XML 33 R21.htm IDEA: XBRL DOCUMENT v3.21.1
Note 3 - Basis of Presentation and Summary of Significant Accounting Policies - Outstanding Dilutive Securities (Details) - shares
3 Months Ended
Mar. 31, 2021
Mar. 30, 2020
Anti-dilutive securities (in shares) 9,822,858 22,541,799
Warrant [Member]    
Anti-dilutive securities (in shares) 6,553,039 21,261,070
Share-based Payment Arrangement, Option [Member]    
Anti-dilutive securities (in shares) 3,116,819 1,182,629
Restricted Stock [Member]    
Anti-dilutive securities (in shares) 153,000 98,100