v3.24.0.1
Schedule I—Condensed Financial Information of Registrant (Parent Company Only) - Narrative (Details) - USD ($)
 12 Months Ended
Aug. 11, 2023
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]        
Debt   $ 8,092,000,000 $ 6,472,000,000  
AAM Series A Preferred Stock        
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]        
Preferred stock, dividend rate 6.75%      
Parent Company        
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]        
Debt   1,075,000,000 0  
Dividends from subsidiaries   $ 1,082,000,000 1,897,000,000 $ 500,000,000
Parent Company | AAM Series A Preferred Stock        
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]        
Preferred stock, dividend rate 6.75%      
Parent Company | Subsidiary | AAM        
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]        
Related party transaction, rate   0.33%    
Other receivables   $ 431,000,000 579,000,000  
Revolving Credit Facility | AHL Credit Facility | Parent Company | Subsidiary | AHL        
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]        
Line of credit facility, maximum borrowing capacity   500,000,000    
Revolving Credit Facility | AHL Credit Facility | Parent Company | Line of Credit | Subsidiary        
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]        
Line of credit facility, maximum borrowing capacity   500,000,000    
Debt   $ 109,000,000 $ 78,000,000