Summary of Significant Accounting Policies - Schedule of Allowance for Credit Loss (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Fixed income securities	$ 10	$ 17	$ 36
Investments	37	39
Premium installment receivables	189	187	138
Reinsurance recoverables	54	63
Other assets	15	14
Assets	295	303
Commitments to fund line of credit, commercial mortgage loans and bank loans	15	0
Liabilities	15	0
Total	310	303
Fixed income securities
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Fixed income securities	10	17	36	$ 13
Mortgage loans
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance credit losses	10	12	$ 11	$ 7
Bank loans
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance credit losses	$ 17	$ 10