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Fair Value Measurements - Summary of Carrying Amount and Fair Value of Ambac's Financial Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified | Mar. 31, 2015 | Dec. 31, 2014
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Financial assets: |  |
Other investments | $ 310,578 us-gaap_OtherInvestments | $ 240,969 us-gaap_OtherInvestments
Other assets | 10,036 us-gaap_EquityMethodInvestmentsFairValueDisclosure | 12,036 us-gaap_EquityMethodInvestmentsFairValueDisclosure
Financial liabilities: |  |
Derivative liabilities | 76,377 us-gaap_DerivativeFairValueOfDerivativeLiability | 73,459 us-gaap_DerivativeFairValueOfDerivativeLiability
Successor [Member] |  |
Financial assets: |  |
Fixed income securities | 5,151,543 us-gaap_AvailableForSaleSecurities / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 5,150,018 us-gaap_AvailableForSaleSecurities / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Short term investments | 220,980 us-gaap_OtherShortTermInvestments / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 360,065 us-gaap_OtherShortTermInvestments / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Other investments | 328,187 us-gaap_OtherInvestments / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 349,468 us-gaap_OtherInvestments / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Cash | 26,641 us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 73,903 us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Loans | 5,476 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 5,634 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Total financial assets | 21,135,582 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 20,822,011 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Financial liabilities: |  |
Obligations under investment and repurchase agreements | 114,438 ambc_GuaranteedInvestmentAgreementsFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 161,821 ambc_GuaranteedInvestmentAgreementsFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Liabilities for net financial guarantees written | 4,152,094 us-gaap_GuaranteesFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 4,539,000 us-gaap_GuaranteesFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Long-term debt | 1,381,938 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 1,379,864 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Total financial liabilities | 21,563,441 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 21,569,868 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Total Fair Value [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Restricted cash | 6,219 ambc_RestrictedCashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 7,708 ambc_RestrictedCashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Loans | 12,789,201 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 12,371,177 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Financial liabilities: |  |
Long-term debt | 13,341,902 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 12,882,076 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Successor [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Other investments | 332,609 us-gaap_OtherInvestments / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 357,016 us-gaap_OtherInvestments / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Cash | 26,641 us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 73,903 us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Loans | 5,494 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 5,714 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Total financial assets | 21,140,022 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 20,829,639 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Financial liabilities: |  |
Obligations under investment and repurchase agreements | 111,967 ambc_GuaranteedInvestmentAgreementsFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 160,079 ambc_GuaranteedInvestmentAgreementsFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Liabilities for net financial guarantees written | 2,662,701 us-gaap_GuaranteesFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 2,923,652 us-gaap_GuaranteesFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Long-term debt | 1,301,390 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 1,273,805 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Total financial liabilities | 19,991,029 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 19,846,719 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Carrying Amount [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Restricted cash | 6,219 ambc_RestrictedCashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 7,708 ambc_RestrictedCashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Loans | 12,789,201 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 12,371,177 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Financial liabilities: |  |
Long-term debt | 13,341,902 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 12,882,076 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Successor [Member] | Level 1 [Member] |  |
Financial assets: |  |
Other investments | 0 us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Cash | 26,641 us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 73,903 us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Loans | 0 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Total financial assets | 343,177 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 547,047 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Financial liabilities: |  |
Obligations under investment and repurchase agreements | 0 ambc_GuaranteedInvestmentAgreementsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 ambc_GuaranteedInvestmentAgreementsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Liabilities for net financial guarantees written | 0 us-gaap_GuaranteesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_GuaranteesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Long-term debt | 0 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Total financial liabilities | 942 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 562 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Level 1 [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Restricted cash | 6,219 ambc_RestrictedCashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 7,708 ambc_RestrictedCashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Loans | 0 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 0 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Financial liabilities: |  |
Long-term debt | 0 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 0 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Successor [Member] | Level 2 [Member] |  |
Financial assets: |  |
Other investments | 310,578 us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 336,013 us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Cash | 0 us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Loans | 0 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Total financial assets | 5,002,694 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 4,929,368 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Financial liabilities: |  |
Obligations under investment and repurchase agreements | 0 ambc_GuaranteedInvestmentAgreementsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 ambc_GuaranteedInvestmentAgreementsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Liabilities for net financial guarantees written | 0 us-gaap_GuaranteesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_GuaranteesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Long-term debt | 0 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Total financial liabilities | 13,651,729 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 14,007,568 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Level 2 [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Restricted cash | 0 ambc_RestrictedCashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 0 ambc_RestrictedCashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Loans | 0 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 0 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Financial liabilities: |  |
Long-term debt | 11,309,803 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 11,618,412 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Successor [Member] | Level 3 [Member] |  |
Financial assets: |  |
Other investments | 17,609 us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 13,455 us-gaap_OtherInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Cash | 0 us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Loans | 5,476 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 5,634 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Total financial assets | 15,789,711 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 15,345,596 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Financial liabilities: |  |
Obligations under investment and repurchase agreements | 114,438 ambc_GuaranteedInvestmentAgreementsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 161,821 ambc_GuaranteedInvestmentAgreementsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Liabilities for net financial guarantees written | 4,152,094 us-gaap_GuaranteesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 4,539,000 us-gaap_GuaranteesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Long-term debt | 1,381,938 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 1,379,864 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Total financial liabilities | 7,910,770 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 7,561,738 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Level 3 [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Restricted cash | 0 ambc_RestrictedCashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 0 ambc_RestrictedCashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Loans | 12,789,201 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 12,371,177 us-gaap_LoansReceivableFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Financial liabilities: |  |
Long-term debt | 2,032,099 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 1,263,664 us-gaap_LongTermDebtFairValue / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Successor [Member] | Level 3 [Member] | Currency Swaps [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CurrencySwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember |
Successor [Member] | Interest Rate Swaps [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Derivative assets | 113,622 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 106,974 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Derivative assets - interest rate swaps - liability position | 0 us-gaap_DerivativeAssetFairValueGrossLiability / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Successor [Member] | Interest Rate Swaps [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Derivative assets | 113,622 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 106,974 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Derivative assets - interest rate swaps - liability position | 0 us-gaap_DerivativeAssetFairValueGrossLiability / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember |
Successor [Member] | Interest Rate Swaps [Member] | Level 1 [Member] |  |
Financial assets: |  |
Derivative assets | 0 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Derivative assets - interest rate swaps - liability position | 0 us-gaap_DerivativeAssetFairValueGrossLiability / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_DerivativeAssetFairValueGrossLiability / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Interest Rate Swaps [Member] | Level 2 [Member] |  |
Financial assets: |  |
Derivative assets | 113,622 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 106,974 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Derivative assets - interest rate swaps - liability position | 0 us-gaap_DerivativeAssetFairValueGrossLiability / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_DerivativeAssetFairValueGrossLiability / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Interest Rate Swaps [Member] | Level 3 [Member] |  |
Financial assets: |  |
Derivative assets | 0 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Derivative assets - interest rate swaps - liability position | 0 us-gaap_DerivativeAssetFairValueGrossLiability / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_DerivativeAssetFairValueGrossLiability / us-gaap_FairValueByAssetClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Municipal Bonds [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Fixed income securities | 525,188 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_MunicipalBondsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 525,792 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_MunicipalBondsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Municipal Bonds [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Fixed income securities | 525,188 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_MunicipalBondsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 525,792 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_MunicipalBondsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Municipal Bonds [Member] | Level 1 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_MunicipalBondsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_MunicipalBondsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Municipal Bonds [Member] | Level 2 [Member] |  |
Financial assets: |  |
Fixed income securities | 525,188 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_MunicipalBondsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 525,792 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_MunicipalBondsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Municipal Bonds [Member] | Level 3 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_MunicipalBondsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_MunicipalBondsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Corporate Obligations [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Fixed income securities | 1,609,769 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 1,385,594 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Corporate Obligations [Member] | Total Fair Value [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Fixed income securities | 2,704,657 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 2,743,050 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Successor [Member] | Corporate Obligations [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Fixed income securities | 1,609,769 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 1,385,594 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Corporate Obligations [Member] | Carrying Amount [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Fixed income securities | 2,704,657 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 2,743,050 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Successor [Member] | Corporate Obligations [Member] | Level 1 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Corporate Obligations [Member] | Level 1 [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Successor [Member] | Corporate Obligations [Member] | Level 2 [Member] |  |
Financial assets: |  |
Fixed income securities | 1,609,769 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 1,381,786 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Corporate Obligations [Member] | Level 2 [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Successor [Member] | Corporate Obligations [Member] | Level 3 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 3,808 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Corporate Obligations [Member] | Level 3 [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Fixed income securities | 2,704,657 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 2,743,050 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Successor [Member] | Foreign Obligations [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Fixed income securities | 125,164 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 127,757 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Foreign Obligations [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Fixed income securities | 125,164 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 127,757 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Foreign Obligations [Member] | Level 1 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Foreign Obligations [Member] | Level 2 [Member] |  |
Financial assets: |  |
Fixed income securities | 125,164 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 127,757 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Foreign Obligations [Member] | Level 3 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ForeignGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | US Government Debt Securities [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Fixed income securities | 30,297 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 42,979 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Fixed income securities, pledged as collateral | 64,813 us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 64,267 us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | US Government Debt Securities [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Fixed income securities | 30,297 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 42,979 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Fixed income securities, pledged as collateral | 64,813 us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 64,267 us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | US Government Debt Securities [Member] | Level 1 [Member] |  |
Financial assets: |  |
Fixed income securities | 30,297 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 42,979 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Fixed income securities, pledged as collateral | 64,813 us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 64,267 us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | US Government Debt Securities [Member] | Level 2 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Fixed income securities, pledged as collateral | 0 us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | US Government Debt Securities [Member] | Level 3 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Fixed income securities, pledged as collateral | 0 us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | U.S. Agency Obligations [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Fixed income securities | 4,427 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 29,486 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | U.S. Agency Obligations [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Fixed income securities | 4,427 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 29,486 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | U.S. Agency Obligations [Member] | Level 1 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | U.S. Agency Obligations [Member] | Level 2 [Member] |  |
Financial assets: |  |
Fixed income securities | 4,427 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 29,486 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | U.S. Agency Obligations [Member] | Level 3 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Residential Mortgage-Backed Securities [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Fixed income securities | 1,846,477 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 1,710,955 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Residential Mortgage-Backed Securities [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Fixed income securities | 1,846,477 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 1,710,955 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Residential Mortgage-Backed Securities [Member] | Level 1 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Residential Mortgage-Backed Securities [Member] | Level 2 [Member] |  |
Financial assets: |  |
Fixed income securities | 1,583,745 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 1,516,562 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Residential Mortgage-Backed Securities [Member] | Level 3 [Member] |  |
Financial assets: |  |
Fixed income securities | 262,732 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 194,393 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_ResidentialMortgageBackedSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Collateralized Debt Obligations [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Fixed income securities | 88,238 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 21,122 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Collateralized Debt Obligations [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Fixed income securities | 88,238 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 21,122 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Collateralized Debt Obligations [Member] | Level 1 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Collateralized Debt Obligations [Member] | Level 2 [Member] |  |
Financial assets: |  |
Fixed income securities | 88,238 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 21,122 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Collateralized Debt Obligations [Member] | Level 3 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CollateralizedDebtObligationsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Asset-backed Securities [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Fixed income securities | 636,190 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 882,001 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Asset-backed Securities [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Fixed income securities | 636,190 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 882,001 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Asset-backed Securities [Member] | Level 1 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Asset-backed Securities [Member] | Level 2 [Member] |  |
Financial assets: |  |
Fixed income securities | 636,190 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 882,001 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Asset-backed Securities [Member] | Level 3 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Short-Term [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Short term investments | 220,980 us-gaap_OtherShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 360,065 us-gaap_OtherShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Short-Term [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Short term investments | 220,980 us-gaap_OtherShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 360,065 us-gaap_OtherShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Short-Term [Member] | Level 1 [Member] |  |
Financial assets: |  |
Short term investments | 215,207 us-gaap_OtherShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 358,190 us-gaap_OtherShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Short-Term [Member] | Level 2 [Member] |  |
Financial assets: |  |
Short term investments | 5,773 us-gaap_OtherShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 1,875 us-gaap_OtherShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Short-Term [Member] | Level 3 [Member] |  |
Financial assets: |  |
Short term investments | 0 us-gaap_OtherShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_OtherShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_ShortTermInvestmentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Credit Derivatives [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Derivative assets | 0 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = ambc_CreditDerivativesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 2,043 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = ambc_CreditDerivativesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Credit Derivatives [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Derivative assets | 0 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = ambc_CreditDerivativesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 2,043 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = ambc_CreditDerivativesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Credit Derivatives [Member] | Level 1 [Member] |  |
Financial assets: |  |
Derivative assets | 0 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = ambc_CreditDerivativesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = ambc_CreditDerivativesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Credit Derivatives [Member] | Level 2 [Member] |  |
Financial assets: |  |
Derivative assets | 0 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = ambc_CreditDerivativesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = ambc_CreditDerivativesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Credit Derivatives [Member] | Level 3 [Member] |  |
Financial assets: |  |
Derivative assets | 0 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = ambc_CreditDerivativesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 2,043 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = ambc_CreditDerivativesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Other Assets [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Other assets | 10,036 us-gaap_EquityMethodInvestmentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_OtherAssetsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 12,036 us-gaap_EquityMethodInvestmentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_OtherAssetsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Other Assets [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Other assets | 10,036 us-gaap_EquityMethodInvestmentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_OtherAssetsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 12,036 us-gaap_EquityMethodInvestmentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_OtherAssetsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Other Assets [Member] | Level 1 [Member] |  |
Financial assets: |  |
Other assets | 0 us-gaap_EquityMethodInvestmentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_OtherAssetsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_EquityMethodInvestmentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_OtherAssetsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Other Assets [Member] | Level 2 [Member] |  |
Financial assets: |  |
Other assets | 0 us-gaap_EquityMethodInvestmentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_OtherAssetsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_EquityMethodInvestmentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_OtherAssetsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Other Assets [Member] | Level 3 [Member] |  |
Financial assets: |  |
Other assets | 10,036 us-gaap_EquityMethodInvestmentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_OtherAssetsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 12,036 us-gaap_EquityMethodInvestmentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_OtherAssetsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Futures Contracts [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Derivative assets |  | 0 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = us-gaap_FutureMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Futures Contracts [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Derivative assets |  | 0 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = us-gaap_FutureMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Futures Contracts [Member] | Level 1 [Member] |  |
Financial assets: |  |
Derivative assets |  | 0 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = us-gaap_FutureMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Futures Contracts [Member] | Level 2 [Member] |  |
Financial assets: |  |
Derivative assets |  | 0 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = us-gaap_FutureMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Successor [Member] | Futures Contracts [Member] | Level 3 [Member] |  |
Financial assets: |  |
Derivative assets |  | 0 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_FairValueByAssetClassAxis = us-gaap_FutureMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Other Contracts [Member] | Successor [Member] | Total Fair Value [Member] |  |
Financial liabilities: |  |
Derivative liabilities |  | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = ambc_OtherContractsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Other Contracts [Member] | Successor [Member] | Carrying Amount [Member] |  |
Financial liabilities: |  |
Derivative liabilities |  | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = ambc_OtherContractsMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Other Contracts [Member] | Successor [Member] | Level 1 [Member] |  |
Financial liabilities: |  |
Derivative liabilities |  | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByLiabilityClassAxis = ambc_OtherContractsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Other Contracts [Member] | Successor [Member] | Level 2 [Member] |  |
Financial liabilities: |  |
Derivative liabilities |  | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByLiabilityClassAxis = ambc_OtherContractsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Other Contracts [Member] | Successor [Member] | Level 3 [Member] |  |
Financial liabilities: |  |
Derivative liabilities |  | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByLiabilityClassAxis = ambc_OtherContractsMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Futures Contracts [Member] | Successor [Member] | Total Fair Value [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 942 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = us-gaap_FutureMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 562 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = us-gaap_FutureMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Futures Contracts [Member] | Successor [Member] | Carrying Amount [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 942 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = us-gaap_FutureMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 562 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = us-gaap_FutureMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Futures Contracts [Member] | Successor [Member] | Level 1 [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 942 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_FutureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 562 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_FutureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Futures Contracts [Member] | Successor [Member] | Level 2 [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_FutureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_FutureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Futures Contracts [Member] | Successor [Member] | Level 3 [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_FutureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_FutureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Interest Rate Swaps [Member] | Successor [Member] | Total Fair Value [Member] |  |
Financial liabilities: |  |
Derivative liabilities - interest rate swaps - asset position | (68,481)us-gaap_DerivativeLiabilityFairValueGrossAsset / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | (54,666)us-gaap_DerivativeLiabilityFairValueGrossAsset / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Derivative liabilities | 438,518 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 385,546 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Interest Rate Swaps [Member] | Successor [Member] | Total Fair Value [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 2,081,082 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 2,133,268 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Interest Rate Swaps [Member] | Successor [Member] | Carrying Amount [Member] |  |
Financial liabilities: |  |
Derivative liabilities - interest rate swaps - asset position | (68,481)us-gaap_DerivativeLiabilityFairValueGrossAsset / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | (54,666)us-gaap_DerivativeLiabilityFairValueGrossAsset / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Derivative liabilities | 438,518 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 385,546 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Interest Rate Swaps [Member] | Successor [Member] | Carrying Amount [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 2,081,082 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 2,133,268 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Interest Rate Swaps [Member] | Successor [Member] | Level 1 [Member] |  |
Financial liabilities: |  |
Derivative liabilities - interest rate swaps - asset position | 0 us-gaap_DerivativeLiabilityFairValueGrossAsset / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_DerivativeLiabilityFairValueGrossAsset / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Derivative liabilities | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Interest Rate Swaps [Member] | Successor [Member] | Level 1 [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Interest Rate Swaps [Member] | Successor [Member] | Level 2 [Member] |  |
Financial liabilities: |  |
Derivative liabilities - interest rate swaps - asset position | (68,481)us-gaap_DerivativeLiabilityFairValueGrossAsset / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | (54,666)us-gaap_DerivativeLiabilityFairValueGrossAsset / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Derivative liabilities | 284,694 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 243,659 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Interest Rate Swaps [Member] | Successor [Member] | Level 2 [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 2,081,082 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 2,133,268 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Interest Rate Swaps [Member] | Successor [Member] | Level 3 [Member] |  |
Financial liabilities: |  |
Derivative liabilities - interest rate swaps - asset position | 0 us-gaap_DerivativeLiabilityFairValueGrossAsset / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_DerivativeLiabilityFairValueGrossAsset / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Derivative liabilities | 153,824 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 141,887 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Interest Rate Swaps [Member] | Successor [Member] | Level 3 [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByLiabilityClassAxis = us-gaap_InterestRateSwapMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember / us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis = us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Credit Derivatives [Member] | Successor [Member] | Total Fair Value [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 76,377 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = ambc_CreditDerivativesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 75,502 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = ambc_CreditDerivativesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Credit Derivatives [Member] | Successor [Member] | Carrying Amount [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 76,377 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = ambc_CreditDerivativesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 75,502 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByLiabilityClassAxis = ambc_CreditDerivativesMember / us-gaap_FairValueByMeasurementBasisAxis = us-gaap_CarryingReportedAmountFairValueDisclosureMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Credit Derivatives [Member] | Successor [Member] | Level 1 [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByLiabilityClassAxis = ambc_CreditDerivativesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember | 0 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByLiabilityClassAxis = ambc_CreditDerivativesMember / us-gaap_StatementScenarioAxis = us-gaap_SuccessorMember
Credit Derivatives [Member] | Successor [Member] | Level 2 [Member] |  |
Financial liabilities: |  |
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- Definition Fair value portion of guarantee, including, but not limited to, financial standby letter of credit, fair value guarantee, guarantee of collection of scheduled contractual cash flows from financial assets, and contracts that contingently require the guarantor to make payments or perform services. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12201-110248 + Details
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- Definition Fair value of financial and nonfinancial obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258 + Details
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