RETIREMENT AND DEFERRED COMPENSATION PLANS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
United States
Change in benefit obligation:
Service cost	$ 2,775	$ 2,844	$ 5,548	$ 5,693
Interest cost	1,846	1,706	3,691	3,426
Change in plan assets:
Employer contribution			365
Components of net periodic benefit cost:
Service cost	2,775	2,844	5,548	5,693
Interest cost	1,846	1,706	3,691	3,426
Expected return on plan assets	(3,095)	(2,792)	(6,189)	(5,606)
Amortization of net loss	489	1,210	978	2,428
Net periodic benefit cost	2,015	2,968	4,028	5,941
Minimum funding requirements			0
Foreign Plans
Change in benefit obligation:
Service cost	1,445	1,491	2,905	3,022
Interest cost	495	457	996	929
Change in plan assets:
Employer contribution			1,100
Components of net periodic benefit cost:
Service cost	1,445	1,491	2,905	3,022
Interest cost	495	457	996	929
Expected return on plan assets	(586)	(658)	(1,178)	(1,337)
Amortization of net loss	359	433	722	879
Amortization of prior service cost	113	125	226	254
Net periodic benefit cost	1,826	$ 1,848	3,671	$ 3,747
Expected contribution in current fiscal year	$ 4,300		$ 4,300