EMPLOYEE BENEFIT PLANS - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Postretirement Medical Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost with interest to end of year	$ 87	$ 68	$ 63
Interest cost	23	26	39
Amortization of prior service cost	74	74	74
Amortization of gain	(24)	(50)	(46)
Total net periodic benefit cost	160	118	130
Pension Plan | Chemogas Defined Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost with interest to end of year	67	104	0
Interest cost	14	20	0
Expected return on plan assets	(34)	(14)	0
Amortization of prior service cost	0	0	0
Amortization of gain	3	0	0
Total net periodic benefit cost	$ 50	$ 110	$ 0