v3.26.1
Investments - Equity Securities At Fair Value (Detail) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Debt and Equity Securities, FV-NI [Line Items]    
Equity securities, at fair value $ 14,226 $ 13,866
Equity securities    
Debt and Equity Securities, FV-NI [Line Items]    
Equity method investment $ 3,910 $ 4,230
Corporate Equity Securities    
Debt and Equity Securities, FV-NI [Line Items]    
Percentage of investment in equity securities 80.00% 78.00%
Real estate    
Debt and Equity Securities, FV-NI [Line Items]    
Percentage of investment in equity securities 20.00% 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%