v3.26.1
Fair Value Measurements - Net realized and unrealized gains and losses included in income related to level 3 assets and liabilities (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets $ (34) $ 191
Net realized gains (losses), liabilities 430 (519)
Policyholder contract deposits    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities 649 222
Policyholder contract deposits | Policy Fees    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities 0 0
Policyholder contract deposits | Net Investment Income (Loss)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities 0 0
Policyholder contract deposits | Net Realized and Unrealized Gains (Losses)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities 649 222
Policyholder contract deposits | Change in the Fair Value of Market Risk Benefits, net    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities 0 0
Derivative liabilities, net    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities (233) (145)
Derivative liabilities, net | Policy Fees    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities 16 15
Derivative liabilities, net | Net Investment Income (Loss)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities 0 0
Derivative liabilities, net | Net Realized and Unrealized Gains (Losses)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities (249) (160)
Derivative liabilities, net | Change in the Fair Value of Market Risk Benefits, net    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities 0 0
Fortitude Re funds withheld payable    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities 14 (596)
Fortitude Re funds withheld payable | Policy Fees    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities 0 0
Fortitude Re funds withheld payable | Net Investment Income (Loss)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities 0 0
Fortitude Re funds withheld payable | Net Realized and Unrealized Gains (Losses)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities 14 (596)
Fortitude Re funds withheld payable | Change in the Fair Value of Market Risk Benefits, net    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities 0 0
Market risk benefit liabilities, net    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities (378) (577)
Market risk benefit liabilities, net | Policy Fees    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities 0 0
Market risk benefit liabilities, net | Net Investment Income (Loss)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities 0 0
Market risk benefit liabilities, net | Net Realized and Unrealized Gains (Losses)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities 0 (2)
Market risk benefit liabilities, net | Change in the Fair Value of Market Risk Benefits, net    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), liabilities (378) (575)
Bonds available-for-sale    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets 5 168
Bonds available-for-sale | Policy Fees    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets 0 0
Bonds available-for-sale | Net Investment Income (Loss)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets 29 146
Bonds available-for-sale | Net Realized and Unrealized Gains (Losses)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets (24) 22
Bonds available-for-sale | Change in the Fair Value of Market Risk Benefits, net    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets 0 0
Other bond securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets (14) 19
Other bond securities | Policy Fees    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets 0 0
Other bond securities | Net Investment Income (Loss)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets (14) 19
Other bond securities | Net Realized and Unrealized Gains (Losses)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets 0 0
Other bond securities | Change in the Fair Value of Market Risk Benefits, net    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets 0 0
Equity securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets (20) 0
Equity securities | Policy Fees    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets 0 0
Equity securities | Net Investment Income (Loss)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets (20) 0
Equity securities | Net Realized and Unrealized Gains (Losses)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets 0 0
Equity securities | Change in the Fair Value of Market Risk Benefits, net    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets 0 0
Other invested assets    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets (5) 4
Other invested assets | Policy Fees    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets 0 0
Other invested assets | Net Investment Income (Loss)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets (6) 4
Other invested assets | Net Realized and Unrealized Gains (Losses)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets 1 0
Other invested assets | Change in the Fair Value of Market Risk Benefits, net    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Net realized gains (losses), assets $ 0 $ 0