RETIREMENT PLANS (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Pension Plan
Net periodic benefit cost:
Service cost	$ 53	$ 72
Interest cost	89	87
Expected return on plan assets	(147)	(141)
Amortization of prior service cost (credit)	1	1
Amortization of net actuarial loss	21	41
Net periodic benefit cost	17	60
Other disclosures
Defined Benefit Plans, Estimated Future Employer Contributions	500
SERP
Net periodic benefit cost:
Service cost	6	16
Interest cost	15	21
Amortization of prior service cost (credit)	(1)	(1)
Amortization of net actuarial loss	0	9
Net periodic benefit cost	20	45
Postretirement Medical
Net periodic benefit cost:
Service cost	0	0
Interest cost	19	22
Amortization of prior service cost (credit)	0	0
Amortization of net actuarial loss	3	47
Net periodic benefit cost	$ 22	$ 69