Accounts payable and accrued liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Payables and Accruals [Abstract]
Accounts payable	$ 3,236	$ 2,104
Accrued expenses	5,785	5,311
Accrued compensation and benefits	1,762	2,352
Other current liabilities	33	31
Total accounts payable and accrued liabilities	$ 10,816	$ 9,798