Balance Sheet Components (Details 1) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Components of accumulated other comprehensive loss
Foreign currency translation adjustment, net of tax of $46 and $10	$ (1,764)	$ (4,287)
Accumulated other comprehensive loss	(1,764)	(4,287)
Foreign currency translation adjustment, tax	$ 46	$ 10