XML 95 R74.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions | Dec. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items] |  |
Other Investments | $ 475 | $ 568
Fair value of derivative liabilities | 35 |
Derivative liabilities | $ 35 | $ 38
Weighted average discounted rate of estimated future premium payments to be paid by the VIEs | 3.20% | 3.00%
Fixed Income Securities [Member] |  |
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items] |  |
Percentage of investment portfolio valued using dealer quotes | 2.00% | 5.00%
Asset-backed Securities [Member] |  |
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items] |  |
Coupon rate | 5.97% | 5.98%
Minimum [Member] | Fixed Income Securities [Member] |  |
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items] |  |
Percentage of investment portfolio valued using internal valuation models | 4.00% | 4.00%
Maximum [Member] | Fixed Income Securities [Member] |  |
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items] |  |
Percentage of investment portfolio valued using external pricing services | 94.00% | 91.00%
Variable Interest Entity, Primary Beneficiary [Member] |  |
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items] |  |
Fair value of derivative liabilities | $ 0 |
Derivative liabilities | $ 1,197 | $ 1,048
Weighted average discounted rate of estimated future premium payments to be paid by the VIEs | 6.30% | 6.80%
Real Estate [Member] |  |
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items] |  |
Other Investments | $ 21 | $ 22
Hedge Funds, Multi-strategy [Member] |  |
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items] |  |
Other Investments | 112 | 186
Interest Rate Contract [Member] |  |
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items] |  |
Other Investments | 85 | 80
Illiquid Investments [Member] |  |
Fair Value Of Assets And Liabilities Measured On Non Recurring Basis [Line Items] |  |
Other Investments | $ 84 | $ 84

X
- Definition Weighted average discounted rate of estimated future premium payments to be paid by the VIEs. + References No definition available. + Details
Name: | ambc_EstimatedFuturePremiumPaymentsWeightedAverageDiscountedRate
Namespace Prefix: | ambc_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fair value inputs coupon rate. + References No definition available. + Details
Name: | ambc_FairValueInputsCouponRate
Namespace Prefix: | ambc_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Investment portfolio valued using dealer quotes. + References No definition available. + Details
Name: | ambc_PercentageOfInvestmentPortfolioValuedUsingDealerQuotes
Namespace Prefix: | ambc_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of investment portfolio valued using external pricing services. + References No definition available. + Details
Name: | ambc_PercentageOfInvestmentPortfolioValuedUsingExternalPricingServices
Namespace Prefix: | ambc_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of investment portfolio valued using internal valuation models. + References No definition available. + Details
Name: | ambc_PercentageOfInvestmentPortfolioValuedUsingInternalValuationModels
Namespace Prefix: | ambc_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 22 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483444/210-20-55-22 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483466/210-20-50-3 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483444/210-20-55-7 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-4B Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 4D -Subparagraph (c)(2) -SubTopic 20 -Topic 860 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481326/860-20-50-4D + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value, after offset of derivative asset, of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 55 -Paragraph 9 -SubTopic 20 -Topic 210 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483444/210-20-55-9 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -SubTopic 20 -Topic 210 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483466/210-20-50-3 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 55 -Paragraph 10 -SubTopic 20 -Topic 210 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483444/210-20-55-10 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 8 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-8 + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482106/820-10-50-3 + Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of investments classified as other. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(12)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_OtherInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_FixedIncomeSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_RealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_HedgeFundsMultistrategyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_InterestRateContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=ambc_IlliquidInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |