RETIREMENT PLANS - NET PERIODIC BENEFIT (INCOME) COST (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Pension Plan
Net periodic benefit (income) cost for the year:
Service cost	$ 0	$ 50
Interest cost	258	304
Expected return on plan assets	(546)	(680)
Amortization of prior service cost (credit)	0	1
Amortization of net actuarial loss	39	35
Curtailment cost (income)	0	53
Net periodic benefit (income) cost	(249)	(237)
SERP
Net periodic benefit (income) cost for the year:
Service cost	0	3
Interest cost	51	63
Expected return on plan assets	0	0
Amortization of prior service cost (credit)	0	(1)
Amortization of net actuarial loss	0	5
Curtailment cost (income)	0	(53)
Net periodic benefit (income) cost	51	17
Post-retirement Medical
Net periodic benefit (income) cost for the year:
Service cost	0	0
Interest cost	48	80
Expected return on plan assets	0	0
Amortization of prior service cost (credit)	0	0
Amortization of net actuarial loss	62	80
Curtailment cost (income)	0	0
Net periodic benefit (income) cost	$ 110	$ 160