Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation - Narrative (Details)

v3.22.1
Stock-Based Compensation - Narrative (Details)
 3 Months Ended 12 Months Ended
Dec. 31, 2021
USD ($)
$ / shares
shares
Sep. 30, 2021
office
$ / shares
shares
Jun. 30, 2021
$ / shares
shares
Mar. 31, 2021
$ / shares
shares
Dec. 31, 2020
USD ($)
$ / shares
shares
Sep. 30, 2020
$ / shares
shares
Jun. 30, 2020
$ / shares
shares
Mar. 31, 2020
$ / shares
shares
Dec. 31, 2021
USD ($)
purchasePeriod
$ / shares
shares
Dec. 31, 2020
USD ($)
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Granted (in shares)   50,000             0 0
Granted (in dollars per share) | $ / shares   $ 1.08             $ 0 $ 0
Restricted Stock Units (RSUs) - Non-Employee Directors                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Restricted stock unit awards granted (in shares) 368,672       50,000 39,426        
Restricted stock unit awards grant date fair value (in dollars per share) | $ / shares $ 1.35         $ 1.28     1.35  
Restricted Stock Units (RSUs) - Non-Employee Directors | Share-based Payment Arrangement, Tranche One                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Restricted stock unit awards granted (in shares)       652,170     85,996 123,084    
Restricted stock unit awards grant date fair value (in dollars per share) | $ / shares       $ 1.22     $ 0.71 $ 1.25    
Restricted Stock Units (RSUs) - Non-Employee Directors | Share-based Payment Arrangement, Tranche Two                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Restricted stock unit awards granted (in shares)       97,744     375,000 125,523    
Restricted stock unit awards grant date fair value (in dollars per share) | $ / shares       $ 1.22     $ 0.67 $ 1.25    
Vesting period of award             4 years      
Vesting percentage of award (as a percent)             25.00%      
Restricted Stock Units (RSUs) - Team Members                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Restricted stock unit awards granted (in shares) 170,000 54,000 54,000 3,488,262 30,000 12,000   746,000    
Restricted stock unit awards grant date fair value (in dollars per share) | $ / shares $ 3.97 $ 1.09 $ 1.23 $ 2.03   $ 1.68   $ 1.25 $ 3.97  
Vesting period of award 47 months 47 months 47 months   4 years 4 years   42 months    
Vesting percentage of award (as a percent)         25.00% 25.00%        
Restricted Stock Units (RSUs) - Team Members | Minimum                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Vesting period of award       10 months            
Restricted Stock Units (RSUs) - Team Members | Maximum                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Vesting period of award       51 months            
Restricted Stock Units (RSUs) - Non-Employees                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Restricted stock unit awards granted (in shares)           155,000 250,000 630,000    
Restricted stock unit awards grant date fair value (in dollars per share) | $ / shares         $ 0.85 $ 1.52 $ 0.67 $ 0.88   $ 0.85
Options                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Vesting period of award   1 year                
Number of equal monthly installments | office   12                
Aggregate intrinsic value of options | $ $ 1,168,000       $ 88,000       $ 1,168,000 $ 88,000
Total fair value for options | $                 $ 66,000 $ 130,000
2018 Equity Incentive Plan                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Issuance of common stock shares (in shares)                 925,467,000  
Common stock reserved for issuance (in shares) 762,038       2,551,720       762,038 2,551,720
Unrecognized compensation expense | $ $ 5,943,000               $ 5,943,000  
Amortization period of restricted stock cost                 2 years 8 months 12 days  
2018 Equity Incentive Plan | Employee Stock | Outstanding Shares on Last Day of Immediately Preceding Year                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Annual increase (in shares) 2,729,416               2,729,416  
Annual percentage increase 5.00%               5.00%  
2018 Employee Stock Purchase Plan                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Common stock reserved for issuance (in shares) 189,215       272,942       189,215 272,942
Maximum payroll deductions (as a percent) 15.00%               15.00%  
Maximum yearly contribution | $ $ 25,000               $ 25,000  
Maximum number of shares participant may purchase                 4,000  
Offering period                 24 months  
Number of purchase periods | purchasePeriod                 4  
Purchase period for award                 6 months  
ESPP, purchase price (as a percent)                 85.00%  
Unrecognized compensation expense | $ $ 328,000               $ 328,000  
Amortization period of restricted stock cost                 1 year 6 months  
2018 Employee Stock Purchase Plan | Maximum                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Common stock reserved for issuance (in shares) 272,942               272,942  
2018 Employee Stock Purchase Plan | Employee Stock                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Annual increase (in shares) 818,825               818,825  
Outstanding shares of common stock on last day of immediately preceding year (as a percent) 1.50%               1.50%  
2009 Equity Incentive Plan                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Vesting period of award                 4 years  
Expiration period                 10 years  
Unvested shares (in shares) 0       574       0 574
Accrued expenses | $         $ 1,000         $ 1,000
Unrecognized compensation expense | $ $ 14,000               $ 14,000  
Amortization period of restricted stock cost                 3 months 18 days