v3.26.3
FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets by Pricing Source, Securities Carried at Amortized Cost (Details) - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value $ 14,329 $ 15,476
Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 13,652 14,696
Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 677 780
Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 0 0
Government and agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 13,772 14,827
Government and agencies | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 13,652 14,696
Government and agencies | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 120 131
Government and agencies | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 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, held-to-maturity, fair value 13,772 14,827
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, held-to-maturity, fair value 13,652 14,696
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, held-to-maturity, fair value 120 131
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, held-to-maturity, fair value 0 0
Municipalities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 205 229
Municipalities | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 0 0
Municipalities | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 205 229
Municipalities | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 0 0
Municipalities | Third-party pricing vendor    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 205 229
Municipalities | Third-party pricing vendor | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 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, held-to-maturity, fair value 205 229
Municipalities | Third-party pricing vendor | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 0 0
Public utilities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 26 29
Public utilities | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 0 0
Public utilities | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 26 29
Public utilities | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 0 0
Public utilities | Third-party pricing vendor    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 26 29
Public utilities | Third-party pricing vendor | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 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, held-to-maturity, fair value 26 29
Public utilities | Third-party pricing vendor | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 0 0
Sovereign and supranational    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 312 375
Sovereign and supranational | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 0 0
Sovereign and supranational | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 312 375
Sovereign and supranational | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 0 0
Sovereign and supranational | Third-party pricing vendor    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 139 188
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, held-to-maturity, fair value 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, held-to-maturity, fair value 139 188
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, held-to-maturity, fair value 0 0
Sovereign and supranational | Internal    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 173 187
Sovereign and supranational | Internal | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 0 0
Sovereign and supranational | Internal | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 173 187
Sovereign and supranational | Internal | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 0 0
Other corporate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 14 16
Other corporate | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 0 0
Other corporate | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 14 16
Other corporate | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 0 0
Other corporate | Third-party pricing vendor    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 14 16
Other corporate | Third-party pricing vendor | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value 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, held-to-maturity, fair value 14 16
Other corporate | Third-party pricing vendor | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturity securities, held-to-maturity, fair value $ 0 $ 0