Quarterly report pursuant to Section 13 or 15(d)

Note 2 - Summary of Significant Accounting Policies - Antidilutive Securities (Details)

v3.10.0.1
Note 2 - Summary of Significant Accounting Policies - Antidilutive Securities (Details) - shares
6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Employee Stock Option [Member]    
Stock options to purchase common stock (in shares) 4,209,355 2,287,572
Common Stock Warrants [Member]    
Stock options to purchase common stock (in shares) 642,622 642,622
Restricted Stock [Member]    
Stock options to purchase common stock (in shares) 66,250 6,250