XML 52 R41.htm IDEA: XBRL DOCUMENT v3.21.2
Stockholders' Equity - Stock Options (Details) - 2017 Plan - shares
9 Months Ended 12 Months Ended
Sep. 30, 2021
Dec. 31, 2020
Jan. 01, 2021
Sep. 08, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expiration period 10 years      
Options to purchase common stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Maximum shares authorized (in shares)       400,000
Expiration period 10 years      
Percentage increase of authorized shares     4.00%  
Annual additional options authorized (in shares) 101,857 170,324    
Options to purchase common stock | Maximum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award vesting period 4 years      
Options to purchase common stock | Minimum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award vesting period 1 year