EMPLOYEE BENEFIT PLANS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Company-administered plans:
Contribution to pension plans	$ 1,000
Expected plan contributions	7,000
Pension Plan
Company-administered plans:
Net pension expense	2,947	$ 7,163
Pension Plan | Company-administered plans
Company-administered plans:
Service cost	368	3,213
Interest cost	14,535	17,532
Expected return on plan assets	(21,694)	(24,263)
Prior service cost	7,097	7,902
Net pension expense	306	4,384
Pension Plan | Company-administered plans | U.S.
Company-administered plans:
Net pension expense	2,363	6,778
Pension Plan | Company-administered plans | Non-U.S.
Company-administered plans:
Net pension expense	(2,057)	(2,394)
Pension Plan | Multi-employer plans
Company-administered plans:
Net pension expense	$ 2,641	$ 2,779