v3.26.3
Investments (Investments in Fixed Maturity and Equity Securities Available-for-Sale by Sector) (Details) - USD ($)
$ in Millions
Sep. 30, 2026
Jun. 30, 2026
Dec. 31, 2025
Sep. 30, 2025
Jun. 30, 2025
Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]            
Available for Sale at Fair value - Amortized cost $ 121,126   $ 107,264      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 464   1,672      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 13,617   6,957      
Fixed maturity securities, available-for-sale $ 107,757 [1]   $ 101,769 [2]      
% of Total 100.00%   100.00%      
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 216 $ 246 $ 210 $ 161 $ 132 $ 98
Corporate Debt Securities [Member]            
Debt Securities, Available-for-sale [Line Items]            
Available for Sale at Fair value - Amortized cost 83,446   72,736      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 240   1,142      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 8,764   3,952      
Fixed maturity securities, available-for-sale $ 74,727 [1]   $ 69,737 [2]      
% of Total 69.40%   68.50%      
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 195 224 $ 189 141 112 82
Canadian and Canadian provincial governments            
Debt Securities, Available-for-sale [Line Items]            
Available for Sale at Fair value - Amortized cost 4,794   4,920      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 155   286      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 281   106      
Fixed maturity securities, available-for-sale $ 4,668 [1]   $ 5,100 [2]      
% of Total 4.30%   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 2,030   1,615      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 6   26      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 154   72      
Fixed maturity securities, available-for-sale $ 1,882 [1]   $ 1,569 [2]      
% of Total 1.70%   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 8,193   7,478      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 37   69      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 294   157      
Fixed maturity securities, available-for-sale $ 7,915 [1]   $ 7,369 [2]      
% of Total 7.40%   7.20%      
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 21 22 $ 21 19 19 15
Commercial Mortgage Backed Securities [Member]            
Debt Securities, Available-for-sale [Line Items]            
Available for Sale at Fair value - Amortized cost 2,609   2,179      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 9   35      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 100   52      
Fixed maturity securities, available-for-sale $ 2,518 [1]   $ 2,162 [2]      
% of Total 2.30%   2.10%      
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 0 $ 0 $ 0 $ 1 $ 1 $ 1
US Treasury and Government [Member]            
Debt Securities, Available-for-sale [Line Items]            
Available for Sale at Fair value - Amortized cost 2,545   3,508      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 1   27      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 342   248      
Fixed maturity securities, available-for-sale $ 2,204 [1]   $ 3,287 [2]      
% of Total 2.00%   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 753   737      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 0   2      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 128   79      
Fixed maturity securities, available-for-sale $ 625 [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 6,005   6,168      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 16   83      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 642   379      
Fixed maturity securities, available-for-sale $ 5,379 [1]   $ 5,872 [2]      
% of Total 5.00%   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 9,230   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 2,588   1,816      
Fixed maturity securities, available-for-sale $ 6,642   $ 4,701      
% of Total 6.20%   4.60%      
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 0   $ 0      
Korean Government Debt Securities            
Debt Securities, Available-for-sale [Line Items]            
Available for Sale at Fair value - Amortized cost 1,521   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 324   96      
Fixed maturity securities, available-for-sale [1] $ 1,197   $ 1,312      
% 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 September 30, 2026, the fair value of such investments was $926 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