EMPLOYEE BENEFIT PLANS (Details) $ in Thousands			9 Months Ended
	Jan. 01, 2021 plan	Dec. 31, 2020 USD ($) plan	Sep. 30, 2021 USD ($) plan	Sep. 30, 2020 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Number of savings plan | plan	1	2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Deferred compensation liability		$ 3,581	$ 6,077
Related rabbi trust assets		3,581	6,076
Level 1
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Related rabbi trust assets		3,581	$ 6,076
Postretirement Medical Plans
Defined Benefit Plan Disclosure [Line Items]
Number of defined benefit plans | plan			2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost			$ 65	$ 51
Interest cost			17	19
Amortization of prior service cost			55	56
Amortization of (gain) loss			(18)	(38)
Net periodic benefit cost			119	88
Benefit obligation		1,374	1,456
Historical cash payments for retirement medical plan claims per year (less than)			100
Defined Benefit Pension Plans | Chemogas Defined Pension Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost			52	78
Interest cost			11	15
Expected return on plan assets			(26)	(12)
Amortization of (gain) loss			2	0
Net periodic benefit cost			39	$ 81
Benefit obligation		$ 950	$ 934