Note 6 - Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accrued expenses	$ 226	$ 129
Accrued employee costs	455	410
Grant liability	666	663
Customer deposits	83	61
Total	$ 1,430	$ 1,263