XML 83 R61.htm IDEA: XBRL DOCUMENT v3.20.4
Equity Plans - Narrative (Details) - shares
1 Months Ended 12 Months Ended
Jul. 31, 2016
Dec. 31, 2020
Dec. 31, 2018
Dec. 31, 2019
May 31, 2018
Equity Plans          
Average volatility   75.00%      
Percentage of volatility of stock options since IPO   25.00%      
2007 Stock Option and Incentive Plan          
Equity Plans          
Number of shares available for issuance 0        
2016 Equity Incentive Plan          
Equity Plans          
Number of shares authorized 1,200,000        
Maximum annual additional authorized shares as a percentage of outstanding shares   4.00%      
Number of shares available for issuance       538,374  
2016 Equity Incentive Plan | Stockholders possessing more than 10% of the total combined voting power | Minimum          
Equity Plans          
Exercise price as a percentage of the fair market value of common stock on grant date   110.00%      
2016 Equity Incentive Plan | Tranche two          
Equity Plans          
Vesting period 4 years        
Restricted stock unit incentive awards granted in 2018          
Equity Plans          
Expiration period   10 years      
Vesting period     18 months    
Number of shares authorized         750,000
Number of shares available for issuance   574,375      
Stock options - employees, consultants, directors | 2007 Stock Option and Incentive Plan          
Equity Plans          
Expiration period   10 years      
Stock options - employees, consultants, directors | 2007 Stock Option and Incentive Plan | Minimum          
Equity Plans          
Vesting period   4 years      
Stock options - employees, consultants, directors | 2016 Equity Incentive Plan          
Equity Plans          
Expiration period   10 years      
Stock options - employees, consultants, directors | 2016 Equity Incentive Plan | Minimum          
Equity Plans          
Exercise price as a percentage of the fair market value of common stock on grant date   100.00%      
Non Employee Director Initial Stock Options | 2016 Equity Incentive Plan | Maximum          
Equity Plans          
Vesting period   3 years      
Nonemployee Director Annual Refresher Stock Options | 2016 Equity Incentive Plan | Minimum          
Equity Plans          
Vesting period   1 year