Long-term liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Other Liabilities Disclosure [Abstract]
Liability for social contribution	$ 2,643	$ 2,729
Long-term portion of deferred revenue	797	1,036
Other	38	81
Total Long-term liabilities	$ 3,478	$ 3,846