SEGMENT INFORMATION - Depreciation and Amortization Relating to Segments (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total depreciation and amortization	$ 91.2	$ 99.3	$ 117.0
Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total depreciation and amortization	76.6	84.7	102.4
Operating Segments | GPC
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total depreciation and amortization	37.4	37.4	39.2
Operating Segments | H&G
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total depreciation and amortization	18.8	18.6	19.2
Operating Segments | HPC
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total depreciation and amortization	20.4	28.7	44.0
Corporate and shared operations
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total depreciation and amortization	$ 14.6	$ 14.6	$ 14.6