Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 928	$ 2,489	$ 8,987	$ 9,582
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale securities, net of income tax expense (benefit) of $11, $(5), $(7) and $(17)	34	(9)	(3)	(28)
Gain (loss) on derivative securities, effective portion, net of income tax expense (benefit) of $4, $(7), $32 and $65	12	(12)	156	107
Foreign currency translation, net of income tax expense of $3, $2, $0 and $2	(338)	330	(455)	401
Net other comprehensive income (loss) during period	(292)	309	(302)	480
Comprehensive income	$ 636	$ 2,798	$ 8,685	$ 10,062