CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 15,886	$ 7,233
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of $0 tax in each of the three months ended March 31, 2020 and 2019	(283)	(22)
Unrealized gain (loss) on marketable securities, net of $0 tax in each of the three months ended March 31, 2020 and 2019	(952)	334
Amortization of defined benefit pension items, net of tax of $31 and $5 in the three months ended March 31, 2020, and 2019, respectively	51	16
Total other comprehensive income (loss)	(1,184)	328
TOTAL COMPREHENSIVE INCOME	$ 14,702	$ 7,561