v3.26.1
Investment Information - Investment in operating affiliates (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Schedule of Equity Method Investments [Line Items]          
Investment in operating affiliates $ 1,323   $ 1,323   $ 1,313
Income (loss) from operating affiliates $ 46 $ 40 $ 82 $ 57  
Coface          
Schedule of Equity Method Investments [Line Items]          
Percentage ownership 29.90%   29.90%    
Investment in operating affiliates $ 664   $ 664   $ 707
Greysbridge Holdings Ltd          
Schedule of Equity Method Investments [Line Items]          
Percentage ownership 31.75%   31.75%   30.00%
Investment in operating affiliates $ 554   $ 554   $ 486
Issued Shares Excluding Treasury Stock | Coface          
Schedule of Equity Method Investments [Line Items]          
Percentage ownership 30.00%   30.00%