Other Income - Schedule of Other Income Net (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Other Income and Expenses [Abstract]
Change in fair value of derivative liability		$ 23		$ 73
Foreign exchange (losses) gain	$ (12)	6	$ (20)	(20)
Interest income	250	128	484	249
Miscellaneous (expenses) income	(9)	7	(29)	(15)
Other income (expenses)	$ 229	$ 164	$ 435	$ 287