PENSION AND OTHER POSTRETIREMENT PLANS - Components of net periodic benefit cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net pension expense:
Net (gain) loss	$ (115)	$ (390)	$ 105
Pension Benefits
Net pension expense:
Service cost	0	0	0
Interest cost	53	52	75
Expected return on plan assets	(130)	(133)	(140)
Recognized net actuarial (gain) loss	99	160	171
Settlement cost	23	65	115
Net pension expense	45	144	221
Net (gain) loss	(215)	(350)	69
Amortization of net loss	(99)	(160)	(171)
Total recognized in other comprehensive income (loss)	(314)	(510)	(102)
Total recognized in net pension expense and other comprehensive income (loss)	$ (269)	$ (366)	$ 119
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent
SERP Benefits
Net pension expense:
Service cost	$ 0	$ 0	$ 0
Interest cost	20	18	27
Expected return on plan assets	(45)	(47)	(51)
Recognized net actuarial (gain) loss	45	82	80
Settlement cost	0	0	0
Net pension expense	20	53	56
Net (gain) loss	100	(40)	36
Amortization of net loss	(45)	(82)	(80)
Total recognized in other comprehensive income (loss)	55	(122)	(44)
Total recognized in net pension expense and other comprehensive income (loss)	$ 75	$ (69)	$ 12
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent