Segment Reporting (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) level3FinancialInstruments	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Segment Reporting, Revenue Reconciling Item [Line Items]
Number of Reportable Segments | level3FinancialInstruments			3
Revenues	$ 62	$ 86	$ 120	$ 206
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	(11)	6	(40)	9
Provision for income taxes	2	1	6	1
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(13)	5	(46)	8
Premiums Earned, Net	15	14	29	28
Net Investment Income	35	(21)	69	(16)
Amortization of Intangible Assets	7	13	13	28
Interest Expense	16	45	32
Total assets	8,132	10,061	8,132	10,061	$ 7,973
Premiums Written, Net	(45)	9	(27)	21
Derivative, Gain (Loss) on Derivative, Net	0	29	(3)	86
Net realized gains on extinguishment of debt	0	57	0	57
Insurance Commissions and Fees	10	6	25	15
Losses and loss adjustment expenses	7	(12)	25	12
Other Cost and Expense, Operating	36	29	72	58
Insurance Commissions	6	4	14	8
Depreciation	0	0	1	1
Benefits, Losses and Expenses	73	80	160	197
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest	0	0	(1)	0
Net income attributable to common shareholders	(13)	5	(47)	7
Realized Investment Gains (Losses)	(3)	7	(8)	17
Contractually Specified Servicing Fee, Late Fee, and Ancillary Fee Earned in Exchange for Servicing Financial Asset	2	1	4	1
Other income Items	3	(6)	4	18
Deferred Policy Acquisition Costs, Amortization Expense	1	0	3	0
Financial Guarantee
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	39	75	71	184
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	(8)	7	(40)	13
Premiums Earned, Net	8	11	14	24
Net Investment Income	32	(22)	63	(18)
Amortization of Intangible Assets	6	13	11	26
Interest Expense	16	45	32	89
Total assets	7,376	9,579	7,376	9,579
Derivative, Gain (Loss) on Derivative, Net	1	28	(3)	85
Net realized gains on extinguishment of debt	0	57	0	57
Losses and loss adjustment expenses	2	(14)	15	9
Other Cost and Expense, Operating	23	23	52	44
Depreciation	0	0	1	1
Benefits, Losses and Expenses	47	68	111	170
Realized Investment Gains (Losses)	(3)	7	(8)	17
Other income Items	2	(6)	4	18
Deferred Policy Acquisition Costs, Amortization Expense	0	0	0	0
Specialty Property & Casualty Program
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	11	4	20	5
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	0	(1)	(1)	(4)
Premiums Earned, Net	8	3	15	4
Net Investment Income	1	0	2	1
Total assets	395	229	395	229
Losses and loss adjustment expenses	6	2	10	3
Other Cost and Expense, Operating	4	3	8	6
Depreciation	0	0	0	0
Benefits, Losses and Expenses	11	5	21	9
Managing General Agency Underwriter
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	10	6	25	15
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	1	0	4	2
Amortization of Intangible Assets	1	1	2	1
Total assets	137	94	137	94
Insurance Commissions and Fees	10	6	25	15
Other Cost and Expense, Operating	2	2	5	3
Insurance Commissions	6	4	14	8
Depreciation	0	0	0	0
Benefits, Losses and Expenses	9	6	20	13
Corporate and Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	2	2	4	2
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	(4)	1	(3)	(3)
Net Investment Income	2	1	4	1
Total assets	225	159	225	159
Derivative, Gain (Loss) on Derivative, Net	0	1	0	1
Other Cost and Expense, Operating	6	1	7	4
Depreciation	0	0	0	0
Benefits, Losses and Expenses	6	1	8	4
Surplus Notes	0	61	0	61
Realized Investment Gains (Losses)	0	0	0	0
Other income Items	0	0	0	0
Property and Casualty, Commercial Insurance
Segment Reporting, Revenue Reconciling Item [Line Items]
Contractually Specified Servicing Fee, Late Fee, and Ancillary Fee Earned in Exchange for Servicing Financial Asset	2	1	4	1
Other income Items	0	0	0	0
Deferred Policy Acquisition Costs, Amortization Expense	1	0	3	0
Insurance Distribution
Segment Reporting, Revenue Reconciling Item [Line Items]
Other income Items	$ 0	$ 0	$ 0	$ 0