Quarterly report pursuant to Section 13 or 15(d)

Note 11 - Stock-based Compensation (Details Textual)

v3.21.1
Note 11 - Stock-based Compensation (Details Textual) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended
Jul. 10, 2020
May 05, 2020
Mar. 10, 2020
Mar. 31, 2021
Mar. 31, 2020
Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Subscription Rate           17.50%
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares (in shares)           15,600,000
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)       4 years    
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)       10 years    
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount       $ 11,030    
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)       1 year 299 days    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number (in shares)       7,887,000 3,990,000  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price (in dollars per share)       $ 4.59 $ 2.96  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term (Month)       5 years 346 days 6 years 292 days  
Share-based Payment Arrangement, Expense       $ 6,643 $ 4,401  
Restricted Stock Units (RSUs) [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)   120 days 90 days      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)     645,000 645,000  
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures, Total (in shares) 645,000          
Officer [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number (in shares)       1,679,169    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term (Month)       1 year    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Remaining Contractual Term (Month)       1 year    
Officer [Member] | Continuing Vesting Options with No Service Requirement [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Accelerated Vesting, Number (in shares)       504,833    
Officer [Member] | Vested Options [Member]            
Share-based Payment Arrangement, Expense       $ 945    
Officer [Member] | Unvested Options [Member]            
Share-based Payment Arrangement, Expense       $ 663    
Officer [Member] | Minimum [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price (in dollars per share)       $ 1.03    
Officer [Member] | Maximum [Member]            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price (in dollars per share)       $ 7.44