XML 81 R68.htm IDEA: XBRL DOCUMENT
v3.25.3

Insurance - Summary of Percentage Ceded to Reinsurers and Reinsurance Recoverable and Rating Levels (Details) - USD ($) $ in Thousands | Sep. 30, 2025 | Dec. 31, 2024 | Sep. 30, 2024
--- | --- | --- | ---
Summary of Ceded Par and Net Unsecured Reinsurance Recoverable [Line Items] |  |  |
Ceded Loss And Loss Expenses Paid Not Yet Recovered |  |  | $ 41,225
Reinsurance Recoverable, Allowance for Credit Loss | $ 100 | $ 100 |
Reinsurance Recoverables, Gross | 440,462 |  |
Unsecured Reinsurance Recoverables | 304,283 |  |
Reinsurance Recoverable, Gross, All Other | 175,331 |  |
Unsecured Reinsurance Recoverable, All Other | 98,083 |  |
Letters of Credit Outstanding, Amount | $ 72,454 |  |
Number of Reinsurers Covering Majority | 5 |  |
Percentage of Ceded Reinsurance Recoverable Represented by Top Three | 60.20% |  |
Uncollateralized Credit Exposure Supoorted by Unlimited Uncapped Indemnity | $ 28,999 | 35,146 |
Deferred Ceded Premiums And Reinsurance Recoverables | 601,368 |  |
Reinsurance Recoverable Credit Exposure | 304,283 | $ 232,310 |
QBE Insurance Corporation | Property and Casualty, Commercial Insurance | Standard & Poor's, A Rating |  |  |
Summary of Ceded Par and Net Unsecured Reinsurance Recoverable [Line Items] |  |  |
Reinsurance Recoverables, Gross | 27,255 |  |
Unsecured Reinsurance Recoverables | 27,255 |  |
Assured Guaranty Re Ltd | Financial Guarantee | Standard & Poor's, A+ Rating |  |  |
Summary of Ceded Par and Net Unsecured Reinsurance Recoverable [Line Items] |  |  |
Reinsurance Recoverables, Gross | 49,677 |  |
Unsecured Reinsurance Recoverables | 32,540 |  |
General Reinsurance Company | Property and Casualty, Commercial Insurance | Standard Poors A Plus Plus Rating |  |  |
Summary of Ceded Par and Net Unsecured Reinsurance Recoverable [Line Items] |  |  |
Reinsurance Recoverables, Gross | 148,776 |  |
Unsecured Reinsurance Recoverables | 130,515 |  |
Swiss Reinsurance America Corporation | Financial Guarantee | Standard & Poor's, A+ Rating |  |  |
Summary of Ceded Par and Net Unsecured Reinsurance Recoverable [Line Items] |  |  |
Reinsurance Recoverables, Gross | 17,486 |  |
Unsecured Reinsurance Recoverables | 15,890 |  |
Swiss Reinsurance America Corporation | Financial Guarantee | Standard & Poors, No Rating |  |  |
Summary of Ceded Par and Net Unsecured Reinsurance Recoverable [Line Items] |  |  |
Reinsurance Recoverables, Gross | 21,937 |  |
Unsecured Reinsurance Recoverables | $ 0 |  |

X
- Definition Ceded Loss And Loss Expenses Paid Not Yet Recovered + References No definition available. + Details
Name: | ambc_CededLossAndLossExpensesPaidNotYetRecovered
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition 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. + References No definition available. + Details
Name: | ambc_DeferredCededPremiumsAndReinsuranceRecoverables
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of Reinsurers Covering Majority + References No definition available. + Details
Name: | ambc_NumberOfReinsurersCoveringMajority
Namespace Prefix: | ambc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of Ceded Reinsurance Recoverable Represented by Top Three + References No definition available. + Details
Name: | ambc_PercentageOfCededReinsuranceRecoverableRepresentedByTopThree
Namespace Prefix: | ambc_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Reinsurance Recoverable Credit Exposure + References No definition available. + Details
Name: | ambc_ReinsuranceRecoverableCreditExposure
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Reinsurance Recoverable, Gross, All Other + References No definition available. + Details
Name: | ambc_ReinsuranceRecoverableGrossAllOther
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Summary of Ceded Par and Net Unsecured Reinsurance Recoverable [Line Items] + References No definition available. + Details
Name: | ambc_SummaryOfCededParAndNetUnsecuredReinsuranceRecoverableLineItems
Namespace Prefix: | ambc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Uncollateralized Credit Exposure Supoorted by Unlimited Uncapped Indemnity + References No definition available. + Details
Name: | ambc_UncollateralizedCreditExposureSupoortedByUnlimitedUncappedIndemnity
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Unsecured Reinsurance Recoverable, All Other + References No definition available. + Details
Name: | ambc_UnsecuredReinsuranceRecoverableAllOther
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition 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. + References No definition available. + Details
Name: | ambc_UnsecuredReinsuranceRecoverables
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The total amount of the contingent obligation under letters of credit outstanding as of the reporting date. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 605 -Name Accounting Standards Codification -Section 55 -Paragraph 15 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477548/944-605-55-15 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 605 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477548/944-605-55-12 + Details
Name: | us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of allowance for credit loss on reinsurance recoverable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 310 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477363/944-310-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 310 -Name Accounting Standards Codification -Section 45 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477409/944-310-45-6 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479838/944-20-50-5 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 310 -Name Accounting Standards Codification -Section 45 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477409/944-310-45-5 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 + Details
Name: | us-gaap_ReinsuranceRecoverablesAllowance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount before valuation allowance recoverable under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, premium paid, policy benefits and policy reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 310 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477363/944-310-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 310 -Name Accounting Standards Codification -Section 45 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477409/944-310-45-6 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 605 -Name Accounting Standards Codification -Section 55 -Paragraph 14 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477548/944-605-55-14 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 605 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477548/944-605-55-12 Reference 5: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7A -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-7A Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479838/944-20-50-5 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(6)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 310 -Name Accounting Standards Codification -Section 45 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477409/944-310-45-5 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 14 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-14 + Details
Name: | us-gaap_ReinsuranceRecoverablesGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_CededCreditRiskAxis=ambc_QBEInsuranceCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ScheduleOfMalpracticeInsuranceTypeAndTierIdentifierAxis=us-gaap_PropertyAndCasualtyCommercialInsuranceProductLineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingStandardPoorsAxis=srt_StandardPoorsARatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CededCreditRiskAxis=ambc_AssuredGuarantyReLtdMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ScheduleOfMalpracticeInsuranceTypeAndTierIdentifierAxis=ambc_LegacyFinancialGuaranteeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingStandardPoorsAxis=srt_StandardPoorsAPlusRatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CededCreditRiskAxis=ambc_GeneralReinsuranceCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingStandardPoorsAxis=ambc_StandardPoorsAPlusPlusRating
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CededCreditRiskAxis=ambc_SwissReinsuranceAmericaCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingStandardPoorsAxis=ambc_StandardPoorsNoRatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |