SEGMENT INFORMATION - Schedule of Segment Information (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment adjusted EBITDA	$ 382.2	$ 306.2	$ 324.4
Interest expense	58.5	116.1	99.4
Depreciation	57.3	48.9	49.0
Amortization	44.5	42.3	50.3
Corporate costs	66.1	41.1	41.3
Unallocated shared service costs	0.0	18.0	27.6
Interest income	(57.5)	(38.3)	(0.6)
Share based compensation	17.5	17.2	10.2
Non-cash impairment charges	50.3	242.6	0.0
Non-cash purchase accounting adjustments	1.2	1.9	8.3
(Gain) loss from early extinguishment of debt	(2.6)	3.0	0.0
Exit and disposal costs	1.0	9.3	10.4
Exit and disposal costs	1.0	9.3	10.4
Global ERP transformation	15.0	11.4	13.1
Gain from remeasurement of contingent consideration liability	0.0	(1.5)	(28.5)
Representation and warranty insurance proceeds	(65.0)	0.0	0.0
Litigation charges	2.9	3.0	1.5
HPC product disposal	0.0	20.6	0.0
Other	3.4	23.4	18.2
Income (loss) from continuing operations before income taxes	163.6	(290.2)	(90.3)
HPC Separation Initiatives
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Exit and disposal costs	13.4	4.2	19.1
HHI separation costs
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest income	(55.7)	(37.9)	0.0
Transaction related charges	3.9	8.4	6.3
Tristar business acquisition and integration
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Transaction related charges	0.0	11.5	24.3
Rejuvenate integration
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Transaction related charges	0.0	0.0	6.8
Armitage integration
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Transaction related charges	0.0	0.0	1.4
Omega integration
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Transaction related charges	0.0	0.0	4.6
Coevorden operations divestiture
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Transaction related charges	0.0	2.7	8.8
HPC brand portfolio transition
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Transaction related charges	0.0	2.5	1.3
GPC
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment adjusted EBITDA	216.1	190.6	168.6
GPC distribution center transition	0.0	0.0	35.8
H&G
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment adjusted EBITDA	90.8	72.5	86.2
HPC
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment adjusted EBITDA	75.3	43.1	69.6
HPC product recall	$ 6.9	$ 7.7	$ 5.5