Consolidated Statements Of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) [Abstract]
Net income (loss)	$ 1,312	$ 11,562	$ (2,089)
Other comprehensive income (loss), before tax:
Foreign currency translation adjustments	738	(383)	(625)
Unrealized losses on available-for-sale securities:
Unrealized losses	(3)	(8)	(78)
Total unrealized losses on available-for-sale securities	(3)	(8)	(78)
Unrealized gains (losses) on foreign exchange forward contracts:
Unrealized gains (losses)	0	53	(298)
Reclassification adjustment for losses included in net income (loss)	0	36	563
Total unrealized gains on foreign exchange forward contracts	0	89	265
Other comprehensive income (loss), before tax	735	(302)	(438)
Income tax provision (benefit) related to items of other comprehensive income (loss)	204	(71)	0
Other comprehensive income (loss), net of tax	531	(231)	(438)
Total comprehensive income (loss)	$ 1,843	$ 11,331	$ (2,527)