DEFINED BENEFIT PLAN - Net periodic benefit costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Components of net periodic expense:
Interest cost	$ 185	$ 182	$ 366	$ 364
Expected return on assets	(197)	(198)	(389)	(396)
Amortization of prior loss	(35)	(37)	(70)	(75)
Net periodic expense	$ (47)	$ (53)	$ (93)	$ (107)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	General and Administrative Expense	General and Administrative Expense	General and Administrative Expense	General and Administrative Expense