RESTRUCTURING CHARGES - Reconciliation of Beginning and Ending Restructuring Reserve Balances (Details) $ in Millions	6 Months Ended
	Mar. 31, 2026 USD ($)
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	$ 21.7
Costs incurred and charged to expense	19.0
Costs paid or otherwise settled	(23.6)
Restructuring reserve, ending balance	17.1
Employee Separation Costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	21.3
Costs incurred and charged to expense	12.3
Costs paid or otherwise settled	(16.7)
Restructuring reserve, ending balance	16.9
Other Costs
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	0.4
Costs incurred and charged to expense	6.7
Costs paid or otherwise settled	(6.9)
Restructuring reserve, ending balance	$ 0.2