Reserves for Insurance Losses and Loss Adjustment Expenses - Schedule of Short-Duration Insurance Contracts, Reconciliation of Claims Development to Liability (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Short-Duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Reserves for insurance losses and loss adjustment expenses, net of reinsurance	$ 126	$ 71	$ 44
Total reinsurance recoverable on unpaid claims	60	66	72	$ 81
Unallocated loss adjustment expenses	3	3	3
Total gross reserves for insurance losses and loss adjustment expenses	$ 189	$ 140	$ 119	$ 122