RETIREMENT PLANS - Schedule of post-retirement benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Change in benefit obligation:
Benefit obligation at January 1	$ 106,496	$ 109,922
Service cost	1,190	1,355	$ 1,300
Interest cost	2,826	2,632	3,116
Actuarial (gain) loss	(21,350)	(2,943)
Benefit obligation at December 31	83,578	106,496	109,922
Funded status at December 31	(11,844)	(18,517)
Supplemental Employee Retirement Plans, Defined Benefit
Change in benefit obligation:
Benefit obligation at January 1	4,015	4,147
Service cost	34	43
Interest cost	111	103
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant	74	34
Actuarial (gain) loss	(758)	(53)
Defined Benefit Plan, Benefit Obligation, Benefits Paid	301	259
Benefit obligation at December 31	3,175	4,015	$ 4,147
Funded status at December 31	$ 3,175	$ 4,015