General form of registration statement for all companies including face-amount certificate companies

Stock-Based Compensation (Details)

v3.21.2
Stock-Based Compensation (Details) - shares
shares in Thousands
9 Months Ended 12 Months Ended
Apr. 19, 2021
Sep. 30, 2021
Dec. 31, 2020
Sep. 20, 2017
2021 Omnibus Equity Incentive Plan        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Number of shares authorized 30,000      
Share-based compensation arrangement by share-based payment award, annual increase in shares authorized as a percentage of outstanding common shares 5.00%      
2017 Equity Plan        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Number of shares authorized       22,182
Term of award   10 years 10 years  
Stock options        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period   4 years 4 years  
Restricted Stock Units (RSUs)        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period   4 years 2 years