Fair Value of Assets and Liabilities - Schedule of Financial Instruments Not Carried at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financial assets
Mortgage loans	$ 784	$ 822
Financial liabilities
Debt	8,085	7,942
Liability for collateral	2,041	1,891	$ 2,011	$ 1,444
Liabilities held for sale	2,113	0
Significant unobservable inputs (Level 3) | Amortized cost, net
Financial assets
Mortgage loans	784	822
Bank loans	201	224
Financial liabilities
Contractholder funds on investment contracts	0	46
Liabilities held for sale	40	0
Significant unobservable inputs (Level 3) | Fair value
Financial assets
Mortgage loans	746	769
Bank loans	207	238
Financial liabilities
Contractholder funds on investment contracts	0	46
Liabilities held for sale	40	0
Significant other observable inputs (Level 2) | Amortized cost, net
Financial liabilities
Debt	8,085	7,942
Liability for collateral	2,041	1,891
Significant other observable inputs (Level 2) | Fair value
Financial liabilities
Debt	7,740	7,655
Liability for collateral	$ 2,041	$ 1,891