assets	0.6	7.1
Employer contribution	8.2	2.9
Benefits paid	(6.7)	(6.8)
Foreign currency translation	0.0	0.0
Fair value of plan assets at end of year	59.4	57.3
Overfunded (underfunded) status at end of year	(9.5)	(16.9)
Information for pension plans with an ABO in excess of plan assets:
Accumulated benefit obligation	68.9	74.2
Fair value of plan assets	59.4	57.3
Projected benefit obligation	68.9	74.2
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	(9.3)	(16.7)
Total amount accrued	(9.5)	(16.9)
Amounts recognized in AOCL consist of:
Actuarial loss	32.4	34.1
Prior service cost	0.0	0.0
Total amount recognized	32.4	34.1
Total change in other comprehensive loss attributable to:
Net loss during the period	0.0	(0.5)
Reclassification to net earnings	1.7	1.7
Foreign currency translation	0.0	0.0
Total change in other comprehensive loss	$ 1.7	$ 1.2
Weighted average assumptions used in development of projected benefit obligation:
Discount rate	4.94%	4.62%