Reserves for Insurance Losses and Loss Adjustment Expenses - Schedule of Insurance Losses and Loss Adjustment Expenses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Total gross reserves for insurance losses and loss adjustment expenses, beginning balance	$ 140	$ 119	$ 122
Less: Reinsurance recoverable	66	72	81
Net reserves for insurance losses and loss adjustment expenses	129	74	47	$ 41
Current year	521	414	282
Prior years	23	8	(2)
Total net insurance losses and loss adjustment expenses incurred	544	422	280
Current year	(420)	(354)	(246)
Prior years	(69)	(41)	(28)
Total net insurance losses and loss adjustment expenses paid or payable	(489)	(395)	(274)
Plus: Reinsurance recoverable	60	66	72
Total gross reserves for insurance losses and loss adjustment expenses, ending balance	$ 189	$ 140	$ 119