EMPLOYEE BENEFIT PLANS (Details) $ in Thousands		3 Months Ended		12 Months Ended
	Jan. 01, 2021 numberOfPlan	Mar. 31, 2021 USD ($) numberOfPlan	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) numberOfPlan
Defined Benefit Plan Disclosure [Line Items]
Number of savings plan | numberOfPlan	1			2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		$ 22	$ 17
Interest cost		6	6
Amortization of prior service cost		18	19
Amortization of gain		(6)	(13)
Net periodic benefit cost		40	29
Benefit obligation		1,402		$ 1,374
Deferred compensation liability		5,420		3,581
Related rabbi trust assets		5,319		3,581
Maximum
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Historical cash payments for retirement medical plan claims per year		$ 100
Postretirement Medical Plan
Defined Benefit Plan Disclosure [Line Items]
Number of defined benefit plans | numberOfPlan		2
Defined Benefit Pension Plan | Chemogas Defined Pension Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		$ 17	26
Interest cost		4	5
Expected return on plan assets		(9)	(4)
Amortization of gain		1	0
Net periodic benefit cost		13	$ 27
Benefit obligation		$ 920		$ 950