Other long-term liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Other Liabilities Disclosure [Abstract]
Liability for severance pay	$ 2,729	$ 2,624
Long-term portion of deferred revenue	1,036	1,330
Other	81	350
Total other long-term liabilities	$ 3,846	$ 4,304