RETIREMENT PLANS - Net Periodic Pension Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Components of the plan's net periodic pension cost
Settlements	$ 369	$ 1,725
Pension benefits
Components of the plan's net periodic pension cost
Service cost	90	151	$ 229
Interest cost	3,323	2,373	2,043
Expected return on plan assets	(2,936)	(3,814)	(3,366)
Amortization of actuarial (gain) loss	(43)
Settlements		1,725	34
Net periodic pension cost	434	435	(1,060)
Postretirement benefits
Components of the plan's net periodic pension cost
Service cost	65	124	143
Interest cost	182	139	127
Amortization of actuarial (gain) loss	(113)
Net periodic pension cost	$ 134	$ 263	$ 270