v3.26.1
Investments - Equity Securities At Fair Value (Detail) - USD ($)
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Debt and Equity Securities, FV-NI [Line Items]      
Equity securities, at fair value $ 14,428,000,000   $ 13,866,000,000
Equity securities      
Debt and Equity Securities, FV-NI [Line Items]      
Equity method investment 4,030,000,000.00   $ 4,230,000,000
Fair value option      
Debt and Equity Securities, FV-NI [Line Items]      
Gains/(losses) recognized on equity securities $ 0 $ 0  
Corporate Equity Securities      
Debt and Equity Securities, FV-NI [Line Items]      
Percentage of investment in equity securities 79.00%   78.00%
Real estate      
Debt and Equity Securities, FV-NI [Line Items]      
Percentage of investment in equity securities 21.00%   22.00%
Corporate and Real estate      
Debt and Equity Securities, FV-NI [Line Items]      
Percentage of investment in equity securities 100.00%   100.00%
Public and Private equity      
Debt and Equity Securities, FV-NI [Line Items]      
Percentage of investment in equity securities 100.00%   100.00%
Public equity      
Debt and Equity Securities, FV-NI [Line Items]      
Percentage of investment in equity securities 3.00%   4.00%
Private equity      
Debt and Equity Securities, FV-NI [Line Items]      
Percentage of investment in equity securities 97.00%   96.00%