Quarterly report pursuant to Section 13 or 15(d)

Equity Incentive Plan - Additional Information (Details)

v3.19.2
Equity Incentive Plan - Additional Information (Details) - USD ($)
6 Months Ended 12 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2010
Jul. 10, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized $ 1,122,000 $ 805,000    
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition 2 years 1 year 6 months 26 days    
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding And Exercisable Intrinsic Value $ 0 $ 0    
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant 750,000 275,500    
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized     891,222  
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period     10 years  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value $ 368,200 $ 151,200    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value $ 0.47 $ 0.55    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period 17,819 0    
One-year anniversary [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage 0.33%      
24-month period [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage 0.67%      
Holders Owing More Than Ten Percentage Voting Rights [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period     5 years  
Holders Owing More Than Ten Percentage Voting Rights [Member] | Minimum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Percentage of Exercise Price     110.00%  
Equity Incentive Plan 2014 [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant 8,390,123      
Equity Incentive Plan 2014 [Member] | Maximum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant       8,390,123
ESPP [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant 117,090      
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized 170,567      
2014 Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant 4,033,056      
Excess Stock, Shares Authorized       350,000
Restricted Stock        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period 3,141