Income Taxes - Significant Portions of Deferred Tax Liabilities and Deferred Tax Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Schedule of Deferred Income Tax Assets and Liabilities [Line Items]
Deferred Tax Assets, Net of Valuation Allowance	$ 58	$ 70
Deferred tax assets:
Net operating loss and capital carryforward	714	725
Deferred Tax Asset, Interest Carryforward	58	66
Deferred Tax Assets, Investments	0	6
Loss reserves	42	38
Deferred Tax Assets, Operating Loss Carryforwards, State and Local	8	8
Deferred Tax Assets, Debentures	22	15
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Compensation	5	6
Other	4	4
Sub total deferred tax assets	853	867
Valuation allowance	795	796
Insurance intangible	51	56
Variable interest entities	0	4
Unearned premiums and credit fees	23	24
Other	3	1
Deferred Tax Liabilities, Gross	77	85
Deferred Tax Liabilities, Net	$ 19	$ 15