XML 87 R66.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Investments - Additional Information (Detail) - USD ($) $ in Millions | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
--- | --- | --- | --- | ---
Reported Value Measurement [Member] |  |  |  |
Investment [Table] |  |  |  |
Other Investments | $ 77 | $ 61 |  |
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 28 | 44 |  |
Reported Value Measurement [Member] | Interest Rate Contract [Member] |  |  |  |
Investment [Table] |  |  |  |
Other Investments | 39 | 0 |  |
Reported Value Measurement [Member] | Equity [Member] |  |  |  |
Investment [Table] |  |  |  |
Other Investments | 38 | 53 |  |
Reported Value Measurement [Member] | Convertibles and Bonds with Warrants Attached |  |  |  |
Investment [Table] |  |  |  |
Other Investments | 0 | 8 |  |
Other Investments | 475 | 568 |  |
Securities fair value | 24 | 23 |  |
Fair Value of Securities Deposited in Connection wtih Letter of Credit | 1 |  |  |
Debt Securities, Available-for-sale, Allowance for Credit Loss | 3 | 0 |  |
Equity Securities Excluded From Fair Value | 13 | 12 |  |
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 274 | 61 | $ 23 | $ 35
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 28 | 44 |  |
Insurance Distribution |  |  |  |
Investment [Table] |  |  |  |
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents | 2 | 0 |  |
Real Estate [Member] |  |  |  |
Investment [Table] |  |  |  |
Other Investments | 21 | 22 |  |
Hedge Funds, Multi-strategy [Member] |  |  |  |
Investment [Table] |  |  |  |
Other Investments | 112 | 186 |  |
Interest Rate Contract [Member] |  |  |  |
Investment [Table] |  |  |  |
Other Investments | 85 | 80 |  |
Illiquid Investments [Member] |  |  |  |
Investment [Table] |  |  |  |
Other Investments | 84 | 84 |  |
Insurance Linked [Member] |  |  |  |
Investment [Table] |  |  |  |
Other Investments | 1 | 1 |  |
Equity [Member] |  |  |  |
Investment [Table] |  |  |  |
Other Investments | 38 | 64 |  |
Credit Index Product [Member] |  |  |  |
Investment [Table] |  |  |  |
Other Investments | 52 | 63 |  |
Equity investments in pooled funds [Member] |  |  |  |
Investment [Table] |  |  |  |
Other Investments | 463 | 556 |  |
Private Equity Funds, US |  |  |  |
Investment [Table] |  |  |  |
Other Investments | 70 | 47 |  |
Convertibles and Bonds with Warrants Attached |  |  |  |
Investment [Table] |  |  |  |
Other Investments | 0 | 8 |  |
Investment Portfolio [Member] |  |  |  |
Investment [Table] |  |  |  |
Fair Value of Cash and Securities Pledged to Derivative Counterparties | 27 | $ 64 |  |
Commitments [Member] | Private Equity Funds |  |  |  |
Investment [Table] |  |  |  |
Other Investments | $ 41 |  |  |

X
- Definition Equity Securities Excluded From Fair Value + References No definition available. + Details
Name: | ambc_EquitySecuritiesExcludedFromFairValue
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of cash and securities pledged to derivative counterparties. + References No definition available. + Details
Name: | ambc_FairValueOfCashAndSecuritiesPledgedToDerivativeCounterparties
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of securities deposited with governmental authorities. + References No definition available. + Details
Name: | ambc_FairValueOfSecuritiesDepositedWithGovernmentalAuthorities
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair Value of Securities Deposited in Connection wtih Letter of Credit + References No definition available. + Details
Name: | ambc_FairValueofSecuritiesDepositedinConnectionwtihLetterofCredit
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage. Excludes amount for disposal group and discontinued operations. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482913/230-10-50-8 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 24 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-24 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-4 + Details
Name: | us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (aaa) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479130/326-30-45-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479106/326-30-50-9 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (i) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479106/326-30-50-9 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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
- 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 No definition available. + Details
Name: | us-gaap_PurchaseCommitmentExcludingLongtermCommitmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of cash and cash equivalents restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(1)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(2)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482913/230-10-50-8 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(1)(a)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-4 + Details
Name: | us-gaap_RestrictedCashAndCashEquivalents
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
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=us-gaap_EquityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

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

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

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

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=ambc_InvestmentPortfolioMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_OtherCommitmentsAxis=us-gaap_CommitmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_PrivateEquityFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |