RETIREMENT AND DEFERRED COMPENSATION PLANS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
United States
Change in benefit obligation:
Service cost	$ 3,562	$ 2,775	$ 7,139	$ 5,548
Interest cost	1,536	1,846	3,523	3,691
Change in plan assets:
Employer contribution			204
Components of net periodic benefit cost:
Service cost	3,562	2,775	7,139	5,548
Interest cost	1,536	1,846	3,523	3,691
Expected return on plan assets	(2,702)	(3,095)	(6,124)	(6,189)
Amortization of net loss	1,294	489	2,842	978
Net periodic benefit cost	3,690	2,015	7,380	4,028
Minimum funding requirements			0
Expected contribution in current fiscal year	200		200
Foreign Plans
Change in benefit obligation:
Service cost	1,767	1,445	3,535	2,905
Interest cost	340	495	680	996
Change in plan assets:
Employer contribution			1,100
Components of net periodic benefit cost:
Service cost	1,767	1,445	3,535	2,905
Interest cost	340	495	680	996
Expected return on plan assets	(631)	(586)	(1,265)	(1,178)
Amortization of net loss	514	359	1,028	722
Amortization of prior service cost	95	113	192	226
Net periodic benefit cost	$ 2,085	$ 1,826	$ 4,170	$ 3,671