Consolidated Statements Of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 26,267	$ 34,178	$ 26,602
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Unrealized gain (loss) on marketable securities, net of income tax expense (benefit) of $(27), $5, and $1	(56)	8	2
Gain (loss) on derivative securities, effective portion, net of income tax expense (benefit) of $171, $(14), and $0	240	(24)	0
Foreign currency translation adjustment, net of income tax expense (benefit) of $1, $(5), and $17	774	126	(1,021)
Other comprehensive income (loss)	958	110	(1,019)
Comprehensive income	$ 27,225	$ 34,288	$ 25,583