RETIREMENT AND DEFERRED COMPENSATION PLANS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Domestic Plans
Change in benefit obligation:
Service cost	$ 2,426	$ 2,261	$ 7,279	$ 6,781
Interest cost	1,752	1,694	5,257	5,082
Change in plan assets:
Employer contribution			24,700
Components of net periodic benefit cost:
Service cost	2,426	2,261	7,279	6,781
Interest cost	1,752	1,694	5,257	5,082
Expected return on plan assets	(2,470)	(2,118)	(7,409)	(6,353)
Amortization of net loss	801	820	2,403	2,462
Net periodic benefit cost	2,509	2,657	7,530	7,972
Minimum funding requirements			0
Foreign Plans
Change in benefit obligation:
Service cost	1,447	1,148	4,166	3,449
Interest cost	459	477	1,321	1,432
Change in plan assets:
Employer contribution			2,000
Components of net periodic benefit cost:
Service cost	1,447	1,148	4,166	3,449
Interest cost	459	477	1,321	1,432
Expected return on plan assets	(627)	(550)	(1,781)	(1,651)
Amortization of net loss	493	388	1,400	1,165
Amortization of prior service cost	104	89	296	265
Net periodic benefit cost	1,876	$ 1,552	5,402	$ 4,660
Expected contribution in current fiscal year	$ 2,500		$ 2,500