v3.25.4
Investments - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Debt and Equity Securities, FV-NI [Line Items]      
Weighted Average Yield 3.81% 3.29%  
Gross unrealized gain included in accumulated other comprehensive gain/(loss) $ 626,000,000 $ 0  
Net unrealized losses included in other comprehensive income/(loss before tax 1,450,000,000 541,000,000  
Net unrealized losses included in other comprehensive income/(loss) after tax 1,075,000,000 401,000,000 $ 1,245,000,000
Debt securities, available-for-sale, realized gain $ 0 $ 0  
Debt securities, available-for-sale, realized loss     $ (135,000,000)