FAIR VALUE MEASUREMENT OF FINANCIAL INSTRUMENTS - Supplemental Fair Value Information about Long-Term Fixed-Rate Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Sep. 30, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, net, carrying value	$ 544,996	$ 542,610
Carrying value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, net, carrying value	545,000	542,600
Fair value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, net, fair value	$ 443,300	$ 430,700