Other Income (Expenses) - Schedule of Other Income (Expenses) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other Income and Expenses [Abstract]
Change in fair value of derivative liability	$ 81	$ (52)	$ 949
Foreign exchange losses	(13)	(476)	(361)
Interest income	619	108	91
Miscellaneous	(43)	(100)	4
Other income (expenses)	$ 644	$ (520)	$ 683