OTHER INCOME, NET (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
OTHER INCOME, NET:
Interest and dividend income	$ 2,130	$ 1,421	$ 1,582
Gains on trading securities relating to deferred compensation plans	4,275	1,450	4,901
Interest expense	(105)	(76)	(99)
Pretax gain on step acquisition			1,821
Foreign exchange gains (losses)	(955)	(1,427)	(861)
Capital gains (losses)	7	2	(219)
Miscellaneous, net	146	126	246
Total other income, net	$ 5,498	$ 1,496	$ 7,371