RETIREMENT PLANS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Pension Plan
Net periodic benefit cost:
Service cost (credit)	$ 54	$ 34	$ 162	$ 178
Interest cost	88	78	266	252
Expected return on plan assets	(147)	(122)	(443)	(404)
Amortization of prior service cost (credit)	2	2	5	4
Amortization of net actuarial loss	25	21	74	103
Net periodic benefit cost	22	13	64	133
Other disclosures
Contribution by the entity to the Pension Plan			200
Estimated future employer contributions	300		300
SERP
Net periodic benefit cost:
Service cost (credit)	10	(5)	30	26
Interest cost	19	1	57	42
Expected return on plan assets	0	0	0	0
Amortization of prior service cost (credit)	(1)	(2)	(4)	(4)
Amortization of net actuarial loss	3	(17)	10	0
Net periodic benefit cost	31	(23)	93	64
Postretirement Medical
Net periodic benefit cost:
Service cost (credit)	0	0	0	0
Interest cost	19	22	57	66
Expected return on plan assets	0	0	0	0
Amortization of prior service cost (credit)	0	0	0	0
Amortization of net actuarial loss	2	47	8	141
Net periodic benefit cost	$ 21	$ 69	$ 65	$ 207