Fair Value of Assets and Liabilities - Schedule of Financial Instruments Not Carried at Fair Value (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023	Dec. 31, 2022
Financial assets
Mortgage loans	$ 815	$ 822
Financial liabilities
Debt	8,082	7,942
Liability for collateral	2,001	1,891	$ 1,791	$ 2,011
Significant unobservable inputs (Level 3) | Amortized cost, net
Financial assets
Mortgage loans	815	822
Bank loans	149	224
Financial liabilities
Contractholder funds on investment contracts	42	46
Significant unobservable inputs (Level 3) | Fair value
Financial assets
Mortgage loans	762	769
Bank loans	161	238
Financial liabilities
Contractholder funds on investment contracts	42	46
Significant other observable inputs (Level 2) | Amortized cost, net
Financial liabilities
Debt	8,082	7,942
Liability for collateral	2,001	1,891
Significant other observable inputs (Level 2) | Fair value
Financial liabilities
Debt	7,690	7,655
Liability for collateral	$ 2,001	$ 1,891