CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
NET INCOME	$ 15,400	$ 5,126
OTHER COMPREHENSIVE (LOSS) INCOME, NET OF TAX:
Defined benefit pension plan adjustments	247
Foreign currency translation adjustment	930	(588)
Unrealized (loss) gain in fair value of investments	8	(10)
Unrealized (loss) gain in fair value of interest rate swap	(35)	45
Total other comprehensive (loss) income, net of tax	1,150	(553)
TOTAL COMPREHENSIVE INCOME	$ 16,550	$ 4,573