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 loss	$ (18,853)	$ (6,505)	$ (23,971)
Change in cumulative foreign currency translation adjustment	10,695	(1,049)	(13,869)
Total comprehensive loss	$ (8,158)	$ (7,554)	$ (37,840)