v3.26.1
INVESTMENTS - Held-to-Maturity Debt Securities (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Schedule of Held-to-maturity Securities [Line Items]        
Amortized Cost $ 15,756 $ 16,125    
Allowance for Credit Losses 4 5 $ 5 $ 5
Total fixed maturity securities, held-to-maturity, amortized cost 15,752 [1] 16,120    
Gross Unrealized Gains 14 87    
Gross Unrealized Losses 997 731    
Fair Value 14,769 15,476    
Yen-denominated        
Schedule of Held-to-maturity Securities [Line Items]        
Amortized Cost 15,756 16,125    
Allowance for Credit Losses 4 5    
Total fixed maturity securities, held-to-maturity, amortized cost 15,752 16,120    
Gross Unrealized Gains 14 87    
Gross Unrealized Losses 997 731    
Fair Value 14,769 15,476    
Japan government and agencies | Yen-denominated        
Schedule of Held-to-maturity Securities [Line Items]        
Amortized Cost 15,137 15,461    
Allowance for Credit Losses 1 2    
Total fixed maturity securities, held-to-maturity, amortized cost 15,136 15,459    
Gross Unrealized Gains 12 81    
Gross Unrealized Losses 971 713    
Fair Value 14,177 14,827    
Municipalities        
Schedule of Held-to-maturity Securities [Line Items]        
Fair Value 217 229    
Municipalities | Yen-denominated        
Schedule of Held-to-maturity Securities [Line Items]        
Amortized Cost 230 235    
Allowance for Credit Losses 0 0    
Total fixed maturity securities, held-to-maturity, amortized cost 230 235    
Gross Unrealized Gains 0 0    
Gross Unrealized Losses 13 6    
Fair Value 217 229    
Public utilities        
Schedule of Held-to-maturity Securities [Line Items]        
Fair Value 27 29    
Public utilities | Yen-denominated        
Schedule of Held-to-maturity Securities [Line Items]        
Amortized Cost 31 32    
Allowance for Credit Losses 0 0    
Total fixed maturity securities, held-to-maturity, amortized cost 31 32    
Gross Unrealized Gains 0 0    
Gross Unrealized Losses 4 3    
Fair Value 27 29    
Sovereign and supranational        
Schedule of Held-to-maturity Securities [Line Items]        
Fair Value 333 375    
Sovereign and supranational | Yen-denominated        
Schedule of Held-to-maturity Securities [Line Items]        
Amortized Cost 342 381    
Allowance for Credit Losses 3 3    
Total fixed maturity securities, held-to-maturity, amortized cost 339 378    
Gross Unrealized Gains 2 6    
Gross Unrealized Losses 8 9    
Fair Value 333 375    
Other corporate        
Schedule of Held-to-maturity Securities [Line Items]        
Fair Value 15 16    
Other corporate | Yen-denominated        
Schedule of Held-to-maturity Securities [Line Items]        
Amortized Cost 16 16    
Allowance for Credit Losses 0 0    
Total fixed maturity securities, held-to-maturity, amortized cost 16 16    
Gross Unrealized Gains 0 0    
Gross Unrealized Losses 1 0    
Fair Value $ 15 $ 16    
[1] Net of allowance for credit losses