v3.26.1
Investments (Gross Realized Gains and Losses From Sales Of Available-For-Sale Securities) (Detail) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Investments [Abstract]    
Proceeds from sales $ 0 $ 62
Available For Sale Securities Realized Gain Loss [Abstract]    
Gross realized gains 0 1
Gross realized losses $ 0 $ (6)