XML 62 R44.htm IDEA: XBRL DOCUMENT
v3.23.1

Investments - Summary of Sources of Collateral Received and Various Investment Agreement in which Collateral Pledged (Details) - USD ($) $ in Millions | Mar. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Investment [Line Items] |  |
Fair Value Of Securities Deposited With Governmental Authorities | $ 23 | $ 23
Fair Value of Securities Deposited in Connection wtih Letter of Credit | 1 | 1
Standard & Poor's, B Rating [Member] |  |
Investment [Line Items] |  |
Investment Owned, at Fair Value | 401 | 403
Standard & Poor's, B Rating [Member] | Municipal Bonds [Member] |  |
Investment [Line Items] |  |
Investment Owned, at Fair Value | 10 | 10
Standard & Poor's, B Rating [Member] | Mortgage And Other Asset Backed Securities [Member] |  |
Investment [Line Items] |  |
Investment Owned, at Fair Value | 392 | 394
Ambac Assurance Corporation [Member] | Standard & Poor's, B Rating [Member] |  |
Investment [Line Items] |  |
Investment Owned, at Fair Value | 401 | 403
Ambac Assurance Corporation [Member] | Standard & Poor's, B Rating [Member] | Municipal Bonds [Member] |  |
Investment [Line Items] |  |
Investment Owned, at Fair Value | 10 | 10
Ambac Assurance Corporation [Member] | Standard & Poor's, B Rating [Member] | Mortgage And Other Asset Backed Securities [Member] |  |
Investment [Line Items] |  |
Investment Owned, at Fair Value | $ 392 | $ 394

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 Value of the investment at close of period. For schedules of investments that are categorized, the value would be aggregated by category. For investment in and advances to affiliates, if operations of any controlled companies are different in character from those of the company, group such affiliates within divisions and by type of activities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 210 -Section 50 -Paragraph 6 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=99383244&loc=d3e12121-115841 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 5D -Subparagraph (SX 210.12-13D(Column C)) -URI https://asc.fasb.org/extlink&oid=122147990&loc=SL120429264-123010 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-12B(Column C)) -URI https://asc.fasb.org/extlink&oid=122147990&loc=d3e611197-123010 + Details
Name: | us-gaap_InvestmentOwnedAtFairValue
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_ScheduleOfInvestmentsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_MunicipalBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=ambc_MortgageAndOtherAssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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