XML 51 R39.htm IDEA: XBRL DOCUMENT v3.20.2
Stock-based Payments - Narrative (Details) - USD ($)
12 Months Ended
Dec. 12, 2013
Feb. 18, 2011
Apr. 30, 2020
Apr. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense     $ 600,000 $ 649,000
Modification expense     $ 56,529  
Stock options award shares to purchase common stock 16,667      
Grants in period, weighted average grant date fair value (in dollars per share)     $ 5.33 $ 6.03
Shares granted (in shares)     229,833 206,790
Grants in period, weighted average exercise price (in dollars per share)     $ 5.33 $ 9.86
Warrants outstanding (in shares)     0  
Proceeds from warrant exercises     $ 3,900,000  
Stock issued during period shares stock options and warrants exercised (in shares)     161,000  
Equity Incentive Plan 2010        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expiration term of awards     10 years  
Strike price as percent of market value     100.00%  
Equity Incentive Plan 2010 | Maximum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Shares granted, net of forfeitures (in shares)   30,000,000    
2008 Equity Incentive Plan        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expiration term of awards     10 years  
Director Compensation Plan        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock options award shares to purchase common stock 8,333      
Stock option award shares to purchase unregistered common stock 1,667      
Vested percent 25.00%      
Board of Directors Chairman | Director Compensation Plan        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Term of option to purchase     5 years  
General and administrative        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense     $ 328,000 $ 458,000
Expense for service performed     $ 0 $ 6,000