XML 53 R38.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Special Purpose Entities, Including Variable Interest Entities - Additional Information (Detail) $ in Thousands | 1 Months Ended | 3 Months Ended | 6 Months Ended |  |
--- | --- | --- | --- | --- | ---
Jul. 31, 2015 USD ($) | Jun. 30, 2018 USD ($) Entity | Jun. 30, 2017 USD ($) | Jun. 30, 2018 USD ($) Entity | Jun. 30, 2017 USD ($) | Feb. 12, 2018 USD ($) | Dec. 31, 2017 USD ($) Entity
Variable Interest Entities [Line Items] |  |  |  |  |  |  |
Equity Method Investments |  | $ 37,497 |  | $ 37,497 |  |  | $ 34,941
Number of RMBS Sold | 17 |  |  |  |  |  |
Cash Received From Delaware Trust | $ 146,000 |  |  |  |  |  |
Secured Debt |  | 0 |  | 0 |  |  | 73,993
Fair Value of Securities Placed in Trust |  | 0 |  | 0 |  |  | 346,212
Securities Issued by Delaware Trust | $ 146,000 |  |  |  |  |  |
Consolidated VIE assets |  | 13,570,666 |  | 13,570,666 |  |  | 14,500,507
Consolidated VIE liabilities |  | 13,447,562 |  | 13,447,562 |  |  | 14,366,434
Successor [Member] |  |  |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |  |  |
Variable Interest Entity Change in Fair Value of Assets and Liabilities |  | (450) | $ (1,219) | 1,468 | $ 2,482 |  |
Fair value of special purpose entities |  | 5,255 |  | 5,255 |  |  | 5,979
variable interest entities deconsolidation gain loss |  | 0 | 0 | 0 | 0 |  |
Variable Interest Entity, Measure of Activity, Income or Loss before Tax |  | 577 | (1,219) | 1,151 | 2,482 |  |
Other investments |  | 394,396 |  | $ 394,396 |  |  | 431,630
Asset-Backed Securities and Utility Obligations [Member] |  |  |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |  |  |
Weighted average life |  |  |  | 2 years 6 months 25 days |  |  |
Average rating of assets held by sponsored special purpose entities |  |  |  | BBB+ |  |  |
Sponsored Variable Interest Entities [Member] |  |  |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |  |  |
Total principal amount of debt outstanding |  | 410,760 |  | $ 410,760 |  |  | $ 420,600
Variable Interest Entities [Member] |  |  |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |  |  |
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Reclassification Adjustment from AOCI for Derecognition, before Tax |  | $ 1,027 | $ 0 | $ (317) | $ 0 |  |
Consolidated Entities [Member] |  |  |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |  |  |
Number of Newly Consolidated Variable Interest Entities |  | 0 | 0 |  | 0 |  |
Number of DeConsolidated Variable Interest Entities |  | 0 | 0 | 0 | 0 |  |
Number of consolidated Variable Interest Entities | Entity |  | 11 |  | 11 |  |  | 11
Ambac UK [Member] |  |  |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |  |  |
Number of consolidated Variable Interest Entities | Entity |  | 8 |  | 8 |  |  | 8
Consolidated VIE assets |  | $ 13,274,042 |  | $ 13,274,042 |  |  | $ 14,160,152
Consolidated VIE liabilities |  | 13,151,223 |  | 13,151,223 |  |  | $ 14,026,704
Ambac Assurance [Member] |  |  |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |  |  |
Number of consolidated Variable Interest Entities | Entity |  |  |  |  |  |  | 3
Secured Notes Received from Ambac LSNI |  |  |  |  |  | $ 643,583 |
CarryValueSecuredNotesfromLSNI |  | 621,849 |  | 621,849 |  |  |
Unsettled Amounts Secured Notes from LSNI |  | 50,878 |  | 50,878 |  |  |
Afg [Member] |  |  |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |  |  |
Secured Notes Received from Ambac LSNI |  |  |  |  |  | $ 124,881 |
CarryValueSecuredNotesfromLSNI |  | 120,233 |  | 120,233 |  |  |
Unsettled Amounts Secured Notes from LSNI |  | $ 9,837 |  | $ 9,837 |  |  |
London Interbank Offered Rate (LIBOR) [Member] |  |  |  |  |  |  |
Variable Interest Entities [Line Items] |  |  |  |  |  |  |
Interest Rate on Securities Issued by Delaware Trust | 2.80% |  |  |  |  |  |

X
- Definition CarryValueSecuredNotesfromLSNI + References No definition available. + Details
Name: | ambc_CarryValueSecuredNotesfromLSNI
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Cash Received From Delaware Trust + References No definition available. + Details
Name: | ambc_CashReceivedFromDelawareTrust
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The total principal amount of outstanding debt issued by Ambac's sponsored medium term note special purpose entities. + References No definition available. + Details
Name: | ambc_FaceAmountOfDebtOutstandingIssuedBySponsoredSpecialPurposeEntities
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair Value of Securities Placed in Trust + References No definition available. + Details
Name: | ambc_FairValueofSecuritiesPlacedinTrust
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Interest Rate on Securities Issued by Delaware Trust + References No definition available. + Details
Name: | ambc_InterestRateonSecuritiesIssuedbyDelawareTrust
Namespace Prefix: | ambc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of consolidated variable interest entities. + References No definition available. + Details
Name: | ambc_NumberOfConsolidatedVariableInterestEntities
Namespace Prefix: | ambc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of DeConsolidated Variable Interest Entities + References No definition available. + Details
Name: | ambc_NumberofDeConsolidatedVariableInterestEntities
Namespace Prefix: | ambc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of Newly Consolidated Variable Interest Entities + References No definition available. + Details
Name: | ambc_NumberofNewlyConsolidatedVariableInterestEntities
Namespace Prefix: | ambc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of RMBS Sold + References No definition available. + Details
Name: | ambc_NumberofRMBSSold
Namespace Prefix: | ambc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Secured Notes Received from Ambac LSNI + References No definition available. + Details
Name: | ambc_SecuredNotesReceivedfromAmbacLSNI
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Securities Issued by Delaware Trust + References No definition available. + Details
Name: | ambc_SecuritiesIssuedbyDelawareTrust
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Unsettled Amounts Secured Notes from LSNI + References No definition available. + Details
Name: | ambc_UnsettledAmountsSecuredNotesfromLSNI
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Variable Interest Entity Change in Fair Value of Assets and Liabilities + References No definition available. + Details
Name: | ambc_VariableInterestEntityChangeinFairValueofAssetsandLiabilities
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition variable interest entities deconsolidation gain loss + References No definition available. + Details
Name: | ambc_Variableinterestentitiesdeconsolidationgainloss
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The weighted average remaining life of assets held by Ambac's sponsored medium term note special purpose entities at the reporting date. + References No definition available. + Details
Name: | ambc_WeightedAverageLifeOfAssetsHeldBySponsoredSpecialPurposeEntities
Namespace Prefix: | ambc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The weighted average credit rating of assets held by Ambac's sponsored medium term note special purpose entities at the reporting date. + References No definition available. + Details
Name: | ambc_WeightedAverageRatingOfAssetsHeldBySponsoredSpecialPurposeEntities
Namespace Prefix: | ambc_
Data Type: | us-types:durationStringItemType
Balance Type: | na
Period Type: | duration

X
- Definition This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=66022249&loc=d3e33749-111570 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_EquityMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of investments accounted under the equity method. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 25 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=66022186&loc=d3e32014-111567 + Details
Name: | us-gaap_EquityMethodInvestmentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, before tax, of reclassification adjustment from accumulated other comprehensive income (loss) for unrealized gain (loss) from increase (decrease) in instrument-specific credit risk, realized upon derecognition of financial liability measured under fair value option. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e637-108580 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e689-108580 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (l) -URI http://asc.fasb.org/extlink&oid=84228862&loc=SL7669646-108580 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=75026489&loc=SL75136633-108610 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionReclassificationAdjustmentFromAociForDerecognitionBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of investments classified as other. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.1(f,g)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_OtherInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_SecuredDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Description of the amount of pre-tax income (loss) derived by the reporting entity from the Variable Interest Entity (VIE). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph d -URI http://asc.fasb.org/extlink&oid=77990344&loc=d3e5747-111685 + Details
Name: | us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityIncomeOrLossBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The carrying amount of the consolidated Variable Interest Entity's assets included in the reporting entity's statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (bb) -URI http://asc.fasb.org/extlink&oid=77990344&loc=d3e5710-111685 + Details
Name: | us-gaap_VariableInterestEntityConsolidatedCarryingAmountAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The carrying amount of the consolidated Variable Interest Entity's liabilities included in the reporting entity's statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (bb) -URI http://asc.fasb.org/extlink&oid=77990344&loc=d3e5710-111685 + Details
Name: | us-gaap_VariableInterestEntityConsolidatedCarryingAmountLiabilities
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 No definition available. + Details
Name: | us-gaap_VariableInterestEntityLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_SuccessorMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=ambc_AssetBackedSecuritiesAndUtilityObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryAggregatedDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConsolidatedEntitiesAxis=us-gaap_ConsolidatedEntitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |