Short term investments
Other Short-Term Investments
Stock Appreciation Rights (SARs)
Stock Appreciation Rights (SARs) [Member]
Future premiums expected to be collected, June 30. 2021
Financial Guarantee Insurance Contract, Premium Receivable, to be Collected, Second Quarter
Proceeds from Sale of Debt Securities, Available-for-Sale
Proceeds from Sale of Debt Securities, Available-for-Sale
Parsed Investment Type [Axis]
Parsed Investment Type [Axis]
Parsed Investment Type
Estimated Future Premium Payments Maximum Discounted Rate
Estimated Future Premium Payments Maximum Discounted Rate
Estimated Future Premium Payments Maximum Discounted Rate
Redeemable Noncontrolling Interest, Equity, Redemption Value
Redeemable Noncontrolling Interest, Equity, Redemption Value
Award Type [Domain]
Award Type [Domain]
Business Combination, Number of Days to Calculate VWAP
Business Combination, Number of Days to Calculate VWAP
Business Combination, Number of Days to Calculate VWAP
Fair Value as of Grant Date
Award Grant Date Fair Value
Present Value of Expected Net Cash Flows- Claims and Loss Expenses [Member]
Present Value of Expected Net Cash Flows- Claims and Loss Expenses [Member]
Claims and Loss Expenses [Member]
Debt and Equity Securities, FV-NI [Line Items]
Debt and Equity Securities, FV-NI [Line Items]
Other investments
Other Investments Income
Other Investments Income
Other Investments Income
Past Due Premiums Receivable
Past Due Premiums Receivable
Past Due Premiums Receivable
Class of Financing Receivable [Domain]
Class of Financing Receivable [Domain]
Insider Trading Policies and Procedures [Line Items]
Rule 10b5-1 Arrangement Terminated
Rule 10b5-1 Arrangement Terminated [Flag]
Debt Securities, Trading, Realized Gain (Loss)
Debt Securities, Trading, Realized Gain (Loss)
Restatement does not require Recovery
Restatement Does Not Require Recovery [Text Block]
Background and Business Description
Business Description and Basis of Presentation [Text Block]
Determination Date [Axis]
Determination Date [Axis]
Determination Date [Axis]
Future expected premiums to be earned, net of reinsurance, December 31, 2050
Financial Guarantee Insurance Contract, Premium Revenue to be Recognized, after Year 25 Through 30
Fair Value Inputs Maturity
Fair Value Inputs Maturity
Fair value inputs maturity.
Variable Interest Entity [Line Items]
Variable Interest Entities [Line Items]
Variable Interest Entity [Line Items]
Business Combination, Percentage Ownership Retained by Rollover Shareholders
Business Combination, Percentage Ownership Retained by Rollover Shareholders
Business Combination, Percentage Ownership Retained by Rollover Shareholders
Reporting Unit [Domain]
Reporting Unit [Domain]
Premium Receivable, Allowance for Credit Loss [Table Text Block]
Premium Receivable, Allowance for Credit Loss [Table Text Block]
Amortized Cost And Fair Value Debt Securities [Abstract]
Amortized Cost And Fair Value Debt Securities [Abstract]
Amortized Cost and Fair Value Debt Securities [Abstract]
Deferred Federal Income Tax Expense (Benefit)
Deferred Federal Income Tax Expense (Benefit)
Derivative and other assets
Derivative and other assets
Derivative and other assets
Preferred stock, par value $0.01 per share; 20,000,000 shares authorized; issued and outstanding shares—none
Preferred Stock, Value, Issued
Subsequent Event Type [Domain]
Subsequent Event Type [Domain]
Debt Security Category [Axis]
Debt Security Category [Axis]
Business Combination, Value of Shares Issued for Beat Acquisition
Business Combination, Value of Shares Issued for Beat Acquisition
Business Combination, Value of Shares Issued for Beat Acquisition
Earnings Per Share, Diluted
Earnings Per Share, Diluted
Schedule of Investments [Table]
Schedule of Investments [Table]
Treasury stock, shares at cost: 0 and 8,202
Treasury Stock, Value
Reinsurance Recoverable, Allowance for Credit Loss
Reinsurance Recoverable, Allowance for Credit Loss
Summary of Ceded Par and Net Unsecured Reinsurance Recoverable [Table]
Summary Of Ceded Par And Net Unsecured Reinsurance Recoverable [Table]
Summary of Ceded Par and Net Unsecured Reinsurance Recoverable [Table]
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Elements [Abstract]
Mortgage Backed And Home Equity [Member]
Mortgage Backed And Home Equity [Member]
Mortgage Backed and Home Equity [Member]
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, after Tax
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, after Tax
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, after Tax
Fair Value Inputs Yield Rate
Fair Value Inputs Yield Rate
Fair Value Inputs Yield Rate
Redeemable Noncontrolling Interest, Equity, Carrying Amount
Redeemable Noncontrolling Interest, Equity, Carrying Amount
Trading Symbol
Trading Symbol
Letters of Credit Outstanding, Amount
Letters of Credit Outstanding, Amount
Accelerated premium revenue for retired obligations
Financial Guarantee Insurance Contracts, Accelerated Premium Revenue, Amount
Financial Guarantee Insurance Contracts, Accelerated Premium Revenue, Amount
Guarantor Obligations, Nature [Domain]
Guarantor Obligations, Nature [Domain]
Structured Finance [Member]
Structured Finance [Member]
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Abstract]
Intangible Assets, Gross (Excluding Goodwill)
Intangible Assets, Gross (Excluding Goodwill)
All Currencies [Domain]
All Currencies [Domain]
Schedule of Equity Method Investments [Table]
Schedule of Equity Method Investments [Table]
Proceeds from sales of other invested assets
Proceeds from Sale and Maturity of Other Investments
Investments
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]
Loans Unpaid Principal Balance
Loans Unpaid Principal Balance
This represents the amount of principal outstanding on loans receivable that are presented on the balance sheet at fair value, whether such presentation is as a separate caption or parenthetical disclosure.
Contract with Customer, Liability
Contract with Customer, Liability
Schedule of Loss And Loss Expense Reserves And Subrogation Recoverable Table [Table Text Block]
Schedule of Loss And Loss Expense Reserves And Subrogation Recoverable Table [Table Text Block]
Tabular disclosure that provides regarding the balance sheet line items for the liability "Loss and Loss Expense Reserves" and the asset "Subrogation Recoverable". Includes the various components of Unpaid Claims, Accrued Interest on Unpaid Claims, Present Value of Future Expected Claims and Loss Expenses, Present Vlaue of Future Expected Recoveries and the related Unearned Premium Revenue liability.
Other Intangible Assets
Other Intangible Assets [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
All Trans
All Trans [Member]
All Trans
Schedule of Earnings Per Share, Basic and Diluted
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Executive Category:
Executive Category [Axis]
Ceded Reinsurance Premiums Written
Ceded Premiums Written
Ceded Premiums Written
Securities Financing Transaction [Domain]
Securities Financing Transaction [Domain]
Reconciliation of Common Shares Used for Basic and Diluted Earnings Per Share
Schedule of Weighted Average Number of Shares [Table Text Block]
Weighted average discounted rate of estimated future premium payments to be paid by the VIEs
Estimated Future Premium Payments Weighted Average Discounted Rate
Estimated Future Premium Payments Weighted Average Discounted Rate
Weighted average discounted rate of estimated future premium payments to be paid by the VIEs.
Level 1 [Member]
Fair Value, Inputs, Level 1 [Member]
Ambac Assurance [Member]
Ambac Assurance [Member]
Ambac assurance.
Reported Value Measurement [Member]
Priced Through Pricing Vendors [Member]
Reported Value Measurement [Member]
United Kingdom, Pounds
United Kingdom, Pounds
Hedge Funds, Multi-strategy [Member]
Hedge Funds, Multi-strategy [Member]
Equity Components [Axis]
Equity Components [Axis]
Financial Instruments [Domain]
Financial Instruments [Domain]
Additional 402(v) Disclosure
Additional 402(v) Disclosure [Text Block]
Other Derivatives [Member]
Other Credit Derivatives [Member]
Investment Type [Axis]
Investment Type [Axis]
Claim and loss expense payments, net of subrogation and reinsurance
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Current Year
Entity Small Business
Entity Small Business
Summary of Ceded Par and Net Unsecured Reinsurance Recoverable [Line Items]
Summary Of Ceded Par And Net Unsecured Reinsurance Recoverable [Line Items]
Summary of Ceded Par and Net Unsecured Reinsurance Recoverable [Line Items]
Investments [Domain]
Investments [Domain]
Local Phone Number
Local Phone Number
Recovery of Erroneously Awarded Compensation Disclosure [Line Items]
Notional outstanding
Derivative products, Notional Amount
Derivative, Notional Amount
Discount, gross claim liability
Schedule Of Insured Financial Obligations With Credit Deterioration Discount On Gross Claim Liability
This element represents the discounting on the gross claim liability for financial guarantee insurance contracts presented in the context of each surveillance grouping or category used by management to monitor and track potential deterioration in the credit worthiness of the insured party's ability to meet its financial obligations related to the contracts underlying financial guarantee insurance contracts the entity has issued.
Future premiums expected to be collected, December 31, 2055
Financial Guarantee Insurance Contract, Premium Receivable, to be Collected, after Year 30 Through 35
Measurement Frequency [Axis]
Measurement Frequency [Axis]
Investor Owned And Public Utilities [Member]
Investor Owned And Public Utilities [Member]
Investor Owned and Public Utilities [Member]
Restricted Cash and Cash Equivalents, Current
Restricted Cash and Cash Equivalents, Current
Retirement Plan Type [Domain]
Retirement Plan Type [Domain]
Restricted Stock Units (RSUs) [Member]
Restricted Stock Units (RSUs) [Member]
Forgone Recovery due to Violation of Home Country Law, Amount
Forgone Recovery due to Violation of Home Country Law, Amount
Components of VIE Gain (Loss) [Table Text Block]
Components of VIE Gain (Loss) [Table Text Block]
[Table Text Block] for Components of VIE Gain (Loss) [Table]
Depreciation
Depreciation
Number of Admitted Carriers Owned
Number of Admitted Carriers Owned
Number of Admitted Carriers Owned
Postemployment Benefits, Period Expense
Postemployment Benefits, Period Expense
Reportable Geographical Components [Member]
Reportable Geographical Components [Member]
Future expected premiums to be earned, net of reinsurance, December 31, 2045
Financial Guarantee Insurance Contract, Premium Revenue to be Recognized, after Year 20 Through 25
Portion at Fair Value Measurement [Member]
Portion at Fair Value Measurement [Member]
Reinsurance Recoverables on Unpaid Losses, Allowance
Reinsurance Recoverables on Unpaid Losses, Allowance
Ceded Credit Risk, Reinsurer [Axis]
Reinsurer, Name [Axis]
Schedule of Insured Financial Obligations with Credit Deterioration [Line Items]
Schedule of Insured Financial Obligations with Credit Deterioration [Line Items]
Equity Method Investments [Table Text Block]
Equity Method Investments [Table Text Block]
Derivative Liabilities
Variable Interest Entity Nonconsolidated Carrying Amount Derivative Net Assets Or Liabilities
The net carrying amount of derivative assets or liabilities in the reporting entity's statement of financial position that relate to the entity's variable interests in Variable Interest Entities (VIEs) where the VIEs are not consolidated.
Future premiums expected to be collected, December 31, 2022
Financial Guarantee Insurance Contract, Premium Receivable, to be Collected, Year Two
Amortized Cost, Due after ten years
Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 10
Total revenues and other income
Revenues
Revenues
Fair Value by Liability Class [Domain]
Fair Value by Liability Class [Domain]
Interest expense
Interest Expense, Debt
Collateralized Securities
Collateralized Securities [Member]
Aggregate Available
Trading Arrangement, Securities Aggregate Available Amount
Summary of Changes in Level 3 Fair Value Category
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Table Text Block]
Tabular presentation of Fair value assets and liabilities measured on recurring basis unobservable input reconciliation.
Insider Trading Policies and Procedures Not Adopted
Insider Trading Policies and Procedures Not Adopted [Text Block]
III [Member]
Surveillance Category Three [Member]
Surveillance category three.
Accretion of premium receivable discount
Financial Guarantee Insurance Contracts, Premiums Receivable, Adjustment, Accretion of Discount on Premium Receivable
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
Award Type [Axis]
Award Type [Axis]
Summary of Information Related to Policies Currently Included in Ambac's Loss Reserves or Subrogation Recoverable
Schedule of Insured Financial Obligations with Credit Deterioration [Table Text Block]
Document Quarterly Report
Document Quarterly Report
Global Public Finance [Member]
Global Public Finance [Member]
Global public finance.
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid
Fair Value Hierarchy and NAV [Domain]
Fair Value Hierarchy and NAV [Domain]
Consolidated Entities [Member]
Consolidated Entities [Member]
PEO Actually Paid Compensation Amount
PEO Actually Paid Compensation Amount
Derivatives, Fair Value [Line Items]
Derivatives, Fair Value [Line Items]
Schedule of Components of Income Tax Expense (Benefit)
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]
Additions for credit impairments recognized on:
Other Than Temporary Impairments Additions For Credit Impairments Recognized [Abstract]
Other than temporary impairments additions for credit impairments recognized.
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table]
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table]
Afg [Member]
Afg [Member]
Afg [Member]
Estimated Future Premium Payments Maximum Discounted Rate
Accounts Payable
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Reclassification Adjustment from AOCI for Derecognition, before Tax
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Reclassification Adjustment from AOCI for Derecognition, before Tax
Gross claim liability, net of all subrogation and discounts, before reinsurance
Schedule of Insured Financial Obligations with Credit Deterioration, Net Claim Liability
Unearned premiums
Unearned Premiums
Finite-Lived Intangible Assets, Net
Finite-Lived Intangible Assets, Net
Parsed Investment Type [Domain]
Parsed Investment Type [Domain]
Parsed Investment Type [Domain]
Managing General Agency Underwriter
Managing General Agency Underwriter [Member]
Managing General Agency Underwriter
New Accounting Pronouncements, Policy [Policy Text Block]
New Accounting Pronouncements, Policy [Policy Text Block]
Temporary Equity, Accretion to Redemption Value, Adjustment
Temporary Equity, Accretion to Redemption Value, Adjustment
Internal Credit Assessment [Axis]
Internal Credit Assessment [Axis]
Segment Reporting, Revenue Reconciling Item [Line Items]
Segment Reporting, Revenue Reconciling Item [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization
Finite-Lived Intangible Assets, Accumulated Amortization
Insurance [Abstract]
Insurance [Abstract]
Housing Revenue [Member]
Housing Revenue [Member]
Housing Revenue [Member]
Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]
Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]
Business Combination, AAC Cash Consideration for Beat Acquisition
Business Combination, AAC Cash Consideration for Beat Acquisition
Business Combination, AAC Cash Consideration for Beat Acquisition
Stock Price or TSR Estimation Method
Stock Price or TSR Estimation Method [Text Block]
Income (Loss) from Continuing Operations before Income Taxes, Foreign
Income (Loss) from Continuing Operations before Income Taxes, Foreign
Mortgage And Other Asset Backed Securities [Member]
Mortgage And Other Asset Backed Securities [Member]
Mortgage And Other Asset Backed Securities [Member]
Insurance Intangible Asset [Member]
Insurance Intangible Asset [Member]
Insurance Intangible Asset [Member]
Business Combination, Consideration Transferred
Business Combination, Consideration Transferred
Amortized Cost, Total
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Amortized Cost
Security Exchange Name
Security Exchange Name
Ceded Credit Risk, Reinsurer [Domain]
Reinsurer, Name [Domain]
Investment Income [Table]
Investment Income [Table]
Background And Basis Of Presentation [Line Items]
Background And Basis Of Presentation [Line Items]
Background And Basis Of Presentation [Line Items]
Future premiums expected to be collected, December 31, 2021
Financial Guarantee Insurance Contract, Premium Receivable, to be Collected, Fourth Quarter
Accumulated other comprehensive income
Beginning Balance
Ending Balance
Accumulated Other Comprehensive Income (Loss), Net of Tax
Past Due Premiums
Past Due Premiums
Past Due Premiums
Other comprehensive income before reclassifications
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax
Employee Stock Option
Share-Based Payment Arrangement, Option [Member]
Derivative Instruments
Derivative Instruments and Hedging Activities Disclosure [Text Block]
Maximum [Member]
Maximum [Member]
Document Type
Document Type
Goodwill, Acquired During Period
Goodwill, Acquired During Period
Reclassification out of Accumulated Other Comprehensive Income [Table]
Reclassification out of Accumulated Other Comprehensive Income [Table]
Total expenses
Benefits, Losses and Expenses
Benefits, Losses and Expenses
Tabular List, Table
Tabular List [Table Text Block]
Currency Swaps [Member]
Currency Swap [Member]
Treasury Stock, Value, Acquired, Cost Method
Treasury Stock, Value, Acquired, Cost Method
Maximum Exposure To Loss
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount
Antidilutive Securities, Name [Domain]
Antidilutive Securities, Name [Domain]
Current Federal Tax Expense (Benefit)
Current Federal Tax Expense (Benefit)
Capitalized Contract Cost, Net
Capitalized Contract Cost, Net
Purchases of bonds
Payments to Acquire Debt Securities, Available-for-Sale
Net investment income:
Net Investment Income [Abstract]
Business Acquisition [Axis]
Business Acquisition [Axis]
Net Realized and Unrealized Gain (Loss) on Trading Securities
Debt Securities, Trading, Gain (Loss)
Other assets
Fair value of special purpose entities
Equity Method Investments, Fair Value Disclosure
Derivative [Table]
Derivative [Table]
Gains (losses) on securities held as of reporting date [Member]
Gains (losses) on securities held as of reporting date [Member]
Gains (losses) on securities held as of reporting date [Member]
Future premiums expected to be collected, December 31, 2024
Financial Guarantee Insurance Contract, Premium Receivable, to be Collected, Year Four
Net investment income
Net Investment Income
Net Investment Income
Title of 12(b) Security
Title of 12(b) Security
Loss Contingency, Nature [Domain]
Loss Contingency, Nature [Domain]
Business Combination Disclosure
Business Combination Disclosure [Text Block]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill
Indefinite-Lived Intangible Assets (Excluding Goodwill)
Aggregate Erroneous Compensation Not Yet Determined
Aggregate Erroneous Compensation Not Yet Determined [Text Block]
Debt Securities, Available for sale, Unrealized Loss Position, Including Pledged Securities
Debt Securities, Available for sale, Unrealized Loss Position, Accumulated Loss, Less than 12 Months, Including Pledged Securities
Debt Securities, Available for sale, Unrealized Loss Position, Accumulated Loss, Less than 12 Months, Including Pledged Securities
Noncontrolling Interest in Net Income (Loss) Other Noncontrolling Interests, Nonredeemable
Noncontrolling Interest in Net Income (Loss) Other Noncontrolling Interests, Nonredeemable
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Abstract]
Forgone Recovery due to Expense of Enforcement, Amount
Forgone Recovery due to Expense of Enforcement, Amount
Liability for Unpaid Claims and Claims Adjustment Expense, Foreign Currency Translation Gain (Loss)
Liability for Unpaid Claims and Claims Adjustment Expense, Foreign Currency Translation Gain (Loss)
Unrealized (loss) gain on securities, taxes
OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, Tax
Debt Securities , Available for sale, Continuous Unrealized Loss Position,
Debt Securities , Available for sale, Continuous Unrealized Loss Position,
Debt Securities , Available for sale, Continuous Unrealized Loss Position, Less than 12 Months, Including Pledged Securities
Entity Tax Identification Number
Entity Tax Identification Number
Statistical Measurement [Axis]
Statistical Measurement [Axis]
External Credit Rating, Non Investment Grade [Member]
External Credit Rating, Non Investment Grade [Member]
Balance Sheet Location [Domain]
Balance Sheet Location [Domain]
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, before Tax, after Reclassification Adjustment
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, before Tax
Entity Interactive Data Current
Entity Interactive Data Current
Schedule of Available-for-sale Securities [Table]
Debt Securities, Available-for-Sale [Table]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Other Assets [Member]
Other Assets [Member]
Reinsurance Recoverables, Gross
Reinsurance Recoverables, Gross
Measure:
Measure [Axis]
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Abstract]
Name
Outstanding Recovery, Individual Name
Other Debt Obligations [Member]
Other [Member]
Other Debt Obligations [Member]
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss)
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss)
Entity Incorporation, State or Country Code
Entity Incorporation, State or Country Code
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Internal Credit Assessment [Domain]
Internal Credit Assessment [Domain]
Common stock, shares outstanding
Common Stock, Shares, Outstanding
Reinsurance Recoverables, Including Reinsurance Premium Paid
Reinsurance Recoverables, Including Reinsurance Premium Paid
Other investments
Other Investments
Investments [Member]
Investments [Member]
PEO
PEO [Member]
Other Cost and Expense, Operating
Other Cost and Expense, Operating
Other International [Member]
Other International [Member]
Other international.
Loss Reserves [Member]
Loss Reserves Claim Liability [Member]
Loss Reserves Claim Liability [Member]
Schedule of Variable Interest Entities [Table]
Schedule of Variable Interest Entities [Table]
Common Stock, Par or Stated Value Per Share
Common stock, par value
Par value of common stock issued
Common Stock, Par or Stated Value Per Share
Uncollateralized Credit Exposure Supoorted by Unlimited Uncapped Indemnity
Uncollateralized Credit Exposure Supoorted by Unlimited Uncapped Indemnity
Uncollateralized Credit Exposure Supoorted by Unlimited Uncapped Indemnity
Net cash provided by (used in) investing activities
Net Cash Provided by (Used in) Investing Activities
Variable Interest Entity Change in Fair Value of Assets and Liabilities
Variable Interest Entity Change in Fair Value of Assets and Liabilities
Variable Interest Entity Change in Fair Value of Assets and Liabilities
Interest Rate Swap [Member]
Interest Rate Swap [Member]
Gross Amount of Collateral Received/Pledged Not Offset in the Consolidated Balance Sheet, Derivative Liabilities
Derivative Liabilities Gross Amount Of Collateral Cash And Securities Pledged Not Offset
Derivative Liabilities Gross Amount Of Collateral Cash And Securities Pledged Not Offset
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions
Debt Instrument [Axis]
Debt Instrument [Axis]
Outstanding Aggregate Erroneous Compensation Amount
Outstanding Aggregate Erroneous Compensation Amount
Public Finance [Member]
Public Finance [Member]
Public Finance [Member]
Liabilities for net financial guarantees written
Guarantees, Fair Value Disclosure
Total liabilities
Liabilities
Liabilities
Current Income Tax Expense (Benefit)
Current Income Tax Expense (Benefit)
Debt Securities, Available-for-sale, Unrealized Loss Position
Debt Securities, Available-for-Sale, Unrealized Loss Position
Net Investment Income [Member]
Investment Income [Member]
Measurement Frequency [Domain]
Measurement Frequency [Domain]
Class of Financing Receivable [Axis]
Class of Financing Receivable [Axis]
Non-Rule 10b5-1 Arrangement Adopted
Non-Rule 10b5-1 Arrangement Adopted [Flag]
Assumed Reinsurance Premiums Earned
Assumed Premiums Earned
VIE Change in FV of Assets Liabilities, Net of Credit Risk Change
VIE Change in FV of Assets Liabilities, Net of Credit Risk Change
VIE Change in FV of Assets Liabilities, Net of Credit Risk Change
External Credit Rating, Moody's [Domain]
External Credit Rating, Moody's [Domain]
Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table]
Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table]
Weighted average period of future premiums
Financial Guarantee Insurance Contracts, Premium Received over Contract Period, Premium Receivable, Weighted Average Collection Period
US Government Debt Securities [Member]
US Government Debt Securities [Member]
Change in cash collateral
Increase (Decrease) Cash Collateral from Counterparties
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months
General and Administrative Expense
General and Administrative Expense
Summary of Gross Unrealized Losses and Fair Values of Ambac's Available-for-Sale Investments
Schedule of Unrealized Loss on Investments [Table Text Block]
Future expected premiums to be earned, net of reinsurance, September 30, 2021
Financial Guarantee Insurance Contract, Premium Revenue to be Recognized, Third Quarter
Awards Close in Time to MNPI Disclosures, Table
Awards Close in Time to MNPI Disclosures [Table Text Block]
Current State and Local Tax Expense (Benefit)
Current State and Local Tax Expense (Benefit)
Allowance for Doubtful Accounts, Premiums and Other Receivables
Allowance for Doubtful Accounts, Premiums and Other Receivables
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Table]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Table]
Contract with Customer, Receivable, after Allowance for Credit Loss
Contract with Customer, Receivable, after Allowance for Credit Loss
Segment Reporting, Policy
Segment Reporting, Policy [Policy Text Block]
Riverton
Riverton [Member]
Riverton
Preferred Stock [Member]
Preferred Stock [Member]
Professional Liability
Professional Liability [Member]
Professional Liability
Business Disposal, AAC Accumulated Other Comprehensive Loss
Business Disposal, AAC Accumulated Other Comprehensive Loss
Business Disposal, AAC Accumulated Other Comprehensive Loss
Credit Derivatives Contract Type [Domain]
Credit Derivatives Contract Type [Domain]
Contractually Specified Servicing Fee, Late Fee, and Ancillary Fee Earned in Exchange for Servicing Financial Asset
Contractually Specified Servicing Fee, Late Fee, and Ancillary Fee Earned in Exchange for Servicing Financial Asset
Other liabilities
Other Liabilities
Other Liabilities
Goodwill and Intangible Assets Disclosure
Goodwill and Intangible Assets Disclosure [Text Block]
Future premiums expected to be collected, December 31, 2035
Financial Guarantee Insurance Contract, Premium Receivable, to be Collected, after Year 10 Through 15
IA [Member]
Surveillance Category Onea [Member]
Surveillance Category OneA [Member]
Subrogation recoverable
Subrogation recoverable
Subrogation recoverable
Salvage and Subrogation Recoveries, Value
Capacity Marine
Capacity Marine [Member]
Capacity Marine
Schedule of Changes in Balances of Each Component of Accumulated Other Comprehensive Income
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]
Insurance Commissions and Fees
Insurance Commissions and Fees
Total investments (net of allowance for credit losses of $3 and $3)
Investments
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
US Treasury and Government
US Treasury and Government [Member]
Percentage of investment portfolio valued using external pricing services
Percentage Of Investment Portfolio Valued Using External Pricing Services
Percentage of investment portfolio valued using external pricing services.
Other Postretirement Benefits Plan [Member]
Other Postretirement Benefits Plan [Member]
Asset-backed Securities [Member]
Asset-Backed Securities [Member]
Other income Items
Other income Items
Other income Items
Net Cash Provided by (Used in) Operating Activities, Total
Net Cash Provided by (Used in) Operating Activities
Debt Securities Available for Sale Unrealized Loss Measured as a Percent of Amortized Cost
Debt Securities Available for Sale Unrealized Loss Measured as a Percent of Amortized Cost
Debt Securities Available for Sale Unrealized Loss Measured as a Percent of Amortized Cost
Class of Stock [Axis]
Class of Stock [Axis]
Unsecured Reinsurance Recoverables
Unsecured Reinsurance Recoverables
Represents reinsurance recoverables on paid and unpaid losses and deferred ceded premiums, net of ceded premiums payables due to reinsurers, letters of credit, and collateral posted for the benefit of the cedant.
Entities [Table]
Entities [Table]
Erroneously Awarded Compensation Recovery
Erroneously Awarded Compensation Recovery [Table]
Insurance Linked [Member]
Insurance Linked [Member]
Insurance Linked [Member] [Member]
Other Operating Income (Expense), Net
Other Operating Income (Expense), Net
Award Timing, How MNPI Considered
Award Timing, How MNPI Considered [Text Block]
Schedule Of Earnings Per Share [Line Items]
Schedule Of Earnings Per Share [Line Items]
Schedule Of Earnings Per Share [Line Items]
Derivative Asset, Fair Value, Amount Not Offset Against Collateral
Derivative Asset, Subject to Master Netting Arrangement, before Offset of Collateral
Entity Information [Line Items]
Entity Information [Line Items]
Postemployment Benefits [Abstract]
Debt Securities, Available-for-sale, Realized Gain
Debt Securities, Available-for-Sale, Realized Gain
Financing Receivable, after Allowance for Credit Loss
Loans
Financing Receivable, after Allowance for Credit Loss
Premium receipts
Financial Guarantee Insurance Contracts, Premium Receivable, Proceeds from Premiums Received
Consolidation Items [Axis]
Consolidation Items [Axis]
Number of Reinsurers Covering Majority
Number of Reinsurers Covering Majority
Number of Reinsurers Covering Majority
Goodwill, Impairment Loss
Goodwill, Impairment Loss
Contract with Customer, Liability, Revenue Recognized
Contract with Customer, Liability, Revenue Recognized
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax
Determination Date [Domain]
Determination Date [Domain]
[Domain] for Determination Date [Axis]
Provision for Income Taxes [Table]
Provision for Income Taxes [Table]
Provision for Income Taxes [Table]
Future premiums expected to be collected, December 31, 2025
Financial Guarantee Insurance Contract, Premium Receivable, to be Collected, Year Five
Accumulated Gain (Loss), Financial Liability, Fair Value Option, Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Gain (Loss), Financial Liability, Fair Value Option, Including Portion Attributable to Noncontrolling Interest [Member]
Schedule of Insured Financial Obligations with Credit Deterioration [Table]
Schedule of Insured Financial Obligations with Credit Deterioration [Table]
Financing Receivable, 90 Days or More Past Due, Still Accruing
Financing Receivable, 90 Days or More Past Due, Still Accruing
Preferred Stock, Shares Issued
Preferred Stock, Shares Issued
Business Disposal, Life of Warrants Issued in Connection with AAC Disposal
Business Disposal, Life of Warrants Issued in Connection with AAC Disposal
Business Disposal, Life of Warrants Issued in Connection with AAC Disposal
Entity Emerging Growth Company
Entity Emerging Growth Company
United Kingdom [Member]
UNITED KINGDOM
Intangible assets, less accumulated amortization
Intangible Assets, Net (Excluding Goodwill)
Future premiums expected to be collected, Total
Financial Guarantee Insurance Contracts, Premium Receivable, Premium Expected to be Collected
Other Structured Finance [Member]
Other Structured Finance [Member]
Other Structured Finance [Member]
Real Estate Funds
Real Estate Funds [Member]
Noncontrolling Interest Policy
Noncontrolling Interest Policy [Policy Text Block]
Noncontrolling Interest Policy
Pay vs Performance Disclosure, Table
Pay vs Performance [Table Text Block]
Antidilutive Securities [Axis]
Antidilutive Securities [Axis]
Number of Variable Interest Entities Deconsolidated During Period
Number of Variable Interest Entities Deconsolidated During Period
Number of Variable Interest Entities Deconsolidated During Period
Title
Trading Arrangement, Individual Title
Common Stock [Member]
Common Stock [Member]
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax
Individual:
Individual [Axis]
Entity Address, Postal Zip Code
Entity Address, Postal Zip Code
Income Statement Location [Domain]
Income Statement Location [Domain]
Loss and loss expense reserves
Liability for Claims and Claims Adjustment Expense, Financial Guarantee Insurance Contracts
Repayments of Secured Debt
Repayments of Secured Debt
Repayments of Secured Debt
Schedule of Income Before Income Tax, Domestic and Foreign [Line Items]
Schedule of Income Before Income Tax, Domestic and Foreign [Line Items]
[Line Items] for Schedule of Income Before Income Tax, Domestic and Foreign [Table]
Securities acquired (transferred) in connection with financial guarantee commutations
Securities acquired (transferred) in connection with financial guarantee commutations
Securities acquired (transferred) in connection with financial guarantee commutations
Total stockholders’ equity
Beginning balance
Ending balance
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest
Equity, Including Portion Attributable to Noncontrolling Interest
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders
Derivative Liabilities Net Amount
Derivative Liabilities Net Amount
Derivative Liabilities Net Amount
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest
Minimum [Member]
Minimum [Member]
Other Investment Not Readily Marketable, Fair Value
Other Investment Not Readily Marketable, Fair Value
Document And Entity Information [Abstract]
Document And Entity Information [Abstract]
Document and Entity Information [Abstract]
Total other comprehensive income (loss), net of income tax
Other Comprehensive Income (Loss), Net of Tax
Statement of Cash Flows [Abstract]
Statement of Cash Flows [Abstract]
Assets:
Assets [Abstract]
Award Timing MNPI Disclosure
Award Timing MNPI Disclosure [Text Block]
Marine
Marine [Member]
Marine
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims
Business Disposal, Termination Fee
Business Disposal, Termination Fee
Business Disposal, Termination Fee
Estimated Fair Value, Due after ten years
Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10
Foreign Currency Transaction Gain (Loss), before Tax
Foreign exchange (losses) gains
Gain (Loss), Foreign Currency Transaction, before Tax
Tax payments related to shares withheld for share-based compensation plans
Payment, Tax Withholding, Share-Based Payment Arrangement
Liabilities:
Liabilities [Abstract]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Interest Rate Swaps-Pay-Fixed/Receive-Variable [Member]
Interest Rate Swap One [Member]
Interest rate swap one.
Net cash used in financing activities
Net Cash Provided by (Used in) Financing Activities
Retirement Plan Type [Axis]
Retirement Plan Type [Axis]
Commitments and Contingencies
Commitments and Contingencies Disclosure [Text Block]
Other, net
Payments for (Proceeds from) Other Investing Activities
Payments to Acquire Interest in Subsidiaries and Affiliates
Payments to Acquire Interest in Subsidiaries and Affiliates
Business Acquisition, Percentage of Voting Interests Acquired
Business Acquisition, Percentage of Voting Interests Acquired
Retained Earnings [Member]
Retained Earnings [Member]
Remaining weighted-average contract period (in years)
Insured Financial Obligations with Credit Deterioration, Remaining Weighted Average Contract Period
Fixed Income Investments [Member]
Fixed Income Investments [Member]
Adjustment to Non-PEO NEO Compensation Footnote
Adjustment to Non-PEO NEO Compensation Footnote [Text Block]
Deferred Ceded Premiums And Reinsurance Recoverables
Deferred Ceded Premiums And Reinsurance Recoverables
Includes the unexpired portion of financial guarantee premiums ceded on policies as of the balance sheet date and reinsurance recoverables on claims or claim adjustment expense paid by the ceding insurer.
External Credit Rating by Grouping [Domain]
External Credit Rating by Grouping [Domain]
Earnings Per Share, Basic
Earnings Per Share, Basic
Earnings Per Share, Basic
Accounting Policies [Abstract]
Accounting Policies [Abstract]
Erroneous Compensation Analysis
Erroneous Compensation Analysis [Text Block]
Xchange
Xchange [Member]
Xchange
Premium Receivable, Allowance for Credit Loss
Uncollectable premium receivables
Premium Receivable, Allowance for Credit Loss
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, Tax
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, Tax
Private Equity Funds [Member]
Private Equity Funds [Member]
Gain (Loss) on Derivative Instruments [Member]
Gain (Loss) on Derivative Instruments [Member]
Income (loss) on variable interest entities
Variable interest entity activities
Variable Interest Entity, Measure of Activity, Operating Income or Loss
Fixed Income Investments [Member]
Available-for-Sale Securities [Member]
Assumed Reinsurance Premiums Written
Assumed Premiums Written
Income Taxes Paid
Income Taxes Paid
Consolidation, Policy
Consolidation, Policy [Policy Text Block]
Entity Ex Transition Period
Document Transition Report
Award Timing Predetermined
Award Timing Predetermined [Flag]
Interest Expense
Interest Expense [Member]
Uncollectable premiums
Premium Receivable, Allowance for Credit Loss, Period Increase (Decrease)
Debt Security Category [Domain]
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Categories of Investments [Domain]
Summary of Net Investment Income
Investment Income [Table Text Block]
IV [Member]
Surveillance Category Four [Member]
Surveillance category four.
Derivative Instrument [Axis]
Derivative, by Nature [Axis]
Derivative Instrument [Axis]
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments
Liability Class [Axis]
Liability Class [Axis]
All Trading Arrangements
All Trading Arrangements [Member]
Amortized Cost, Due in one year or less
Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One
All Adjustments to Compensation
All Adjustments to Compensation [Member]
Compensation Amount
Outstanding Recovery Compensation Amount
Operating Loss Carryforwards, Expiration Date
Operating Loss Carryforwards, Expiration Date
Premium Receivable, Allowance for Credit Loss, Writeoff
Premium Receivable, Allowance for Credit Loss, Writeoff
Derivative assets
Net Amounts of Assets Presented in the Consolidated Balance Sheet, Derivative Assets
Derivative Asset
Deferred Income Tax Expense (Benefit)
Deferred Income Tax Expense (Benefit)
Catastrophic Event [Axis]
Subsequent Event Type [Axis]
Premiums Written, Gross
Premiums Written, Gross
Future premiums expected to be collected, December 31, 2045
Financial Guarantee Insurance Contract, Premium Receivable, to be Collected, after Year 20 Through 25
Summary of Gross Fair Values of Individual Derivative Instruments
Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location [Table Text Block]
PWIC
PWIC [Member]
PWIC
Future expected premiums to be earned, net of reinsurance, December 31, 2040
Financial Guarantee Insurance Contract, Premium Revenue to be Recognized, after Year 15 Through 20
Number Of Consolidated Variable Interest Entities
Number Of Consolidated Variable Interest Entities
Number of consolidated variable interest entities.
Other assets
Other Assets
Coupon rate
Fair Value Inputs Coupon Rate
Fair Value Inputs Coupon Rate
Fair value inputs coupon rate.
Long Term Debt Unpaid Principal Balance
Long Term Debt Unpaid Principal Balance
This represents the amount of principal outstanding on long-term debt that is presented on the balance sheet at fair value, whether such presentation is as a separate caption or parenthetical disclosure.
Standard & Poor's, A+ Rating
Standard & Poor's, A+ Rating [Member]
Business Combination, Volume Weighted Average Price
Business Combination, Volume Weighted Average Price
Business Combination, Volume Weighted Average Price
Global Structured Finance [Member]
Global Structured Finance [Member]
Global structured finance.
Document Period End Date
Document Period End Date
Schedule of Income Before Income Tax, Domestic and Foreign [Table]
Schedule of Income Before Income Tax, Domestic and Foreign [Table]
Schedule of Income Before Income Tax, Domestic and Foreign [Table]
Adoption Date
Trading Arrangement Adoption Date
Losses and loss expense reserves ceded to reinsurers
Loss Reserves Ceded To Reinsurers
Loss Reserves Ceded To Reinsurers
The known and estimated amount recoverable as of the balance sheet date from reinsurers for claims expected to be paid or incurred by the ceding insurer.
Business Combination, Consideration Paid in Cash
Business Combination, Consideration Paid in Cash
Business Combination, Consideration Paid in Cash
Fair Value of Securities Deposited in Connection wtih Letter of Credit
Fair Value of Securities Deposited in Connection wtih Letter of Credit
Fair Value of Securities Deposited in Connection wtih Letter of Credit
Direct Premiums Written
Direct Premiums Written
Treasury Stock, Common
Treasury Stock, Common [Member]
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reinsurance recoverable reported on Balance Sheet
Schedule of Insured Financial Obligations with Credit Deterioration, Statement of Financial Position, Reinsurance Recoverable
Tier 2 Notes
Tier 2 Notes [Member]
Tier 2 Notes
Business Disposal, Warrant Strike Price in Connection with Disposal
Business Disposal, Warrant Strike Price in Connection with Disposal
Business Disposal, Warrant Strike Price in Connection with Disposal
Principal
Schedule of Insured Financial Obligations with Credit Deterioration, Insured Contractual Payments Outstanding, Principal
Loss Contingency Nature [Axis]
Loss Contingency Nature [Axis]
Provision for income taxes
Income Tax Expense (Benefit)
Income tax expense (benefit)
Income Tax Expense (Benefit)
Interest Income, Debt Securities, Available-for-Sale, Operating
Interest Income, Debt Securities, Available-for-Sale, Operating
Insurance [Line Items]
Insurance [Line Items]
Insurance [Line Items]
Fair Value Measurements
Fair Value Disclosures [Text Block]
Business Disposal, Percent of Common Shares Issued in Connection with Disposal
Business Disposal, Percent of Common Shares Issued in Connection with Disposal
Business Disposal, Percent of Common Shares Issued in Connection with Disposal
Amounts reclassified from accumulated other comprehensive income
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax
Fixed Income Securities, Trading
Fixed Income Securities, Trading [Member]
Fixed Income Securities, Trading
Loss And Loss Adjustment Expense Reserves [Line Items]
Loss And Loss Adjustment Expense Reserves [Line Items]
Loss And Loss Adjustment Expense Reserves [Line Items]
Future expected premiums to be earned, net of reinsurance, December 31, 2030
Financial Guarantee Insurance Contract, Premium Revenue to be Recognized, after Year 5 Through 10
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss
Equity [Abstract]
Equity [Abstract]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale [Line Items]
Compensation Actually Paid vs. Company Selected Measure
Compensation Actually Paid vs. Company Selected Measure [Text Block]
Gross claim liability before all subrogation and before reinsurance
Schedule of Insured Financial Obligations with Credit Deterioration, Gross Claim Liability
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss
Cash and Cash Equivalents, at Carrying Value
Cash and Cash Equivalents, at Carrying Value
Total comprehensive income (loss), net of income tax
Total comprehensive income (loss)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest
Discount, other subrogation
Schedule Of Insured Financial Obligations With Credit Deterioration Reductions Of Gross Claim Liability Discount On Other Subrogation
This element represents the discount on the gross subrogation on insured financial obligations with credit deterioration, excluding the discount on the gross subrogation on insured RMBS financial obligations with credit deterioration.
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Tax Effect
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Plan Amendments, Tax Effect
Components of Loss and Loss Expense Reserves and Subrogation Recoverable [Table]
Components of Loss and Loss Expense Reserves and Subrogation Recoverable [Table]
Components of Loss and Loss Expense Reserves and Subrogation Recoverable [Table]
Derivative Asset, Fair Value, Amount Offset Against Collateral
Derivative Asset, Including Not Subject to Master Netting Arrangement, after Offset and Deduction
Compensation Actually Paid vs. Other Measure
Compensation Actually Paid vs. Other Measure [Text Block]
External Credit Rating, Investment Grade
External Credit Rating, Investment Grade [Member]
Interest Rate Contract [Member]
Interest Rate Contract [Member]
Discounted other subrogation, before reinsurance
Schedule Of Insured Financial Obligations With Credit Deterioration Reductions Of Gross Claim Liability Other Subrogation
This element represents the reduction to gross claim liability for subrogation on insured financial obligations with credit deterioration, excluding the reduction to gross claim liability for subrogation on insured RMBS financial obligations with credit deterioration.
Contract with Customer, Contract Asset, Contract Liability, and Receivable
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]
Property and Casualty, Commercial Insurance
Property and Casualty, Commercial Insurance [Member]
Revenue from Contract with Customer
Revenue from Contract with Customer [Text Block]
Additional Paid-in Capital [Member]
Additional Paid-in Capital [Member]
Effect of potential dilutive shares:
Weighted Average Number of Shares Outstanding, Diluted, Adjustment [Abstract]
Present Value of Expected Net Cash Flows-Recoveries [Member]
Present Value of Expected Net Cash Flows-Recoveries [Member]
Recoveries [Member]
Balance Sheet Location [Axis]
Balance Sheet Location [Axis]
Equity Securities, FV-NI, Realized Gain (Loss)
Equity Securities, FV-NI, Realized Gain (Loss)
Restatement [Axis]
Revision of Prior Period [Axis]
Insurance Commissions
Insurance Commissions
Direct Premiums Earned
Direct Premiums Earned
Premiums Receivable, Net
Premiums Receivable, Net
United States [Member]
UNITED STATES
Tax Credit Carryforward, Name [Domain]
Tax Credit Carryforward, Name [Domain]
Fair Value, Recurring [Member]
Fair Value, Recurring [Member]
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]
Short-term Investments
Short-Term Investments
Number of Variable Interest Entities Consolidated During the Period
Number of Variable Interest Entities Consolidated During the Period
Number of Variable Interest Entities Consolidated During the Period
Compensation and Employee Benefit Plans
Compensation and Employee Benefit Plans [Text Block]
Segment Reporting Disclosure
Segment Reporting Disclosure [Text Block]
Foreign Obligations [Member]
Debt Security, Government, Non-US [Member]
Debt Security, Government, Non-US [Member]
Net cash flow
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect
Percentage of Ceded Reinsurance Recoverable Represented by Top Three
Percentage of Ceded Reinsurance Recoverable Represented by Top Three
Percentage of Ceded Reinsurance Recoverable Represented by Top Three
Equity Component [Domain]
Equity Component [Domain]
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held
The amount of gains or losses included in earnings attributable to unrealized gains or losses on financial instruments measured on a recurring basis using unobservable inputs that are still held at the reporting date.
Unearned Premium Reserve [Member]
Unearned Premium Reserve [Member]
Unearned Premium Reserve [Member]
Mortgage-Backed Securities, Other
Mortgage-Backed Securities, Other [Member]
Summary of Fair Value, Including Financial Guarantee, and Weighted-Average Underlying Rating, Excluding Financial Guarantee, of Insured Securities
Fair Value And Weighted Average Underlying Rating Of Securities Covered By Guarantees Table [Text Block]
Fair Value And Weighted Average Underlying Rating Of Securities Covered by Guarantees [Table Text Block]
Non-GAAP Measure Description
Non-GAAP Measure Description [Text Block]
Entity Current Reporting Status
Entity Current Reporting Status
Ambac UK [Member]
Ambac Uk [Member]
Ambac UK [Member]
Realized Investment Gains (Losses)
Net investment gains (losses), including impairments
Realized Investment Gains (Losses)
I/SL [Member]
Surveillance Category One [Member]
Surveillance Category One [Member]
Consolidated Entities [Domain]
Variable Interest Entity, Classification [Domain]
Consolidated Entities [Domain]
Segments [Axis]
Segments [Axis]
Total Fair Value [Member]
Estimate of Fair Value Measurement [Member]
Convertibles and Bonds with Warrants Attached
Convertibles and Bonds with Warrants Attached [Member]
Other comprehensive income (loss), after tax
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Ceded premiums payable
Increase (Decrease) in Reinsurance Payables
Scenario [Domain]
Scenario [Domain]
Forgone Recovery due to Disqualification of Tax Benefits, Amount
Forgone Recovery due to Disqualification of Tax Benefits, Amount
Collateralized Mortgage Backed Securities [Member]
Collateralized Mortgage-Backed Securities [Member]
Awards Close in Time to MNPI Disclosures
Awards Close in Time to MNPI Disclosures [Table]
Sovereign And Sub Sovereign [Member]
Sovereign And Sub Sovereign [Member]
Sovereign And Sub Sovereign [Member]
Standard & Poor's, AA+ Rating
Standard & Poor's, AA+ Rating [Member]
Stockholders’ equity:
Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Future expected premiums to be earned, net of reinsurance, December 31, 2023
Financial Guarantee Insurance Contract, Premium Revenue to be Recognized, Year Three
Debt Securities, Available-for-sale, Allowance for Credit Loss, Sell before Recovery
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Sell before Recovery
Adjustments for Change in Accounting Principle [Axis]
Change in Accounting Principle, Type [Axis]
Consolidated Entities [Axis]
Consolidated Entities [Axis]
Pay vs Performance Disclosure [Line Items]
Statistical Measurement [Domain]
Statistical Measurement [Domain]
Credit Deterioration Surveillance Category [Axis]
Credit Deterioration Surveillance Category [Axis]
Equity [Member]
Equity [Member]
Underlying Security Market Price Change
Underlying Security Market Price Change, Percent
Reinsurance Recoverable, Gross, All Other
Reinsurance Recoverable, Gross, All Other
Reinsurance Recoverable, Gross, All Other
Assured Guaranty Re Ltd
Assured Guaranty Re Ltd [Member]
Assured Guaranty Re Ltd [Member]
Statement of Stockholders' Equity [Abstract]
Statement of Stockholders' Equity [Abstract]
AFS [Member]
Afs [Member]
AFS.
Investments, Debt and Equity Securities [Abstract]
Investments, Debt and Equity Securities [Abstract]
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Primary Beneficiary [Member]
Effect of foreign exchange on cash, cash equivalents and restricted cash
Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Continuing Operations
Future expected premiums to be earned, net of reinsurance, Total
Financial Guarantee Insurance Contracts, Unearned Premium Revenue
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments and Joint Ventures [Abstract]
MNPI Disclosure Timed for Compensation Value
MNPI Disclosure Timed for Compensation Value [Flag]
Performance Shares [Member]
Performance Shares [Member]
Segment Reporting [Abstract]
Restatement Determination Date:
Restatement Determination Date [Axis]
Collateralized Debt Obligations [Member]
Collateralized Debt Obligations [Member]
Summary of Location and Amount of Gains and Losses of Derivative Contracts
Derivatives Not Designated as Hedging Instruments [Table Text Block]
Corporate Debt Securities [Member]
Corporate Obligations [Member]
Corporate Debt Securities [Member]
Provision for Income Taxes [Line Items]
Provision for Income Taxes [Line Items]
[Line Items] for Provision for Income Taxes [Table]
Business Disposal, Carrying Value of AAC
Business Disposal, Carrying Value of AAC
Business Disposal, Carrying Value of AAC
Tax Credit Carryforward [Table]
Tax Credit Carryforward [Table]
Average Percentage of Unrealized Loss Versus Amortized Cost for Investment Grade Securities
Average Percentage of Unrealized Loss Versus Amortized Cost for Investment Grade Securities
Average Percentage of Unrealized Loss Versus Amortized Cost for Investment Grade Securities
Geographical [Axis]
Geographical [Axis]
II [Member]
Surveillance Category Two [Member]
Surveillance category two.
Income Taxes
Income Tax Disclosure [Text Block]
Liability for Claims and Claims Adjustment Expense
Liability for Claims
Liability for Claims and Claims Adjustment Expense
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Table]
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Table]
Unearned premiums, net
Increase (Decrease) in Unearned Premiums
Losses and loss adjustment expenses (benefit)
Policyholder Benefits and Claims Incurred, Net, Financial Guarantee
Guarantor Obligations, Nature [Axis]
Guarantor Obligations, Nature [Axis]
Preferred stock, par value
Preferred Stock, Par or Stated Value Per Share
Employer Stop Loss
Employer Stop Loss [Member]
Employer Stop Loss
Fair Value, Recurring and Nonrecurring [Table]
Fair Value, Recurring and Nonrecurring [Table]
Average Percentage of Unrealized Loss Versus Amortized Cost for Below Investment Grade Securities
Average Percentage of Unrealized Loss Versus Amortized Cost for Below Investment Grade Securities
Average Percentage of Unrealized Loss Versus Amortized Cost for Below Investment Grade Securities
Derivative liabilities
Derivative Liability, Subject to Master Netting Arrangement, before Offset
PEO Total Compensation Amount
PEO Total Compensation Amount
Foreign Currency [Abstract]
Foreign Currency [Abstract]
Ceded premiums payable
Reinsurance Payable
Reinsurance Payable
Less:
Discounted Other Subrogation Before Reinsurance [Abstract]
Discounted other subrogation, before reinsurance.
Trading Arrangements, by Individual
Trading Arrangements, by Individual [Table]
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), OCI
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), OCI
Level 3 [Member]
Fair Value, Inputs, Level 3 [Member]
Fair Value, Inputs, Level 3 [Member]
Balance at beginning
Balance at end
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held
Treasury Stock, Common, Shares
Treasury Stock, Common, Shares
International Finance [Member]
International Finance [Member]
International Finance [Member]
Debt Securities, Available-for-Sale, Excluding Accrued Interest
Debt Securities, Available-for-Sale, Excluding Accrued Interest
Amortized Cost, Due after five years through ten years
Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10
Non-PEO NEO Average Compensation Actually Paid Amount
Non-PEO NEO Average Compensation Actually Paid Amount
Future premiums expected to be collected, September 30, 2021
Financial Guarantee Insurance Contract, Premium Receivable, to be Collected, Third Quarter
High Yield Fund
High Yield Fund [Member]
High Yield Fund
Long-term debt
Long-term debt, Estimated fair value
Long-Term Debt, Fair Value
Net income (loss) attributable to common stockholders
Net income attributable to common shareholders
Net Income (Loss) Attributable to Parent
Loss and Loss Reserves [Axis]
Loss and Loss Reserves [Axis]
Loss and Loss Reserves [Axis]
Business Combination, Total Consideration
Business Combination, Total Consideration
Business Combination, Total Consideration
Derivative Contract [Domain]
Derivative Contract [Domain]
Summary of Notional Amounts of AFS's Trading Derivative Products
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]
Foreign Currency Transactions and Translations Policy [Policy Text Block]
Foreign Currency Transactions and Translations Policy [Policy Text Block]
Changed Peer Group, Footnote
Changed Peer Group, Footnote [Text Block]
Company Selected Measure Name
Company Selected Measure Name
Gross undiscounted claim liability
Schedule Of Insured Financial Obligations With Credit Deterioration Gross Undiscounted Claim Liability
This element represents the gross undiscounted claim liability for financial guarantee insurance contracts presented in the context of each surveillance grouping or category used by management to monitor and track potential deterioration in the credit worthiness of the insured party's ability to meet its financial obligations related to the contracts underlying financial guarantee insurance contracts the entity has issued.
Amortized Cost, Due after one year through five years
Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five
Securities acquired (transferred) in transactions related to Puerto Rico restructurings
Securities acquired (transferred) in transactions related to Puerto Rico restructurings
Securities acquired (transferred) in transactions related to Puerto Rico restructurings
Deferred Policy Acquisition Cost
Deferred Policy Acquisition Cost
General Reinsurance Company
General Reinsurance Company [Member]
General Reinsurance Company
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets [Line Items]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax
Income (Loss) from Continuing Operations before Income Taxes, Domestic
Income (Loss) from Continuing Operations before Income Taxes, Domestic
Major Jurisdictions
Summary of Income Tax Examinations [Table Text Block]
Name
Measure Name
Name
Forgone Recovery, Individual Name
Goodwill
Goodwill
Measurement Basis [Axis]
Measurement Basis [Axis]
Underlying Securities
Award Underlying Securities Amount
Claim and loss expense (payments) recoveries, net of subrogation and reinsurance
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Prior Years
Comprehensive Income
Comprehensive Income (Loss) Note [Text Block]
Fair Value Measurement [Domain]
Fair Value Measurement [Domain]
Gain (loss) on foreign currency translation, taxes
OCI, Foreign Currency Transaction and Translation Gain (Loss), Arising During Period, Tax
Collateral [Axis]
Collateral Held [Axis]
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax
OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax
Warrants [Member]
Warrant [Member]
Investment [Line Items]
Net Investment Income [Line Items]
Summary of Amortized Cost and Estimated Fair Value of Available-for-Sale Investments, Excluding VIE Investments Held by Successor Ambac, by Contractual Maturity
Investments Classified by Contractual Maturity Date [Table Text Block]
Business Combination, FX Forward Rate Lock
Business Combination, FX Forward Rate Lock
Business Combination, FX Forward Rate Lock
Fair Value Measurement Inputs and Valuation Techniques [Table]
Fair Value Measurement Inputs and Valuation Techniques [Table]
Debt Instrument, Name [Domain]
Debt Instrument, Name [Domain]
QBE Insurance Corporation
QBE Insurance Corporation [Member]
QBE Insurance Corporation
Reclassification out of Accumulated Other Comprehensive Income [Axis]
Reclassification out of Accumulated Other Comprehensive Income [Axis]
Financial assets:
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Income Statement Location [Axis]
Income Statement Location [Axis]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items]
Asset Pledged as Collateral [Member]
Asset Pledged as Collateral [Member]
Effect of potential dilutive shares
Weighted Average Number Diluted Shares Outstanding Adjustment
Weighted Average Number of Shares Outstanding, Diluted, Adjustment
Pledged Status [Axis]
Pledged Status [Axis]
Debt Securities, Available for sale, Unrealized Loss Position, Accumulated Loss, Including Pledged Securities
Debt Securities, Available for sale, Unrealized Loss Position, Accumulated Loss, Including Pledged Securities
Debt Securities, Available for sale, Unrealized Loss Position, Accumulated Loss, Including Pledged Securities
Summary of Carrying Amount and Fair Value of Ambac's Financial Assets and Liabilities
Fair Value, by Balance Sheet Grouping [Table Text Block]
Product and Service [Domain]
Product and Service [Domain]
Commercial Mortgage Backed Securities [Member]
Commercial Mortgage-Backed Securities [Member]
Other Performance Measure, Amount
Other Performance Measure, Amount
Beginning balance of net loss and loss expense reserves
Liability for Unpaid Claims and Claims Adjustment Expense, Net
Liability for Unpaid Claims and Claims Adjustment Expense, Net
Derivative, Collateral, Right to Reclaim Cash
Value of right to reclaim cash collateral and posted margin, recorded in Other assets
Derivative Liability, Subject to Master Netting Arrangement, Collateral, Right to Reclaim Cash Not Offset
Net Cash Provided by (Used in) Investing Activities [Abstract]
Net Cash Provided by (Used in) Investing Activities [Abstract]
Specialty Property & Casualty Program
Specialty Property & Casualty Program [Member]
Specialty Property & Casualty Program
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Securities Financing Transaction [Axis]
Securities Financing Transaction [Axis]
Credit Derivatives Contract Type [Axis]
Credit Derivatives Contract Type [Axis]
Future expected premiums to be earned, net of reinsurance, December 31, 2021
Financial Guarantee Insurance Contract, Premium Revenue to be Recognized, Fourth Quarter
Interest Expense
Interest Expense
Net realized gains on extinguishment of debt
Net realized gains on extinguishment of debt
Gain (Loss) on Extinguishment of Debt
Fixed Income Securities [Member]
Fixed Income Securities [Member]
Standard & Poor's, B- Rating [Member]
Standard & Poor's, B- Rating [Member]
Trading Arrangement:
Trading Arrangement [Axis]
Contract with Customer, Performance Obligation Satisfied in Previous Period
Contract with Customer, Performance Obligation Satisfied in Previous Period
Long-term Debt, Type [Domain]
Long-Term Debt, Type [Domain]
Entity File Number
Entity File Number
Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Debt Securities, Trading, and Equity Securities, FV-NI [Table]
Debt Securities, Trading, and Equity Securities, FV-NI [Table]
Debt Securities, Available-for-sale, Allowance for Credit Loss
Debt Securities, Available-for-Sale, Allowance for Credit Loss
Accumulated Gain (Loss), Financial Liability, Fair Value Option, Attributable to Parent [Member]
Accumulated Gain (Loss), Financial Liability, Fair Value Option, Attributable to Parent [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Intangible amortization
Amortization of Intangible Assets
Amortization of Intangible Assets
Entity Shell Company
Entity Shell Company
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value
Business Acquisition, Acquiree [Domain]
Business Acquisition, Acquiree [Domain]
Plus: Loss adjustment expenses reserves
Schedule Of Insured Financial Obligations With Credit Deterioration Loss Adjustment Expenses Reserve
This element represents the amount of loss adjustment expense reserves represent the costs estimated to be incurred in the settlement of unpaid claims related to financial guarantee insurance contracts and presented in the schedule of insured financial obligations with credit deterioration in the context of each surveillance grouping or category used by management to monitor and track potential deterioration in the credit worthiness of the insured party's ability to meet its financial obligations related to the contracts underlying financial guarantee insurance contracts the entity has issued.
DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss, including pledged securities
DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss, including pledged securities
DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss, including pledged securities
Restatement Determination Date
Restatement Determination Date
Student Loans [Member]
Student Loans [Member]
Student Loans [Member]
V [Member]
Surveillance Category Five [Member]
Surveillance category five.
Rule 10b5-1 Arrangement Adopted
Rule 10b5-1 Arrangement Adopted [Flag]
Claim liability reported on Balance Sheet, before reinsurance
Claim liability reported on Balance Sheet, before reinsurance
Schedule of Insured Financial Obligations with Credit Deterioration, Statement of Financial Position, Claim Liability
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Cash, cash equivalents, and restricted cash at beginning of period
Cash, cash equivalents, and restricted cash at end of period
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents
Asset Class [Axis]
Asset Class [Axis]
Other adjustments (including foreign exchange)
Financial Guarantee Insurance Contracts, Premiums Receivable, Increase (Decrease), Other Adjustments
Business Disposal, Cash Expected to be Received
Business Disposal, Cash Expected to be Received
Business Disposal, Cash Expected to be Received
Premium receivables
Increase (Decrease) in Premiums Receivable
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer
Common stock, shares issued
Common Stock, Shares, Issued
Gross insured contractual payments outstanding:
Schedule of Insured Financial Obligations with Credit Deterioration, Insured Contractual Payments Outstanding [Abstract]
Total financial assets
Assets, Fair Value Disclosure
Long-term debt
Long-term Debt
Long-Term Debt
Reinsurance Recoverable, Credit Quality Indicator
Reinsurance Recoverable, Credit Quality Indicator [Table Text Block]
Future expected premiums to be earned, net of reinsurance, December 31, 2035
Financial Guarantee Insurance Contract, Premium Revenue to be Recognized, after Year 10 Through 15
Net Income Loss Reconciliation [Line Items]
Net Income Loss Reconciliation [Line Items]
Net Income Loss Reconciliation [Line Items]
Premiums Receivable by Risk Classification Code [Table Text Block]
Premiums Receivable by Risk Classification Code [Table Text Block]
Premiums Receivable by Risk Classification Code [Table Text Block]
Accumulated Translation Adjustment [Member]
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Noncontrolling Interest Disclosure
Noncontrolling Interest Disclosure [Text Block]
Other Consumer Asset-Backed [Member]
Other Consumer Asset Backed [Member]
Other consumer asset-backed.
Total comprehensive income (loss) attributable to common stockholders
Total comprehensive income (loss)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
External Credit Rating, Standard & Poor's [Domain]
External Credit Rating, Standard & Poor's [Domain]
Summary of Rollforward of RMBS Subrogation, by Estimation Approach
Summary Of Balance Of Rmbs Subrogation Recoveries By Estimation Approach Table [Text Block]
Tabular presentation of rollforward of RMBS subrogation, by estimation approach.
Domestic Tax Authority [Member]
Domestic Tax Authority [Member]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities
Interest Paid, Including Capitalized Interest, Operating and Investing Activities
Entity Address, Address Line One
Entity Address, Address Line One
Equity Securities Excluded From Fair Value
Equity Securities Excluded From Fair Value [Member]
Equity Securities Excluded From Fair Value
Financial liabilities:
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Equity investments in pooled funds [Member]
Equity investments in pooled funds [Member]
Equity investments in pooled funds [Member]
Foreign Exchange Future
Foreign Exchange Future [Member]
Schedule of Cash Flow Supplemental Information [Axis]
Schedule of Cash Flow Supplemental Information [Axis]
Schedule of Cash Flow Supplemental Information [Axis]
Proceeds from Insurance Premiums Collected
Proceeds from Insurance Premiums Collected
Other Public Finance Sectors [Member]
Other Public Finance Sectors [Member]
Other Public Finance Sectors [Member]
Proceeds from paydowns of consolidated VIE assets
Proceeds From Financial Guaranty Variable Interest Entity Assets
Proceeds From Financial Guaranty Variable Interest Entity Assets
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Other Comprehensive Income Loss
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Other Comprehensive Income Loss
Amount of gain or loss included in other comprehensive income arising from financial instruments measured on a recurring basis using unobservable inputs.
Subsequent Event
Subsequent Event [Member]
Gross other subrogation
Schedule Of Insured Financial Obligations With Credit Deterioration Reductions Of Gross Undiscounted Claim Liability Gross Undiscounted Other Subrogation
This element represents the reduction to gross undiscounted claim liability for gross undiscounted subrogation on insured financial obligations with credit deterioration, excluding subrogation on insured RMBS financial obligations with credit deterioration.
NOL allocated amount
Operating Loss Carryforwards
Net Income (Loss) Attributable to Redeemable Noncontrolling Interest
Net Income (Loss) Attributable to Redeemable Noncontrolling Interest
Schedule of Finite-Lived Intangible Assets
Schedule of Finite-Lived Intangible Assets [Table Text Block]
Effects of Reinsurance [Table]
Effects of Reinsurance [Table]
Income Statement [Abstract]
Income Statement [Abstract]
Schedule of Investments [Line Items]
Investment [Line Items]
Schedule of Investments [Line Items]
Insider Trading Policies and Procedures Adopted
Insider Trading Policies and Procedures Adopted [Flag]
Cash
Cash and Cash Equivalents, Fair Value Disclosure
External Credit Rating by Grouping [Axis]
External Credit Rating by Grouping [Axis]
Percentage of investment portfolio valued using internal valuation models
Percentage Of Investment Portfolio Valued Using Internal Valuation Models
Percentage of investment portfolio valued using internal valuation models.
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Period Increase (Decrease)
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Period Increase (Decrease)
Derivative Liability
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities
Derivative Liability
Summary of Gains and Losses (Realized and Unrealized) Relating to Level 3 Assets and Liabilities Included in Earnings
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Table Text Block]
Tax Credit Carryforward [Line Items]
Tax Credit Carryforward [Line Items]
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture
Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture
Summary of Loss Reserve Roll-Forward, Net of Subrogation Recoverable and Reinsurance
Schedule of Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block]
Other Commitments [Domain]
Other Commitments [Domain]
Proceeds from (Payments to) Noncontrolling Interests
Proceeds from (Payments to) Noncontrolling Interests
Other Investments [Member]
Other Investments [Member]
Financial Instrument [Axis]
Financial Instrument [Axis]
Total gains or losses included in earnings for the period
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings
Net liability fair value of all derivative instruments linked to Ambac's own credit risk
Derivative, Net Liability Position, Aggregate Fair Value
Total Shareholder Return Amount
Total Shareholder Return Amount
Entity Common Stock, Shares Outstanding
Entity Common Stock, Shares Outstanding
Adjustment To PEO Compensation, Footnote
Adjustment To PEO Compensation, Footnote [Text Block]
Deferred Foreign Income Tax Expense (Benefit)
Deferred Foreign Income Tax Expense (Benefit)
Fixed Income Funds
Fixed Income Funds [Member]
Segments [Domain]
Segments [Domain]
Fair Value Hierarchy and NAV [Axis]
Fair Value Hierarchy and NAV [Axis]
Securities fair value
Fair Value Of Securities Deposited With Governmental Authorities
Fair Value Of Securities Deposited With Governmental Authorities
Fair value of securities deposited with governmental authorities.
Consolidation Items [Domain]
Consolidation Items [Domain]
Schedule of Other than Temporary Impairment, Credit Losses Recognized in Earnings [Table]
Schedule of Other than Temporary Impairment, Credit Losses Recognized in Earnings [Table]
Schedule of Cash Flow Supplemental Information [Domain]
Schedule of Cash Flow Supplemental Information [Domain]
[Domain] for Schedule of Cash Flow Supplemental Information [Axis]
Revenue Recognition and Deferred Revenue [Abstract]
Retained earnings
Retained Earnings (Accumulated Deficit)
Collateral [Domain]
Collateral Held [Domain]
Prior Year Claims and Claims Adjustment Expense
Prior Year Claims and Claims Adjustment Expense
Entity Address, State or Province
Entity Address, State or Province
Compensation Actually Paid vs. Total Shareholder Return
Compensation Actually Paid vs. Total Shareholder Return [Text Block]
Cash collateral payable
Cash collateral payable
Cash collateral payable
Cash flows from operating activities:
Net Cash Provided by (Used in) Operating Activities [Abstract]
Residential Mortgage-Backed Securities [Member]
Residential Mortgage-Backed Securities [Member]
Accrued interest payable
Increase (Decrease) in Interest Payable, Net
Proceeds from matured bonds
Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale
Noncontrolling Interest, Change in Redemption Value
Noncontrolling Interest, Change in Redemption Value
Gain (Loss) on Investments [Member]
Gain (Loss) on Investments [Member]
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest
Total before tax
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest
Standard & Poor's, AA Rating
Standard & Poor's, AA Rating [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Business Disposal, Potential Out Of Pocket Expense Reimbursement
Business Disposal, Potential Out Of Pocket Expense Reimbursement
Business Disposal, Potential Out Of Pocket Expense Reimbursement
Asset Class [Domain]
Asset Class [Domain]
Derivative assets
Derivative Asset, Fair Value, Gross Asset
Derivative Asset, Subject to Master Netting Arrangement, before Offset
Equity Securities Excluded From Fair Value Table
Equity Securities Excluded From Fair Value
Equity Securities Excluded From Fair Value
Class of Stock [Domain]
Class of Stock [Domain]
Net of tax and noncontrolling interest
Net Income (Loss) Available to Common Stockholders, Basic
Net Income (Loss) Available to Common Stockholders, Basic
Schedule of Amounts Reclassed Out of Each Component of Accumulated Other Comprehensive Income
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]
Credit Rating, Moody's [Axis]
Credit Rating, Moody's [Axis]
Components of Loss and Loss Expense Reserves and Subrogation Recoverable [Line Items]
Components of Loss and Loss Expense Reserves and Subrogation Recoverable [Line Items]
[Line Items] for Components of Loss and Loss Expense Reserves and Subrogation Recoverable [Table]
Investment Owned, at Fair Value
Fair value of securities that include benefit of guarantees provided by financial guarantors
Investment Owned, Fair Value
Organization, Consolidation and Presentation of Financial Statements Disclosure
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]
Total Shareholder Return Vs Peer Group
Total Shareholder Return Vs Peer Group [Text Block]
Unsecured Reinsurance Recoverable, All Other
Unsecured Reinsurance Recoverable, All Other
Unsecured Reinsurance Recoverable, All Other
AOCI Attributable to Parent [Member]
Retained Earnings [Member]
AOCI Attributable to Parent [Member]
Aggregate Erroneous Compensation Amount
Aggregate Erroneous Compensation Amount
Reinsurance Recoverable Credit Exposure
Reinsurance Recoverable Credit Exposure
Reinsurance Recoverable Credit Exposure
Type and Tier Identifier [Domain]
Type and Tier Identifier [Domain]
All Executive Categories
All Executive Categories [Member]
Ambac Insured Securities
Ambac Insured Securities [Member]
Ambac Insured Securities
Commitments [Member]
Commitments [Member]
Derivative Liability, Fair Value, Amount Offset Against Collateral
Derivative Liability, Including Not Subject to Master Netting Arrangement, after Offset and Deduction
Less: comprehensive (gain) loss attributable to the noncontrolling interest
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest [Abstract]
Accumulated Other Comprehensive Income (Loss) [Table]
Accumulated Other Comprehensive Income (Loss) [Table]
Financial Guarantee
Financial Guarantee [Member]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Settlements
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Settlements
Amount of settlements related to financial instruments measured on a recurring basis using unobservable inputs.
Premiums Receivable, Gross
Premiums Receivable, Gross
Standard & Poor's, B Rating [Member]
Standard & Poor's, B Rating [Member]
Debt Disclosure [Abstract]
Premium Receivable, Credit Loss Expense (Reversal)
Premium Receivable, Credit Loss Expense (Reversal)
Number of Reportable Segments
Number of Reportable Segments
Percentage of investment portfolio valued using dealer quotes
Percentage Of Investment Portfolio Valued Using Dealer Quotes
Investment portfolio valued using dealer quotes.
Earnings Per Share [Abstract]
Earnings Per Share [Abstract]
Common Stock, Value, Issued
Common Stock, Value, Issued
Insurance [Table]
Insurance [Table]
Insurance [Table]
Estimated Fair Value, Due after one year through five years
Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five
Fair Value Measured at Net Asset Value Per Share [Member]
Fair Value Measured at Net Asset Value Per Share [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Insurance Liabilities
Variable Interest Entity Nonconsolidated Carrying Amount Insurance Liabilities
The carrying amount of insurance liabilities in the reporting entity's statement of financial position that relate to the entity's variable interests in Variable Interest Entities (VIEs) where the VIEs are not consolidated.
Fair value of posted assets as collateral
Collateral Already Posted, Aggregate Fair Value
Income Loss On Variable Interest Entities [Member]
Income Loss On Variable Interest Entities [Member]
Income (loss) on variable interest entities.
Accrued interest payable
Interest Payable
Interest Payable
Standard & Poor's, A Rating
Standard & Poor's, A Rating [Member]
Restricted Cash
Restricted Cash
All Individuals
All Individuals [Member]
Estimated Fair Value due, Total
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Fair Value
Equity Funds
Equity Funds [Member]
Entity Filer Category
Entity Filer Category
Schedule of Equity Method Investments [Line Items]
Schedule of Equity Method Investments [Line Items]
Non-PEO NEO Average Total Compensation Amount
Non-PEO NEO Average Total Compensation Amount
Statement [Table]
Statement [Table]
Current Fiscal Year End Date
Current Fiscal Year End Date
Interest Expense, Long-term Debt
Interest Expense, Long-Term Debt
Income Tax Authority [Axis]
Income Tax Authority [Axis]
PEO Name
PEO Name
Other Sundry Liabilities, Current
Other Sundry Liabilities, Current
Number of policies
Schedule of Insured Financial Obligations with Credit Deterioration, Number of Contracts Issued and Outstanding
Preferred stock, shares authorized
Preferred Stock, Shares Authorized
Variable interest entity assets:
Variable Interest Entity Classification Of Carrying Amount Assets [Abstract]
Variable Interest Entity Classification Of Carrying Amount Assets [Abstract]
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Business Combination, Number of Shares Issued for Beat Acquisition
Business Combination, Number of Shares Issued for Beat Acquisition
Business Combination, Number of Shares Issued for Beat Acquisition
Schedule of Goodwill
Schedule of Goodwill [Table Text Block]
Illiquid Investments [Member]
Illiquid Investments [Member]
Illiquid Investments [Member]
Deferred ceded premium
Prepaid Reinsurance Premiums
Other Income or (Loss) [Member]
Other Income [Member]
Other Income [Member]
Debt Securities, Available-for-Sale, Current
Debt Securities, Available-for-Sale, Current
Purchases of other invested assets
Payments to Acquire Other Investments
Premiums Written, Net
Premiums written, net of reinsurance
Premiums Written, Net
Investment Portfolio [Member]
Investment Portfolio [Member]
Investment portfolio.
Other, net
Increase (Decrease) in Other Operating Assets and Liabilities, Net
Total
Schedule of Insured Financial Obligations with Credit Deterioration, Insured Contractual Payments Outstanding
Euro Member Countries, Euro
Euro Member Countries, Euro
Statement of Financial Position [Abstract]
Statement of Financial Position [Abstract]
Total Ambac Financial Group, Inc. stockholders’ equity
Equity, Attributable to Parent
Business Combination, Credit Facility Cash Used for Beat Acquisition
Business Combination, Credit Facility Cash Used for Beat Acquisition
Business Combination, Credit Facility Cash Used for Beat Acquisition
Payments of consolidated VIE liabilities, net
Paydown of Financial Guaranty Variable Interest Entity Liabilities
Paydown of Financial Guaranty Variable Interest Entity Liabilities
Policyholder Benefits and Claims Incurred, Net
Policyholder Benefits and Claims Incurred, Net
Schedule of Finite-Lived Intangible Assets [Table]
Schedule of Finite-Lived Intangible Assets [Table]
Business Combination, Potential Late Closing Penalty Per Day
Business Combination, Potential Late Closing Penalty Per Day
Business Combination, Potential Late Closing Penalty Per Day
Premiums Earned, Net
Premiums Earned, Net
Weighted average risk-free rate used to discount loss reserves
Financial Guarantee Insurance Contracts, Claim Liability, Weighted Average Risk Free Discount Rate
Reporting Unit [Axis]
Reporting Unit [Axis]
Finite-Lived Intangible Assets, Major Class Name [Domain]
Finite-Lived Intangible Assets, Major Class Name [Domain]
Restatement [Domain]
Revision of Prior Period [Domain]
Derivative, Gain (Loss) on Derivatives, Total Net
Derivative, Gain (Loss) on Derivatives, Total Net
Derivative, Gain (Loss) on Derivatives, Total Net
Change in short-term investments
Payments for (Proceeds from) Short-Term Investments
Net realized (losses) gains
Debt Securities, Available-for-Sale, Realized Gain (Loss), Excluding Other-than-temporary Impairment
Fiduciary Funds Held by Insurance Distribution Subsidiaries
Fiduciary Funds Held by Insurance Distribution Subsidiaries
Fiduciary Funds Held by Insurance Distribution Subsidiaries
Level 2 [Member]
Fair Value, Inputs, Level 2 [Member]
Current Year Claims and Claims Adjustment Expense
Current Year Claims and Claims Adjustment Expense
Credit Rating, Standard & Poor's [Axis]
Credit Rating Source [Axis]
Credit Rating, Standard & Poor's [Axis]
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax
Prior service cost
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Named Executive Officers, Footnote
Named Executive Officers, Footnote [Text Block]
Document Fiscal Period Focus
Document Fiscal Period Focus
Loans Receivable [Member]
Loans Receivable [Member]
Reinsurance recoveries of losses included in losses and loss expenses
Policyholder Benefits and Claims Incurred, Ceded
Policyholder Benefits and Claims Incurred, Ceded
Policyholder Benefits and Claims Incurred, Ceded
Fair Value Inputs Yield
Yield
Fair Value Inputs Yield
Fair value inputs yield.
Share-based compensation
Share-Based Payment Arrangement, Noncash Expense
Future expected premiums to be earned, net of reinsurance, June 30, 2021
Financial Guarantee Insurance Contract, Premium Revenue to be Recognized, Second Quarter
City Area Code
City Area Code
Product and Service [Axis]
Product and Service [Axis]
Interest
Schedule of Insured Financial Obligations with Credit Deterioration, Insured Contractual Payments Outstanding, Interest
Net Income Per Share
Earnings Per Share [Text Block]
Long-term Debt, at par less amortized discount
Long-term Debt, at par less amortized discount
Long-term Debt, at par less amortized discount
Liability for Claim and Claim Adjustment Expenses Net of Subrogation recoverables
Liability for Claim and Claim Adjustment Expenses Net of Subrogation recoverables
Liability for Claim and Claim Adjustment Expenses Net of Subrogation recoverables
Document Fiscal Year Focus
Document Fiscal Year Focus
Geographical [Domain]
Geographical [Domain]
Financial Guarantee Insurance Contracts, Premium Receivable
Beginning premium receivable
Ending premium receivable
Financial Guarantee Insurance Contracts, Premium Receivable
Financial Guarantee Insurance Contracts, Premium Received over Contract Period
Financial Guarantee Insurance Contracts, Premium Received over Contract Period [Table Text Block]
Insurance Distribution
Insurance Distribution [Member]
Insurance Distribution
Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]
Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]
Exercise Price
Award Exercise Price
Finite-Lived Intangible Assets by Major Class [Axis]
Finite-Lived Intangible Assets by Major Class [Axis]
Goodwill and Intangible Assets Disclosure [Abstract]
Total financial liabilities
Liabilities, Fair Value Disclosure
Underlying Asset Class [Axis]
Underlying Asset Class [Axis]
Commercial Auto
Commercial Auto [Member]
Commercial Auto
Product and Service, Other
Product and Service, Other [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Total
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest
Future expected premiums to be earned, net of reinsurance, December 31, 2055
Financial Guarantee Insurance Contract, Premium Revenue to be Recognized, after Year 30 Through 35
Amortization of bond premium and discount
Accretion (Amortization) of Discounts and Premiums, Investments
Total liabilities and stockholders’ equity
Liabilities and Equity
Debt Securities, Available-for-sale, Amortized Cost
Debt Securities, Available-for-sale, Amortized Cost
Debt Securities, Available-for-Sale, Amortized Cost
Peer Group Total Shareholder Return Amount
Peer Group Total Shareholder Return Amount
Equity Valuation Assumption Difference, Footnote
Equity Valuation Assumption Difference, Footnote [Text Block]
Current Foreign Tax Expense (Benefit)
Current Foreign Tax Expense (Benefit)
Collateral Pledged [Member]
Collateral Pledged [Member]
Currency [Axis]
Currency [Axis]
Other than Temporary Impairment Losses, Investments
Other than Temporary Impairment Losses, Investments
Surveillance Category [Domain]
Surveillance Category [Domain]
Arrangement Duration
Trading Arrangement Duration
Investment expense
Investment Income, Investment Expense
Fixed Income Investments And Other Investments [Member]
Fixed Income Investments And Other Investments [Member]
Fixed income investments and other investments Member.
Entity Address, City or Town
Entity Address, City or Town
Award Timing MNPI Considered
Award Timing MNPI Considered [Flag]
Schedule Of Earnings Per Share [Table]
Schedule Of Earnings Per Share [Table]
Schedule Of Earnings Per Share [Table]
Schedule of Segment Reporting Information, by Segment
Schedule of Segment Reporting Information, by Segment [Table Text Block]
Future expected premiums to be earned, net of reinsurance, December 31, 2022
Financial Guarantee Insurance Contract, Premium Revenue to be Recognized, Year Two
Termination Date
Trading Arrangement Termination Date
Estimated Future Premium Payments Minimum Discounted Rate
Estimated Future Premium Payments Minimum Discounted Rate
Estimated Future Premium Payments Minimum Discounted Rate
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis Asset or Liability, Transfers into or out of Level 3
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis Asset or Liability, Transfers into or out of Level 3
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis Asset or Liability, Transfers into or out of Level 3
Adjustments for Change in Accounting Principle [Domain]
Change in Accounting Principle, Type [Domain]
Common stock, shares authorized
Common Stock, Shares Authorized
Fixed maturity securities, at fair value
Debt Securities, Available-for-Sale
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability
Fair value measurement with unobservable inputs reconciliation recurring basis asset or liability.
Summary of Carrying Amount of Assets, Liabilities and Maximum Exposure to Loss of Ambac's Variable Interests in Non-Consolidated Variable Interest Entities
Variable Interest Entity Not Primary Beneficiary Table [Text Block]
Tabular presentation of the carrying amounts of assets and liabilities in the reporting entity's statement of financial position that relate to the reporting entity's variable interests in non-consolidated variable interest entities (VIEs) resulting from financial guarantee and credit derivative contracts, and the maximum exposure to loss as a result of its involvement with such VIEs.
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax
Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax
Short-term Investments [Member]
Short-Term [Member]
Short-Term Investments [Member]
Underlying Asset Class [Domain]
Underlying Asset Class [Domain]
Adjustments to reconcile net income to net cash used in operating activities:
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Net Amount, Derivative Assets
Derivative Assets Net Amount
Derivative Assets Net Amount
Derivative [Line Items]
Derivative [Line Items]
Award Timing Disclosures [Line Items]
Reinsurance, Reinsured Risk, Percentage
Reinsurance, Reinsured Risk, Percentage
Variable Interest Entity, Measure of Activity, Income or Loss before Tax
Variable Interest Entity, Measure of Activity, Income or Loss before Tax
Premium Receivable, Allowance for Credit Loss, Recovery
Premium Receivable, Allowance for Credit Loss, Recovery
Other Commitments [Axis]
Other Commitments [Axis]
Additional paid-in capital
Additional Paid in Capital
Estimated Fair Value, Due after five years through ten years
Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10
Nonredeemable Noncontrolling Interest
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest
Loans
Loans, Estimated fair value
Loans Receivable, Fair Value Disclosure
Adjustments for changes in expected and contractual cash flows
Financial Guarantee Insurance Contracts, Premiums Receivable, Increase (Decrease), Change in Period of Contract
Pledged Status [Domain]
Pledged Status [Domain]
Derivative Financial Instruments, Liabilities [Member]
Derivative Financial Instruments, Liabilities [Member]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Purchases
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Purchases
Amount of purchases of financial instruments measured on a recurring basis using unobservable inputs.
Fair value of derivative liabilities
Derivative Liability, Fair Value, Amount Not Offset Against Collateral
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral
Future premiums expected to be collected, December 31, 2050
Financial Guarantee Insurance Contract, Premium Receivable, to be Collected, after Year 25 Through 30
Municipal Bonds [Member]
Municipal Bonds [Member]
Insider Trading Arrangements [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Deconsolidation Of Vies
Fair value of financial instruments measured on a recurring basis using unobservable inputs removed as a result of the deconsolidation of variable interest entities.
Number of new common stock issued
Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture
Entity Registrant Name
Entity Registrant Name
Material Terms of Trading Arrangement
Material Terms of Trading Arrangement [Text Block]
Award Timing Method
Award Timing Method [Text Block]
Adjustment to Compensation, Amount
Adjustment to Compensation Amount
Investments:
Net Assets
Noncontrolling interest
Stockholders' Equity Attributable to Noncontrolling Interest
Equity, Attributable to Noncontrolling Interest
Compensation Actually Paid vs. Net Income
Compensation Actually Paid vs. Net Income [Text Block]
Peer Group Issuers, Footnote
Peer Group Issuers, Footnote [Text Block]
Future premiums expected to be collected, December 31, 2030
Financial Guarantee Insurance Contract, Premium Receivable, to be Collected, after Year 5 Through 10
Reconciliation of Revenue from Segments to Consolidated [Table]
Reconciliation of Revenue from Segments to Consolidated [Table]
Corporate and Other
Corporate and Other [Member]
Entity Central Index Key
Entity Central Index Key
Derivative, Gain (Loss) on Derivative, Net
Gains in change in fair value of the call options
Derivative, Gain (Loss) on Derivative, Net
Total gains or losses included in earnings for the period
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings
Long-term Debt [Member]
Long-term Debt [Member]
Long-Term Debt [Member]
Stock-based compensation
Share-Based Payment Arrangement, Expense
Non-Rule 10b5-1 Arrangement Terminated
Non-Rule 10b5-1 Arrangement Terminated [Flag]
Income Tax Authority [Domain]
Income Tax Authority [Domain]
Losses and loss expenses, net
Increase (Decrease) in Liability for Claims and Claims Adjustment Expense Reserve
Name
Trading Arrangement, Individual Name
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent
Net gains (losses) on derivative contracts [Domain]
Net gains (losses) on derivative contracts [Domain]
Net gains (losses) on derivative contracts [Domain]
Disaggregation of Revenue
Disaggregation of Revenue [Table Text Block]
Employee Stop Loss Time When Base Commissions Recognized Begin and End In Months
Employee Stop Loss Time When Base Commissions Recognized Begin and End In Months
Employee Stop Loss Time When Base Commissions Recognized Begin and End In Months
Debt Securities, Available-for-sale, Allowance for Credit Loss, Not to Sell before Recovery, Credit Loss, Previously Recorded, Expense (Reversal)
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Not to Sell before Recovery, Credit Loss, Previously Recorded, Expense (Reversal)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax
Actuarial gains (losses)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax
Revenue from Contract with Customer, Excluding Assessed Tax
Revenue from Contract with Customer, Excluding Assessed Tax
Entity [Domain]
Entity [Domain]
Long-term Debt, Type [Axis]
Long-Term Debt, Type [Axis]
Amendment Flag
Amendment Flag
Legal Entity [Axis]
Legal Entity [Axis]
Gain (loss) from consolidating VIEs
Variable Interest Entity, Initial Consolidation, Gain (Loss)
Future expected premiums to be earned, net of reinsurance, December 31, 2024
Financial Guarantee Insurance Contract, Premium Revenue to be Recognized, Year Four
Estimated Fair Value, Due in one year or less
Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Schedule of Variable Interest Entities Assets and Liabilities [Table Text Block]
Schedule of Variable Interest Entities Assets and Liabilities [Table Text Block]
Schedule of Variable Interest Entities Assets and Liabilities [Table Text Block]
Summary of Amounts Included in Net Realized (Losses) Gains and Other-Than-Temporary Impairments
Gain (Loss) on Securities [Table Text Block]
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), after Tax
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), after Tax
Weighted Average Number of Shares Outstanding, Diluted
Weighted average number of common shares and potential dilutive shares used for diluted earnings per share
Weighted Average Number of Shares Outstanding, Diluted
Affinity Products
Affinity Products [Member]
Affinity Products
Forgone Recovery, Explanation of Impracticability
Forgone Recovery, Explanation of Impracticability [Text Block]
Deferred Policy Acquisition Costs, Amortization Expense
Deferred Policy Acquisition Costs, Amortization Expense
Entity Incorporation, Date of Incorporation
Entity Incorporation, Date of Incorporation
Expenses:
Operating Expenses [Abstract]
Net Income Loss Reconciliation [Table]
Net Income Loss Reconciliation [Table]
Net Income Loss Reconciliation [Table]
Fair Value of Cash and Securities Pledged to Derivative Counterparties
Fair Value Of Cash And Securities Pledged To Derivative Counterparties
Fair value of cash and securities pledged to derivative counterparties.
Debt Securities, Available-for-sale, Realized Loss
Available-for-sale Securities, Gross Realized Losses
Debt Securities, Available-for-Sale, Realized Loss
Company Selected Measure Amount
Company Selected Measure Amount
Change in fair value of credit derivatives:
Credit Risk Derivatives, at Fair Value, Net [Abstract]
Parsed Fixed Income Securities
Parsed Fixed Income Securities [Member]
Parsed Fixed Income Securities
Total assets
Assets
Name
Awards Close in Time to MNPI Disclosures, Individual Name
Future expected premiums to be earned, net of reinsurance, December 31, 2025
Financial Guarantee Insurance Contract, Premium Revenue to be Recognized, Year Five
Business Combination, Potential Late Closing Penalty Maximum
Business Combination, Potential Late Closing Penalty Maximum
Business Combination, Potential Late Closing Penalty Maximum
Loss and Loss Reserves [Domain]
Loss and Loss Reserves [Domain]
[Domain] for Loss and Loss Reserves [Axis]
Future premiums expected to be collected, December 31, 2040
Financial Guarantee Insurance Contract, Premium Receivable, to be Collected, after Year 15 Through 20
Entity Bankruptcy Proceedings, Reporting Current
Entity Bankruptcy Proceedings, Reporting Current
Ceded Reinsurance Premiums Earned
Ceded Premiums Earned
Background And Basis Of Presentation [Table]
Background And Basis Of Presentation [Table]
Background And Basis Of Presentation [Table]
Effects of Reinsurance
Effects of Reinsurance [Table Text Block]
Non-NEOs
Non-NEOs [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Ambac Rating
Notional Disclosures [Abstract]
Less: Unearned premium reserves
Schedule of Insured Financial Obligations with Credit Deterioration, Statement of Financial Position, Unearned Premium Revenue
Pretax income (loss)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest
Net Cash Provided by (Used in) Financing Activities [Abstract]
Net Cash Provided by (Used in) Financing Activities [Abstract]
Gross Investment Income, Operating
Gross Investment Income, Operating
Non-PEO NEO
Non-PEO NEO [Member]
Adjustment to Compensation:
Adjustment to Compensation [Axis]
Contract with Customer, Asset, after Allowance for Credit Loss
Contract with Customer, Asset, after Allowance for Credit Loss
Scenario [Axis]
Scenario [Axis]
Weighted Average Number of Shares Outstanding, Basic
Weighted average number of common shares used for basic earnings per share
Weighted Average Number of Shares Outstanding, Basic
Financial Guarantee
Legacy Financial Guarantee [Member]
Legacy Financial Guarantee
Investment Contracts [Member]
Investment Contracts [Member]
Investment Contracts [Member]
Reclassifications
Reclassification, Comparability Adjustment [Policy Text Block]
Loan Origination Commitments [Member]
Loans [Member]
Loan Origination Commitments [Member]
Real Estate [Member]
Real Estate [Member]
Insurance Type and Tier Identifier [Axis]
Insurance Type and Tier Identifier [Axis]
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Revenues:
Revenues [Abstract]
Pay vs Performance Disclosure
Pay vs Performance Disclosure [Table]
Ceded Loss And Loss Expenses Paid Not Yet Recovered
Ceded Loss And Loss Expenses Paid Not Yet Recovered
Ceded Loss And Loss Expenses Paid Not Yet Recovered
Statement [Line Items]
Statement [Line Items]
Future premiums expected to be collected, December 31, 2023
Financial Guarantee Insurance Contract, Premium Receivable, to be Collected, Year Three
Foreign Exchange
Foreign Exchange [Member]
Debt Securities, Available-for-Sale
Debt Securities, Available-for-Sale [Table Text Block]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Earnings
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Earnings
Amount of gain or loss included in earnings arising from financial instruments measured on a recurring basis using unobservable inputs.
Summary of Investment Holdings [Table]
Summary of Investment Holdings [Table]
Reclassification out of Accumulated Other Comprehensive Income [Domain]
Reclassification out of Accumulated Other Comprehensive Income [Domain]
Noncontrolling Interest [Member]
Noncontrolling Interest [Member]
Tax Credit Carryforward [Axis]
Tax Credit Carryforward [Axis]
Insurance Assets
Variable Interest Entity Nonconsolidated Carrying Amount Insurance Assets
The carrying amount of insurance assets in the reporting entity's statement of financial position that relate to the entity's variable interests in Variable Interest Entities (VIEs) where the VIEs are not consolidated.