DEBT - Schedule of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Debt Instrument [Line Items]
Deferred financing costs	$ (10,096)	$ (7,114)
Total debt	760,532	764,838
Less: Current portion	3,730	0
Long-term debt	756,802	764,838
Secured Debt | New Senior Secured Term Loan Facility due September 29, 2032
Debt Instrument [Line Items]
Carrying Value	370,628	371,952
Secured Debt | Senior Notes Due June 1, 2031
Debt Instrument [Line Items]
Carrying Value	400,000	400,000
Secured Debt | ABL Credit Facility
Debt Instrument [Line Items]
Carrying Value	$ 0	$ 0