EMPLOYEE BENEFIT PLANS (Details) $ in Thousands			9 Months Ended
	May 27, 2019 plan	Dec. 31, 2018 USD ($) plan	Sep. 30, 2019 USD ($) plan	Sep. 30, 2018 USD ($)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost			$ 47	$ 58
Interest cost			29	33
Amortization of prior service cost			55	52
Amortization of gain			(34)	(2)
Net periodic benefit cost			97	$ 141
Benefit obligation		$ 1,174	1,250
Unfunded, Nonqualified Deferred Compensation Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Deferred compensation liability		265	1,803
Maximum
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Historical cash payments for retirement medical plan claims per year			100
Level 1
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Related rabbi trust assets		265	1,803
Level 1 | Other Noncurrent Assets
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Related rabbi trust assets		$ 265	1,803
Chemogas
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Benefit obligation			$ 580
Postretirement Medical Plan
Defined Benefit Plan Disclosure [Line Items]
Number of defined benefit plans | plan			2
Defined Benefit Pension Plan | Chemogas
Defined Benefit Plan Disclosure [Line Items]
Number of defined benefit plans | plan	2
Number of defined benefit plans closed | plan		1
Number of defined contribution plans | plan		4