Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($)
$ in Thousands
6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Statement of Comprehensive Income [Abstract]    
Loss $ (9,415) $ (4,981)
Other comprehensive income (loss):    
Foreign currency translation adjustments (307) 1,002
Comprehensive loss $ (9,722) $ (3,979)