EMPLOYEE BENEFIT PLANS - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Postretirement Medical Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost with interest to end of year	$ 108	$ 79	$ 87
Interest cost	62	26	23
Amortization of prior service cost	0	9	74
Amortization of loss (gain)	8	(2)	(24)
Total net periodic benefit cost	178	112	160
Pension Plan | Chemogas Defined Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost with interest to end of year	65	44	67
Interest cost	65	17	14
Expected return on plan assets	(42)	(37)	(34)
Amortization of loss (gain)	0	0	3
Total net periodic benefit cost	$ 88	$ 24	$ 50