SEGMENT INFORMATION - Capital Expenditures 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 capital expenditures	$ 59.0	$ 64.0	$ 43.6
Operating Segments
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total capital expenditures	21.1	37.5	31.5
Operating Segments | GPC
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total capital expenditures	10.1	17.7	18.6
Operating Segments | H&G
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total capital expenditures	3.8	8.2	3.6
Operating Segments | HPC
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total capital expenditures	7.2	11.6	9.3
Corporate and shared operations
Segment Reporting, Other Significant Reconciling Item [Line Items]
Total capital expenditures	$ 37.9	$ 26.5	$ 12.1