v3.26.1
Fair Value - Summary of Changes in Fair Value Associated with Level 3 Assets (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning balance $ 105 $ 105
Calls/ Maturities/ Paydowns/Other 1 6
Purchases 0 8
Sales (5) 0
Net Realized (Gain)/Loss on Sales (7) 0
Change in Valuation 1 (14)
Net Transfers In (Out) 0 0
Fair value, ending balance 95 105
Corporate and other debt    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning balance 4 5
Calls/ Maturities/ Paydowns/Other 0 0
Purchases 0 0
Sales 0 0
Net Realized (Gain)/Loss on Sales 0 0
Change in Valuation 0 0
Net Transfers In (Out) 0 0
Fair value, ending balance 4 5
Nonredeemable preferred stocks    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning balance 60 52
Calls/ Maturities/ Paydowns/Other 0 0
Purchases 0 8
Sales (5) 0
Net Realized (Gain)/Loss on Sales (7) 0
Change in Valuation 1 0
Net Transfers In (Out) 0 0
Fair value, ending balance 49 60
Common equities | Common Stocks, excluding Other Risk    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning balance 5 23
Calls/ Maturities/ Paydowns/Other 0 0
Purchases 0 0
Sales 0 0
Net Realized (Gain)/Loss on Sales 0 0
Change in Valuation 0 (14)
Net Transfers In (Out) 0 0
Fair value, ending balance 5 9
Common equities | Other risk investments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Fair value, beginning balance 36 25
Calls/ Maturities/ Paydowns/Other 1 6
Purchases 0 0
Sales 0 0
Net Realized (Gain)/Loss on Sales 0 0
Change in Valuation 0 0
Net Transfers In (Out) 0 0
Fair value, ending balance $ 37 $ 31