v3.26.1
Investments (Investments in Fixed Maturity and Equity Securities Available-for-Sale by Sector) (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]        
Available for Sale at Fair value - Amortized cost $ 114,976 $ 107,264    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 1,067 1,672    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 8,483 6,957    
Fixed maturity securities, available-for-sale $ 107,328 [1] $ 101,769 [2]    
% of Total 100.00% 100.00%    
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 232 $ 210 $ 103 $ 98
Corporate Debt Securities [Member]        
Debt Securities, Available-for-sale [Line Items]        
Available for Sale at Fair value - Amortized cost 77,736 72,736    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 676 1,142    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 4,973 3,952    
Fixed maturity securities, available-for-sale $ 73,228 [1] $ 69,737 [2]    
% of Total 68.20% 68.50%    
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 211 $ 189 88 82
Canadian and Canadian provincial governments        
Debt Securities, Available-for-sale [Line Items]        
Available for Sale at Fair value - Amortized cost 4,897 4,920    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 251 286    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 133 106    
Fixed maturity securities, available-for-sale $ 5,015 [1] $ 5,100 [2]    
% of Total 4.70% 5.10%    
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 0 $ 0    
Residential mortgage-backed securities        
Debt Securities, Available-for-sale [Line Items]        
Available for Sale at Fair value - Amortized cost 1,599 1,615    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 18 26    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 74 72    
Fixed maturity securities, available-for-sale $ 1,543 [1] $ 1,569 [2]    
% of Total 1.40% 1.50%    
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 0 $ 0    
Asset-backed Securities [Member]        
Debt Securities, Available-for-sale [Line Items]        
Available for Sale at Fair value - Amortized cost 7,436 7,478    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 44 69    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 178 157    
Fixed maturity securities, available-for-sale $ 7,281 [1] $ 7,369 [2]    
% of Total 6.80% 7.20%    
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 21 $ 21 15 15
Commercial Mortgage Backed Securities [Member]        
Debt Securities, Available-for-sale [Line Items]        
Available for Sale at Fair value - Amortized cost 2,367 2,179    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 25 35    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 57 52    
Fixed maturity securities, available-for-sale $ 2,335 [1] $ 2,162 [2]    
% of Total 2.20% 2.10%    
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 0 $ 0 $ 0 $ 1
US Treasury and Government [Member]        
Debt Securities, Available-for-sale [Line Items]        
Available for Sale at Fair value - Amortized cost 2,805 3,508    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 14 27    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 257 248    
Fixed maturity securities, available-for-sale $ 2,562 [1] $ 3,287 [2]    
% of Total 2.40% 3.30%    
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 0 $ 0    
US States and Political Subdivisions Debt Securities [Member]        
Debt Securities, Available-for-sale [Line Items]        
Available for Sale at Fair value - Amortized cost 737 737    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 2 2    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 84 79    
Fixed maturity securities, available-for-sale $ 655 [1] $ 660 [2]    
% of Total 0.60% 0.60%    
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 0 $ 0    
Debt Security, Government, Non-US [Member]        
Debt Securities, Available-for-sale [Line Items]        
Available for Sale at Fair value - Amortized cost 6,180 6,168    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 37 83    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 488 379    
Fixed maturity securities, available-for-sale $ 5,729 [1] $ 5,872 [2]    
% of Total 5.30% 5.80%    
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 0 $ 0    
JAPAN        
Debt Securities, Available-for-sale [Line Items]        
Available for Sale at Fair value - Amortized cost 9,873 6,516    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 0 1    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 2,056 1,816    
Fixed maturity securities, available-for-sale $ 7,817 $ 4,701    
% of Total 7.30% 4.60%    
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 0 $ 0    
KOREA, REPUBLIC OF        
Debt Securities, Available-for-sale [Line Items]        
Available for Sale at Fair value - Amortized cost 1,346 1,407    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 0 1    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 183 96    
Fixed maturity securities, available-for-sale $ 1,163 [1] $ 1,312 [2]    
% of Total 1.10% 1.30%    
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 0 $ 0    
[1] Excludes limited partnerships that are measured at estimated fair value using the NAV per share (or its equivalent) as a practical expedient. As of March 31, 2026, the fair value of such investments was $935 million.
[2] Excludes limited partnerships that are measured at estimated fair value using the NAV per share (or its equivalent) as a practical expedient. As of December 31, 2025, the fair value of such investments was $925 million