Annual report pursuant to Section 13 and 15(d)

Note 1 - Organization and Summary of Significant Accounting Policies (Details Textual)

v3.19.1
Note 1 - Organization and Summary of Significant Accounting Policies (Details Textual) - USD ($)
 1 Months Ended 12 Months Ended
Mar. 03, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2019
Jan. 01, 2018
Notes Payable, Fair Value Disclosure     $ 316,000 $ 2,400,000    
Notes Payable, Current, Total     316,074 2,353,639    
Derivative Liability, Total     $ 63,000 63,000    
Class of Warrant or Right, Exercise Price of Warrants or Rights [1]     $ 1.15      
Impairment of Long-Lived Assets to be Disposed of     $ 0 0    
Unrecognized Tax Benefits, Ending Balance     $ 0 0    
Open Tax Year     2015 2016 2017 2018      
Deferred Revenue           $ 726,061
Cumulative Effect of New Accounting Principle in Period of Adoption       (700,000)    
Accounting Standards Update 2014-09 [Member] | Sayre Pharmaceuticals [Member]            
Deferred Revenue           700,000
Cumulative Effect of New Accounting Principle in Period of Adoption           $ 700,000
Accounting Standards Update 2016-18 [Member] | Previously Reported [Member]            
Prior Period Reclassification Adjustment     $ 5,000,000      
Accounting Standards Update 2016-02 [Member] | Scenario, Forecast [Member]            
Operating Lease, Right-of-Use Asset         $ 286,000  
Operating Lease, Liability, Total         $ 286,000  
Minimum [Member]            
Class of Warrant or Right, Exercise Price of Warrants or Rights     $ 0.01      
Finite-Lived Intangible Asset, Useful Life     5 years      
Maximum [Member]            
Class of Warrant or Right, Exercise Price of Warrants or Rights     $ 2.50      
Finite-Lived Intangible Asset, Useful Life     15 years      
The 2002 Plan [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized     12,000,000      
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant     0      
The 2014 Plan [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized     15,000,000      
The 2002 and 2014 Plan [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period     10 years      
The 2002 and 2014 Plan [Member] | Minimum [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period     1 year      
The 2002 and 2014 Plan [Member] | Maximum [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period     4 years      
Series NN Warrants [Member]            
Class of Warrant or Right, Term   5 years        
Class of Warrant or Right, Exercise Price of Warrants or Rights   $ 1.50 $ 1.50      
Series NN Warrants [Member] | Cardinal Health 414 [Member]            
Class of Warrant or Right, Number of Securities Called by Warrants or Rights   10,000,000        
Class of Warrant or Right, Grants in Period, Estimated Fair Value       $ 3,300,000    
Series NN Warrants [Member] | UCSD [Member]            
Class of Warrant or Right, Term 5 years          
Class of Warrant or Right, Number of Securities Called by Warrants or Rights 1,000,000 1,000,000   1,000,000    
Class of Warrant or Right, Exercise Price of Warrants or Rights $ 1.50          
Class of Warrant or Right, Grants in Period, Estimated Fair Value   $ 334,000   $ 334,000    
Navidea Biopharmaceuticals Limited [Member]            
Noncontrolling Interest, Ownership Percentage by Parent     100.00%      
[1] Weighted average exercise price.