XML 108 R40.htm IDEA: XBRL DOCUMENT
v3.26.1

Business and Basis of Presentation Noncontrolling Interests (Details) - USD ($) $ in Thousands | 3 Months Ended |  |  |
--- | --- | --- | --- | ---
Mar. 31, 2026 | Mar. 31, 2025 | Dec. 31, 2026 | Dec. 31, 2025 | Dec. 31, 2024
Background And Basis Of Presentation [Line Items] |  |  |  |  |
Foreign Exchange | $ (4,193) | $ 5,658 |  |  |
Stockholders' Equity Attributable to Noncontrolling Interest | 120,956 |  |  | $ 117,395 |
Reclassification from nonredeemable noncontrolling interest including remeasurement at fair value | 0 | 42,180 |  |  |
Reclassification to nonredeemable noncontrolling interest | (3,841) | (1,877) |  |  |
Put / call option exercise | (49,708) | 0 |  |  |
Redeemable Noncontrolling Interest, Equity, Carrying Amount | 195,969 | 245,461 |  | $ 252,981 | $ 199,402
Net Income (Loss) Attributable to Redeemable Noncontrolling Interest | 1,980 | 258 |  |  |
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders | (443) | (708) |  |  |
Temporary Equity, Accretion to Redemption Value, Adjustment | (807) | 548 |  |  |
Payments for Repurchase of Redeemable Noncontrolling Interest | $ 494 |  |  |  |
Previously Reported |  |  |  |  |
Background And Basis Of Presentation [Line Items] |  |  |  |  |
Foreign Exchange |  | 3,797 |  |  |
Reclassification from nonredeemable noncontrolling interest including remeasurement at fair value |  | 42,180 |  |  |
Reclassification to nonredeemable noncontrolling interest |  | (1,877) |  |  |
Redeemable Noncontrolling Interest, Equity, Carrying Amount |  | 185,417 |  |  | 140,860
Net Income (Loss) Attributable to Redeemable Noncontrolling Interest |  | 258 |  |  |
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders |  | (708) |  |  |
Temporary Equity, Accretion to Redemption Value, Adjustment |  | 907 |  |  |
Revision of Prior Period, Adjustment |  |  |  |  |
Background And Basis Of Presentation [Line Items] |  |  |  |  |
Foreign Exchange |  | 1,861 |  |  |
Redeemable Noncontrolling Interest, Equity, Carrying Amount |  | 60,044 |  |  | $ 58,542
Temporary Equity, Accretion to Redemption Value, Adjustment |  | $ (359) |  |  |
Capacity Marine |  |  |  |  |
Background And Basis Of Presentation [Line Items] |  |  |  |  |
Business Combination, Voting Equity Interest Acquired, Percentage | 87.00% |  |  | 80.00% |
Octave Ventures |  |  |  |  |
Background And Basis Of Presentation [Line Items] |  |  |  |  |
Business Combination, Voting Equity Interest Acquired, Percentage | 70.00% |  |  | 60.00% |
Octave Specialty Limited |  |  |  |  |
Background And Basis Of Presentation [Line Items] |  |  |  |  |
Redeemable Noncontrolling Interest, Equity, Other, Carrying Amount | $ 49,214 |  |  |  |
Payable for Redeemable Noncontrolling Interest | $ 43,644 |  |  |  |
Octave Specialty Limited | Octave Specialty Limited | Maximum [Member] |  |  |  |  |
Background And Basis Of Presentation [Line Items] |  |  |  |  |
Subsidiary, Ownership Percentage, Noncontrolling Owner | 100.00% |  | 100.00% |  |
Subsidiary, Ownership Percentage, Parent | 70.00% |  |  | 60.00% |
Octave Specialty Limited | Octave Specialty Limited | Minimum [Member] |  |  |  |  |
Background And Basis Of Presentation [Line Items] |  |  |  |  |
Subsidiary, Ownership Percentage, Noncontrolling Owner | 51.00% |  | 60.00% |  |
Subsidiary, Ownership Percentage, Parent | 36.00% |  |  | 36.00% |
Capacity Marine |  |  |  |  |
Background And Basis Of Presentation [Line Items] |  |  |  |  |
Redeemable Noncontrolling Interest, Equity, Other, Carrying Amount | $ 383 |  |  |  |

X
- Definition Background And Basis Of Presentation [Line Items] + References No definition available. + Details
Name: | ambc_BackgroundAndBasisOfPresentationLineItems
Namespace Prefix: | ambc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Payable for Redeemable Noncontrolling Interest + References No definition available. + Details
Name: | ambc_PayableForRedeemableNoncontrollingInterest
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Put / call option exercise + References No definition available. + Details
Name: | ambc_PutCallOptionExercise
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Reclassification from nonredeemable noncontrolling interest including remeasurement at fair value + References No definition available. + Details
Name: | ambc_ReclassificationFromNonredeemableNoncontrollingInterestIncludingRemeasurementAtFairValue
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Reclassification to nonredeemable noncontrolling interest + References No definition available. + Details
Name: | ambc_ReclassificationToNonredeemableNoncontrollingInterest
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Percentage of voting equity interest acquired in business combination. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 805 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479328/805-10-50-8 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 805 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 38 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479303/805-10-55-38 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 805 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479328/805-10-50-2 + Details
Name: | us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of equity (deficit) attributable to noncontrolling interest. Excludes temporary equity. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(i)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 28 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-28 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(31)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481687/323-10-50-3 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(24)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(19)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(i)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1A Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iv)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1A Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(5)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1A Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(i)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1B Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iv)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1B Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(5)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1B Reference 15: 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(22)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 + Details
Name: | us-gaap_MinorityInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Decrease in noncontrolling interest balance from payment of dividends or other distributions by the non-wholly owned subsidiary or partially owned entity, included in the consolidation of the parent entity, to the noncontrolling interest holders. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1 + Details
Name: | us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity. + References No definition available. + Details
Name: | us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The parent entity's interest in net assets of the subsidiary, expressed as a percentage. + References No definition available. + Details
Name: | us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of Net Income (Loss) attributable to redeemable noncontrolling interest. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(19)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2 + Details
Name: | us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash outflow during the period for redemption of redeemable noncontrolling interests. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 15 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-15 + Details
Name: | us-gaap_PaymentsForRepurchaseOfRedeemableNoncontrollingInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition As of the reporting date, the aggregate carrying amount of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479887/480-10-S45-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479857/480-10-S50-3 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S45 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479887/480-10-S45-3 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3A -Subparagraph (24) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480244/480-10-S99-3A Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (01)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480244/480-10-S99-1 + Details
Name: | us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of noncontrolling interests which are redeemable by the parent entity, classified as other equity. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479857/480-10-S50-3 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S45 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479887/480-10-S45-3 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3A -Subparagraph (24) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480244/480-10-S99-3A + Details
Name: | us-gaap_RedeemableNoncontrollingInterestEquityOtherCarryingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of decrease to net income for accretion of temporary equity to its redemption value to derive net income apportioned to common stockholders. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479857/480-10-S50-3 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S45 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479887/480-10-S45-3 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3A -Subparagraph (24)(d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480244/480-10-S99-3A + Details
Name: | us-gaap_TemporaryEquityAccretionToRedemptionValueAdjustment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Adjustments to temporary equity resulting from foreign currency translation adjustments. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479857/480-10-S50-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479887/480-10-S45-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (04) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480244/480-10-S99-1 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 480 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (01) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480244/480-10-S99-1 + Details
Name: | us-gaap_TemporaryEquityForeignCurrencyTranslationAdjustments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | srt_RestatementAxis=srt_ScenarioPreviouslyReportedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RestatementAxis=srt_RestatementAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=ambc_CapacityMarineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=ambc_OctaveVenturesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=ambc_OctaveSpecialtyLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_OwnershipAxis=ambc_OctaveSpecialtyLimitedMember
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_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=ambc_CapacityMarineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |