Summary of Significant Accounting Policies - Schedule of Allowance for Credit Loss (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Fixed income securities	$ 17	$ 36	$ 13
Investments	39	69
Premium installment receivables	187	138	132
Reinsurance recoverables	63	65
Other assets	14	18
Assets	303	290
Commitments to fund mortgage loans and bank loans	0	1
Liabilities	0	1
Total	303	291
Fixed income securities
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Fixed income securities	17	36	13	$ 6
Mortgage loans
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance credit losses	12	11	$ 7	$ 6
Bank loans
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance credit losses	$ 10	$ 22