Note 12 - Stock Warrants
|9 Months Ended|
Sep. 30, 2021
|Notes to Financial Statements|
|Stock Warrants Disclosure [Text Block]||
As of September 30, 2021, there are 972,324 warrants outstanding to purchase Navidea's Common Stock. The warrants are exercisable at prices ranging from $0.20 to $49.80 per share with a weighted average exercise price of $17.97 per share. The warrants have remaining outstanding terms ranging from 5 months to 13.9 years.