Accounts payable and accrued liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Payables and Accruals [Abstract]
Accounts payable	$ 4,445	$ 2,104
Accrued expenses	7,002	5,311
Accrued compensation and benefits	2,307	2,352
Other current liabilities	36	31
Total accounts payable and accrued liabilities	$ 13,790	$ 9,798