Schedule of proceeds of equity components based on fair value (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)
Gross proceeds of units	$ 3,200
Transaction costs of units	328
Net proceeds of units	2,872
Common stock
Gross proceeds of units	1,627
Transaction costs of units	167
Net proceeds of units	1,460
Warrants
Gross proceeds of units	487
Transaction costs of units	50
Net proceeds of units	437
Public Offering
Gross proceeds of units	12,634
Transaction costs of units	2,011
Net proceeds of units	10,623
Public Offering | Common stock
Gross proceeds of units	10,926
Transaction costs of units	1,739
Net proceeds of units	9,187
Public Offering | Warrants
Gross proceeds of units	1,708
Transaction costs of units	272
Net proceeds of units	$ 1,436