EMPLOYEE BENEFIT PLANS - Additional Information on Pension Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Changes in plan assets:
Fair value of plan assets, beginning of year	$ 185.1
Fair value of plan assets, end of year	217.0	$ 185.1
Amounts recognized in statement of financial position
Deferred charges and other	38.8	98.7
Other long-term liabilities	99.0	111.1
Accumulated other comprehensive loss	$ (235.3)	(284.7)
Weighted average assumptions
Defined Benefit Plan, Type [Extensible Enumeration]	Pension Plan [Member]
U.S. Plans
Changes in benefit obligation:
Benefit obligation, beginning of year	$ 76.0	80.2
Obligations assumed from acquisition	0.0	0.0
Service cost	0.5	0.7	$ 0.4
Interest cost	1.8	2.2	2.8
Actuarial (gain) loss	(2.6)	2.3
Settlements and curtailments	0.0	(4.6)
Plan Amendments	0.0	0.0
Benefits paid	(4.3)	(4.8)
Foreign currency exchange rate changes	0.0	0.0
Benefit obligation, end of year	71.4	76.0	80.2
Changes in plan assets:
Fair value of plan assets, beginning of year	64.6	68.6
Assets assumed from acquisition	0.0	0.0
Actual return on plan assets	9.0	5.1
Employer contributions	0.3	0.3
Settlements and curtailments	0.0	(4.6)
Benefits paid	(4.3)	(4.8)
Foreign currency exchange rate changes	0.0	0.0
Fair value of plan assets, end of year	69.6	64.6	68.6
Funded Status	(1.8)	(11.4)
Amounts recognized in statement of financial position
Deferred charges and other	0.0	0.0
Other accrued expenses	0.1	0.3
Other long-term liabilities	1.7	11.1
Accumulated other comprehensive loss	$ 9.4	$ 18.8
Weighted average assumptions
Discount rate	2.70%	2.46%
Non U.S. Plans
Changes in benefit obligation:
Benefit obligation, beginning of year	$ 158.7	$ 153.4
Obligations assumed from acquisition	19.0	0.0
Service cost	1.5	1.7	1.4
Interest cost	2.1	1.9	2.9
Actuarial (gain) loss	(3.4)	(2.5)
Settlements and curtailments	0.0	(1.6)
Plan Amendments	0.1	0.0
Benefits paid	(5.0)	(3.5)
Foreign currency exchange rate changes	3.1	9.3
Benefit obligation, end of year	176.1	158.7	153.4
Changes in plan assets:
Fair value of plan assets, beginning of year	120.5	112.1
Assets assumed from acquisition	17.2	0.0
Actual return on plan assets	4.6	0.8
Employer contributions	6.6	4.7
Settlements and curtailments	0.0	0.0
Benefits paid	(5.0)	(3.5)
Foreign currency exchange rate changes	3.5	6.4
Fair value of plan assets, end of year	147.4	120.5	$ 112.1
Funded Status	(28.7)	(38.2)
Amounts recognized in statement of financial position
Deferred charges and other	12.4	3.0
Other accrued expenses	0.0	0.0
Other long-term liabilities	41.1	41.3
Accumulated other comprehensive loss	$ 43.2	$ 50.1
Weighted average assumptions
Rate of compensation increase	2.50%	2.25%
Minimum | Non U.S. Plans
Weighted average assumptions
Discount rate	1.00%	0.85%
Maximum | Non U.S. Plans
Weighted average assumptions
Discount rate	2.00%	1.75%