RETIREMENT AND DEFERRED COMPENSATION PLANS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
United States
Change in benefit obligation:
Service cost	$ 3,577	$ 2,773
Interest cost	1,987	1,845
Change in plan assets:
Employer contribution	204
Components of net periodic benefit cost:
Service cost	3,577	2,773
Interest cost	1,987	1,845
Expected return on plan assets	(3,422)	(3,094)
Amortization of net loss	1,548	489
Net periodic benefit cost	3,690	2,013
Minimum funding requirements	0
Expected contribution in current fiscal year	200
Foreign Plans
Change in benefit obligation:
Service cost	1,768	1,460
Interest cost	340	501
Change in plan assets:
Employer contribution	711
Components of net periodic benefit cost:
Service cost	1,768	1,460
Interest cost	340	501
Expected return on plan assets	(634)	(592)
Amortization of net loss	514	363
Amortization of prior service cost	97	113
Net periodic benefit cost	$ 2,085	$ 1,845