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

Capitalization and Management Incentive Units - Class B Units (Details)

v3.21.4
Capitalization and Management Incentive Units - Class B Units (Details)
$ in Millions
 9 Months Ended 12 Months Ended
Sep. 30, 2021
USD ($)
shares
Dec. 31, 2020
USD ($)
shares
Dec. 31, 2019
shares
Dec. 31, 2018
shares
Preferred Units [Line Items]        
Number of tranches of units 5,647,438      
Number of units unvested 60,000 950,000 1,125,000 500,000
Class B Preferred Units [Member]        
Preferred Units [Line Items]        
Units authorized 19,701,492 19,701,492 19,701,492 19,701,492
Units issued 19,701,492 19,701,492    
Units outstanding   19,701,492 19,701,492 19,701,492
Number of units vested 19,701,492 19,701,492    
Class B-1 Preferred Units        
Preferred Units [Line Items]        
Number of tranches of units 10,000,000 10,000,000    
Vesting percentage 20.00% 20.00%    
Number of units vested 8,000,000 6,000,000 4,000,000 2,000,000
Number of units unvested 2,000,000 4,000,000    
Class B-2 Preferred Units        
Preferred Units [Line Items]        
Number of tranches of units 4,054,054 4,054,054    
Vesting percentage 1.00% 100.00%    
Minimum EBITDA for vesting of 100% units | $ $ 20 $ 20    
Minimum net proceeds distributable among the Members for vesting of 100% units | $ $ 200 $ 200    
Class B-3 Preferred Units        
Preferred Units [Line Items]        
Number of tranches of units   5,647,438    
Vesting percentage 1.00% 100.00%    
Minimum EBITDA for vesting of 100% units | $ $ 30 $ 30    
Minimum net proceeds distributable among the Members for vesting of 100% units | $ $ 300 $ 300