CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME [Abstract]
Net (loss) earnings	$ (11,897)	$ (64,834)	$ 19,197
Other comprehensive income (loss):
Currency translation adjustment, net of taxes of $183, ($648) and ($194)	12,439	(9,671)	(9,954)
Unrealized holding (losses) gains on marketable securities arising during the period, net of taxes of ($177), ($2) and $5	(279)	(10)	5
Change in unfunded SERP liability, net of taxes of $237, $71 and $2, respectively	(488)	260	21
Other comprehensive income (loss):	11,672	(9,421)	(9,928)
Comprehensive (loss) income	$ (225)	$ (74,255)	$ 9,269