v3.26.1
Borrowings - Schedule of Components of Long-Term Debt (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Debt Instrument [Line Items]    
Total long-term debt $ 10,877 $ 9,917
Parent Company    
Debt Instrument [Line Items]    
Total long-term debt 5,839 5,106
Parent Company | Senior Notes Due 2027-2037 | Senior Notes    
Debt Instrument [Line Items]    
Senior notes $ 5,394 4,659
Parent Company | Senior Notes Due 2027-2037 | Senior Notes | Minimum    
Debt Instrument [Line Items]    
Stated rate 2.25%  
Parent Company | Senior Notes Due 2027-2037 | Senior Notes | Maximum    
Debt Instrument [Line Items]    
Stated rate 6.40%  
Parent Company | Junior Subordinated Debentures Due 2028-2037 | Subordinated notes    
Debt Instrument [Line Items]    
Junior subordinated debentures $ 445 447
Parent Company | Junior Subordinated Debentures Due 2028-2037 | Subordinated notes | Minimum    
Debt Instrument [Line Items]    
Stated rate 4.66%  
Parent Company | Junior Subordinated Debentures Due 2028-2037 | Subordinated notes | Maximum    
Debt Instrument [Line Items]    
Stated rate 7.75%  
Subsidiaries    
Debt Instrument [Line Items]    
Total long-term debt $ 5,038 4,811
Subsidiaries | Senior Notes Due 2027-2039 | Senior Notes    
Debt Instrument [Line Items]    
Senior notes $ 2,222 2,229
Subsidiaries | Senior Notes Due 2027-2039 | Senior Notes | Minimum    
Debt Instrument [Line Items]    
Stated rate 3.75%  
Subsidiaries | Senior Notes Due 2027-2039 | Senior Notes | Maximum    
Debt Instrument [Line Items]    
Stated rate 5.85%  
Subsidiaries | Subordinated Notes Due 2026- 2032 | Subordinated notes    
Debt Instrument [Line Items]    
Junior subordinated debentures $ 1,930 1,932
Subsidiaries | Subordinated Notes Due 2026- 2032 | Subordinated notes | Minimum    
Debt Instrument [Line Items]    
Stated rate 3.40%  
Subsidiaries | Subordinated Notes Due 2026- 2032 | Subordinated notes | Maximum    
Debt Instrument [Line Items]    
Stated rate 6.95%  
Subsidiaries | Federal Home Loan Bank advances    
Debt Instrument [Line Items]    
Federal Home Loan Bank advances $ 808 560
Subsidiaries | Federal Home Loan Bank advances | Minimum    
Debt Instrument [Line Items]    
Stated rate 1.39%  
Subsidiaries | Federal Home Loan Bank advances | Maximum    
Debt Instrument [Line Items]    
Stated rate 7.36%  
Subsidiaries | Secured borrowing    
Debt Instrument [Line Items]    
Other long-term debt $ 78 $ 90