RETIREMENT PLANS (Details) - USD ($)	1 Months Ended	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Retirement plans
Curtailment gain, net of taxes of $0		$ 1,699,000	$ 0
Other disclosures
Net actuarial gains arising during the period		880,000	0
Reduction in unrecognized benefit costs previously included in AOCL		(60,000)	(17,000)
Pension Plan
Net periodic benefit cost:
Service cost		50,000	50,000
Interest cost		83,000	93,000
Expected return on plan assets		(163,000)	(161,000)
Amortization of prior service cost (credit)		1,000	1,000
Amortization of net actuarial loss		35,000	3,000
Curtailment cost (income)		53,000	0
Net periodic benefit cost (income)		59,000	(14,000)
Other disclosures
Estimated future Pension Plan contributions	$ 0	0
SERP
Net periodic benefit cost:
Service cost		3,000	9,000
Interest cost		18,000	21,000
Expected return on plan assets		0	0
Amortization of prior service cost (credit)		(1,000)	(1,000)
Amortization of net actuarial loss		5,000	1,000
Curtailment cost (income)		(53,000)	0
Net periodic benefit cost (income)		(28,000)	30,000
Postretirement Medical
Net periodic benefit cost:
Service cost		0	0
Interest cost		20,000	25,000
Expected return on plan assets		0	0
Amortization of prior service cost (credit)		0	0
Amortization of net actuarial loss		20,000	13,000
Curtailment cost (income)		0	0
Net periodic benefit cost (income)		40,000	$ 38,000
Pension Plan and SERP
Retirement plans
Curtailment gain, net of taxes of $0	1,699,000
Other disclosures
Net actuarial gains arising during the period		$ 880,000
Reduction in unrecognized benefit costs previously included in AOCL	$ 1,699,000