v3.26.1
Investments (Investments in Fixed Maturity and Equity Securities Available-for-Sale by Sector) (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Mar. 31, 2026
Dec. 31, 2025
Jun. 30, 2025
Mar. 31, 2025
Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]            
Available for Sale at Fair value - Amortized cost $ 116,308   $ 107,264      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 1,363   1,672      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 8,155   6,957      
Fixed maturity securities, available-for-sale $ 109,270 [1]   $ 101,769 [2]      
% of Total 100.00%   100.00%      
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 246 $ 232 $ 210 $ 132 $ 103 $ 98
Corporate Debt Securities [Member]            
Debt Securities, Available-for-sale [Line Items]            
Available for Sale at Fair value - Amortized cost 80,654   72,736      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 904   1,142      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 4,507   3,952      
Fixed maturity securities, available-for-sale $ 76,827 [1]   $ 69,737 [2]      
% of Total 70.30%   68.50%      
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 224 211 $ 189 112 88 82
Canadian and Canadian provincial governments            
Debt Securities, Available-for-sale [Line Items]            
Available for Sale at Fair value - Amortized cost 4,711   4,920      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 301   286      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 85   106      
Fixed maturity securities, available-for-sale $ 4,927 [1]   $ 5,100 [2]      
% of Total 4.50%   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 1,903   1,615      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 19   26      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 78   72      
Fixed maturity securities, available-for-sale $ 1,844 [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 7,214   7,478      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 48   69      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 180   157      
Fixed maturity securities, available-for-sale $ 7,060 [1]   $ 7,369 [2]      
% of Total 6.50%   7.20%      
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 22 21 $ 21 19 15 15
Commercial Mortgage Backed Securities [Member]            
Debt Securities, Available-for-sale [Line Items]            
Available for Sale at Fair value - Amortized cost 2,515   2,179      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 22   35      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 59   52      
Fixed maturity securities, available-for-sale $ 2,478 [1]   $ 2,162 [2]      
% of Total 2.30%   2.10%      
Debt Securities, Available-for-Sale, Allowance for Credit Loss $ 0 $ 0 $ 0 $ 1 $ 0 $ 1
US Treasury and Government [Member]            
Debt Securities, Available-for-sale [Line Items]            
Available for Sale at Fair value - Amortized cost 2,354   3,508      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 11   27      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 257   248      
Fixed maturity securities, available-for-sale $ 2,108 [1]   $ 3,287 [2]      
% of Total 1.90%   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 756   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 $ 674 [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 5,842   6,168      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax 56   83      
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax 410   379      
Fixed maturity securities, available-for-sale $ 5,488 [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 9,045   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 2,238   1,816      
Fixed maturity securities, available-for-sale $ 6,807   $ 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 1,314   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 257   96      
Fixed maturity securities, available-for-sale [1] $ 1,057   $ 1,312      
% of Total 1.00%   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 June 30, 2026, the fair value of such investments was $875 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