EMPLOYEE BENEFIT PLANS - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Components of the net periodic pension expense (benefit)
Interest cost	$ 753	$ 1,097
Expected return on plan assets	(967)	(1,381)
Recognized net actuarial loss	590	669
Settlement	1,015	0
Net pension expense	$ 1,391	$ 385