v3.24.3
Restructuring - Summary of Restructuring Costs (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2024
Sep. 30, 2023
Sep. 30, 2024
Sep. 30, 2023
Restructuring Cost And Reserve [Line Items]        
Restructuring Costs $ 12 $ 15 $ 45 $ 63
Inception to Date 133   133  
Estimated Remaining Costs 6   6  
Estimated Total Cost 139   139  
Employer Solutions        
Restructuring Cost And Reserve [Line Items]        
Restructuring Costs 4 11 27 46
Inception to Date 96   96  
Estimated Remaining Costs 1   1  
Estimated Total Cost 97   97  
Employer Solutions | Severance and Related Benefits        
Restructuring Cost And Reserve [Line Items]        
Restructuring Costs 1 2 3 5
Inception to Date 10   10  
Estimated Remaining Costs 0   0  
Estimated Total Cost 10   10  
Employer Solutions | Other Restructuring Costs        
Restructuring Cost And Reserve [Line Items]        
Restructuring Costs 3 9 24 41
Inception to Date 86   86  
Estimated Remaining Costs 1   1  
Estimated Total Cost 87   87  
Corporate        
Restructuring Cost And Reserve [Line Items]        
Restructuring Costs 8 4 18 17
Inception to Date 37   37  
Estimated Remaining Costs 5   5  
Estimated Total Cost 42   42  
Corporate | Severance and Related Benefits        
Restructuring Cost And Reserve [Line Items]        
Restructuring Costs 7 3 15 15
Inception to Date 32   32  
Estimated Remaining Costs 0   0  
Estimated Total Cost 32   32  
Corporate | Other Restructuring Costs        
Restructuring Cost And Reserve [Line Items]        
Restructuring Costs 1 $ 1 3 $ 2
Inception to Date 5   5  
Estimated Remaining Costs 5   5  
Estimated Total Cost $ 10   $ 10