v3.26.1
FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets by Pricing Source, Securities Carried at Fair Value (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale $ 63,228 $ 64,121
Equity securities 851 887
Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 12,993 13,921
Equity securities 692 727
Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 46,597 46,843
Equity securities 0 0
Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 3,638 3,357
Equity securities 159 160
Third-party pricing vendor    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 692 727
Third-party pricing vendor | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 692 727
Third-party pricing vendor | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 0 0
Third-party pricing vendor | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 0 0
Internal    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 22 24
Internal | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 0 0
Internal | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 0 0
Internal | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 22 24
Broker/other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 137 136
Broker/other | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 0 0
Broker/other | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 0 0
Broker/other | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 137 136
Government and agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 13,572 14,607
Government and agencies | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 12,993 13,921
Government and agencies | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 579 686
Government and agencies | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Government and agencies | Third-party pricing vendor    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 13,378 14,304
Government and agencies | Third-party pricing vendor | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 12,993 13,921
Government and agencies | Third-party pricing vendor | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 385 383
Government and agencies | Third-party pricing vendor | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Government and agencies | Internal    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 194 303
Government and agencies | Internal | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Government and agencies | Internal | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 194 303
Government and agencies | Internal | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Municipalities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 1,878 1,930
Municipalities | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Municipalities | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 1,878 1,930
Municipalities | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Municipalities | Third-party pricing vendor    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 1,664 1,706
Municipalities | Third-party pricing vendor | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Municipalities | Third-party pricing vendor | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 1,664 1,706
Municipalities | Third-party pricing vendor | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Municipalities | Internal    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 214 224
Municipalities | Internal | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Municipalities | Internal | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 214 224
Municipalities | Internal | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Mortgage- and asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 5,037 4,366
Mortgage- and asset-backed securities | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Mortgage- and asset-backed securities | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 2,382 2,072
Mortgage- and asset-backed securities | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 2,655 2,294
Mortgage- and asset-backed securities | Third-party pricing vendor    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 1,993 1,824
Mortgage- and asset-backed securities | Third-party pricing vendor | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Mortgage- and asset-backed securities | Third-party pricing vendor | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 1,993 1,824
Mortgage- and asset-backed securities | Third-party pricing vendor | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Mortgage- and asset-backed securities | Internal    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 389 248
Mortgage- and asset-backed securities | Internal | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Mortgage- and asset-backed securities | Internal | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 389 248
Mortgage- and asset-backed securities | Internal | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Mortgage- and asset-backed securities | Broker/other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 2,655 2,294
Mortgage- and asset-backed securities | Broker/other | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Mortgage- and asset-backed securities | Broker/other | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Mortgage- and asset-backed securities | Broker/other | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 2,655 2,294
Public utilities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 6,954 7,174
Public utilities | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Public utilities | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 6,129 6,298
Public utilities | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 825 876
Public utilities | Third-party pricing vendor    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 3,630 3,660
Public utilities | Third-party pricing vendor | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Public utilities | Third-party pricing vendor | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 3,630 3,660
Public utilities | Third-party pricing vendor | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Public utilities | Internal    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 2,499 2,638
Public utilities | Internal | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Public utilities | Internal | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 2,499 2,638
Public utilities | Internal | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Public utilities | Broker/other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 825 876
Public utilities | Broker/other | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Public utilities | Broker/other | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Public utilities | Broker/other | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 825 876
Sovereign and supranational    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 385 402
Sovereign and supranational | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Sovereign and supranational | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 366 383
Sovereign and supranational | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 19 19
Sovereign and supranational | Third-party pricing vendor    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 76 79
Sovereign and supranational | Third-party pricing vendor | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Sovereign and supranational | Third-party pricing vendor | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 76 79
Sovereign and supranational | Third-party pricing vendor | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Sovereign and supranational | Internal    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 290 304
Sovereign and supranational | Internal | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Sovereign and supranational | Internal | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 290 304
Sovereign and supranational | Internal | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Sovereign and supranational | Broker/other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 19 19
Sovereign and supranational | Broker/other | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Sovereign and supranational | Broker/other | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Sovereign and supranational | Broker/other | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 19 19
Banks/financial institutions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 9,194 9,244
Banks/financial institutions | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Banks/financial institutions | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 9,190 9,235
Banks/financial institutions | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 4 9
Banks/financial institutions | Third-party pricing vendor    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 5,572 5,605
Banks/financial institutions | Third-party pricing vendor | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Banks/financial institutions | Third-party pricing vendor | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 5,572 5,605
Banks/financial institutions | Third-party pricing vendor | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Banks/financial institutions | Internal    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 3,618 3,635
Banks/financial institutions | Internal | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Banks/financial institutions | Internal | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 3,618 3,630
Banks/financial institutions | Internal | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 5
Banks/financial institutions | Broker/other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 4 4
Banks/financial institutions | Broker/other | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Banks/financial institutions | Broker/other | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Banks/financial institutions | Broker/other | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 4 4
Other corporate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 26,208 26,398
Other corporate | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Other corporate | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 26,073 26,239
Other corporate | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 135 159
Other corporate | Third-party pricing vendor    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 21,373 21,294
Other corporate | Third-party pricing vendor | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Other corporate | Third-party pricing vendor | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 21,373 21,294
Other corporate | Third-party pricing vendor | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Other corporate | Internal    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 4,700 4,965
Other corporate | Internal | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Other corporate | Internal | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 4,700 4,945
Other corporate | Internal | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 20
Other corporate | Broker/other    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 135 139
Other corporate | Broker/other | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Other corporate | Broker/other | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale 0 0
Other corporate | Broker/other | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, available-for-sale $ 135 $ 139