RETIREMENT PLANS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Pension Plan
Net periodic benefit cost:
Service cost	$ 72	$ 65	$ 144	$ 130
Interest cost	87	91	174	182
Expected return on plan assets	(141)	(112)	(282)	(224)
Amortization of prior service cost (credit)	1	1	2	2
Amortization of net actuarial loss	41	34	82	68
Net periodic benefit cost	60	79	120	158
Other disclosures
Contribution by the entity to the Pension Plan			350
Estimated future employer contributions			650
SERP
Net periodic benefit cost:
Service cost	15	16	31	32
Interest cost	20	20	41	40
Amortization of prior service cost (credit)	(1)	(1)	(2)	(2)
Amortization of net actuarial loss	8	4	17	9
Net periodic benefit cost	42	39	87	79
Postretirement Medical
Net periodic benefit cost:
Service cost	0	0	0	0
Interest cost	22	14	44	28
Amortization of prior service cost (credit)	0	0	0	0
Amortization of net actuarial loss	47	0	94	0
Net periodic benefit cost	$ 69	$ 14	$ 138	$ 28