Income Taxes - Significant Portions of Deferred Tax Liabilities and Deferred Tax Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Schedule of Deferred Income Tax Assets and Liabilities [Line Items]
Deferred Tax Assets, Net of Valuation Allowance	$ 70	$ 106
Deferred tax assets:
Net operating loss and capital carryforward	725	736
Deferred Tax Asset, Interest Carryforward	66	50
Deferred Tax Assets, Investments	6
Loss reserves	38	180
Deferred Tax Assets, Operating Loss Carryforwards, State and Local	8	7
Deferred Tax Assets, Debentures	15	7
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Compensation	6	8
Other	4	4
Sub total deferred tax assets	867	993
Valuation allowance	796	886
Insurance intangible	56	67
Variable interest entities	4	15
Investments		14
Unearned premiums and credit fees	24	32
Other	1	6
Deferred Tax Liabilities, Gross	85	134
Deferred Tax Liabilities, Net	$ 15	$ 28