RETIREMENT PLANS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Pension Plan
Net periodic benefit cost:
Service cost	$ 50	$ 55	$ 100	$ 108
Interest cost	94	89	187	178
Expected return on plan assets	(160)	(148)	(321)	(296)
Amortization of prior service cost (credit)	2	2	3	3
Amortization of net actuarial loss	1	27	4	49
Net periodic benefit (income) cost	(13)	25	(27)	42
Other disclosures
Contribution by the entity to the Pension Plan			115
SERP
Net periodic benefit cost:
Service cost	9	13	18	20
Interest cost	21	23	42	38
Amortization of prior service cost (credit)	(1)	(1)	(2)	(3)
Amortization of net actuarial loss	1	7	2	7
Net periodic benefit (income) cost	30	42	60	62
Postretirement Medical
Net periodic benefit cost:
Service cost	0	0	0	0
Interest cost	25	19	50	38
Amortization of prior service cost (credit)	0	0	0	0
Amortization of net actuarial loss	13	3	26	6
Net periodic benefit (income) cost	$ 38	$ 22	$ 76	$ 44