RETIREMENT PLANS (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended			9 Months Ended
	Dec. 31, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Retirement plans
Curtailment gain, net of taxes of $0		$ 0		$ 0	$ 1,699	$ 0
Other disclosures
Net actuarial gains arising during the period		0		0	880	0
Reduction in unrecognized benefit costs previously included in AOCI		(20)		(9)	(100)	(42)
Pension Plan
Net periodic benefit cost:
Service cost		0		41	50	141
Interest cost		73		92	228	279
Expected return on plan assets		(173)		(165)	(508)	(486)
Amortization of prior service cost (credit)		0		2	1	5
Amortization of net actuarial loss		0		(3)	35	1
Curtailment cost (income)					53	0
Net periodic benefit (income) cost		(100)		(33)	(141)	(60)
Other disclosures
Estimated future Pension Plan contributions		0			0
SERP
Net periodic benefit cost:
Service cost		0		6	3	24
Interest cost		16		16	49	58
Amortization of prior service cost (credit)		0		(2)	(1)	(4)
Amortization of net actuarial loss		0		(1)	5	1
Curtailment cost (income)					(53)	0
Net periodic benefit (income) cost		16		19	3	79
Postretirement Medical
Net periodic benefit cost:
Service cost		0		0	0	0
Interest cost		20		25	60	75
Amortization of prior service cost (credit)		0		0	0	0
Amortization of net actuarial loss		20		13	60	39
Curtailment cost (income)					0	0
Net periodic benefit (income) cost		$ 40		$ 38	$ 120	$ 114
Pension Plan And SERP
Retirement plans
Curtailment gain, net of taxes of $0	$ 1,699
Other disclosures
Net actuarial gains arising during the period			$ 880
Reduction in unrecognized benefit costs previously included in AOCI	$ 1,699