Summary of Significant Accounting Policies - Schedule of Allowance for Credit Loss (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Fixed income securities	$ 36	$ 13	$ 6
Investments	69	77
Premium installment receivables	138	132	107
Reinsurance recoverables	65	65
Other assets	18	19
Assets	290	293
Commitments to fund mortgage loans and bank loans	1	0
Liabilities	1	0
Total	291	293
Fixed income securities
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Fixed income securities	36	13	6	$ 2
Mortgage loans
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance credit losses	11	7	$ 6	$ 67
Bank loans
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance credit losses	$ 22	$ 57