XML 121 R101.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Long-Term Debt (Details) - USD ($) $ in Thousands | 1 Months Ended | 3 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | ---
Jul. 31, 2015 | Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Dec. 31, 2017 | Sep. 30, 2017 | Jun. 30, 2017 | Mar. 31, 2017 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Aug. 03, 2018 | Feb. 12, 2018 | May 01, 2013
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Tier 2 Note Security in RMBS Litigation Settlement Proceeds |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,600,000 |
Long-term debt |  | $ 2,928,929 |  |  |  | $ 991,696 |  |  |  | $ 2,928,929 | $ 991,696 |  |  |  |
Secured Debt |  | 0 |  |  |  | 73,993 |  |  |  | 0 | 73,993 |  |  |  |
One Time Interest Payment on Surplus Notes |  |  |  |  |  |  |  |  |  |  |  |  |  | 13,501 |
Junior surplus note of Ambac Assurance Segregated Account |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 350,000
AMPS Exchange Total Surplus Notes Issued |  |  |  |  |  |  |  |  |  |  |  |  | $ 212,740 |  |
Net realized gains on extinguishment of debt |  | 0 | $ 0 | $ 6 | $ 3,115 | 0 | $ 0 | $ 2,179 | $ 2,741 | 3,121 | 4,920 | $ 4,845 |  |  |
5.1% Junior Surplus Notes, General Account Due 2020 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Face Amount |  | $ 366,644 |  |  |  | 370,237 |  |  |  | $ 366,644 | 370,237 |  |  |  |
Ambac Note Post Exit From Rehabilitation [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage |  | 7.60% |  |  |  |  |  |  |  | 7.60% |  |  |  |  |
Paydown of Ambac Note |  |  |  |  |  |  |  |  |  | $ 214,062 |  |  |  |  |
Tier 2 Notes [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 8.50% |  |  |  |  |  |  |  | 8.50% |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage |  | 9.90% |  |  |  |  |  |  |  | 9.90% |  |  |  |  |
Debt Instrument, Face Amount |  | $ 258,585 |  |  |  |  |  |  |  | $ 258,585 |  |  |  |  |
Paid-in-Kind Interest |  |  |  |  |  |  |  |  |  | 18,585 |  |  |  |  |
Secured Debt [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Face Amount |  | $ 0 |  |  |  | 73,993 |  |  |  | $ 0 | 73,993 |  |  |  |
5.1% Surplus Notes, General Account, Due 2020 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage |  | 10.10% |  |  |  |  |  |  |  | 10.10% |  |  |  |  |
Debt Instrument Principal Amount Subject To Repurchase |  |  |  |  |  |  |  |  |  |  |  |  |  | 463,624 |
AMPS Exchange Total Surplus Notes Issued |  |  |  |  |  |  |  |  |  |  |  |  | $ 212,740 |  |
Surplus Notes Other Additional Net Issuance Par |  | $ 26,817 |  |  |  |  |  |  |  | $ 26,817 |  |  |  |  |
Debt Instrument, Repurchased Face Amount |  |  |  |  |  | 147,236 |  |  |  |  | 147,236 |  |  |  |
Net realized gains on extinguishment of debt |  |  |  |  |  |  |  |  |  | 3,121 | 3,815 |  |  |  |
Debt Instrument, Face Amount |  | $ 530,744 |  |  |  | 754,811 |  |  |  | $ 530,744 | 754,811 |  |  |  |
5.1% Junior Surplus Notes, Segregated Account Due 2020 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage |  | 19.50% |  |  |  |  |  |  |  | 19.50% |  |  |  |  |
One State Street [Member] | 5.1% Junior Surplus Notes, Segregated Account Due 2020 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument Principal Amount Subject To Repurchase |  | $ 1,661 |  |  |  |  |  |  |  | $ 1,661 |  |  |  |  |
Debt Instrument, Face Amount |  | $ 16,644 |  |  |  | 20,237 |  |  |  | 16,644 | 20,237 |  |  |  |
Extinguishment of Debt, Amount |  |  |  |  |  |  |  |  |  | $ 3,593 | 3,799 |  |  |  |
Variable Interest Entity, Not Primary Beneficiary, Aggregated Disclosure [Member] | 5.1% Junior Surplus Notes, Segregated Account Due 2020 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage |  | 8.40% |  |  |  |  |  |  |  | 8.40% |  |  |  |  |
Ambac Assurance Corporation [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  | $ 2,928,929 |  |  |  | 991,696 |  |  |  | $ 2,928,929 | 991,696 |  |  |  |
Secured Debt |  | 0 |  |  |  | 73,993 |  |  |  | 0 | 73,993 |  |  |  |
Ambac Assurance Corporation [Member] | 5.1% Junior Surplus Notes, General Account Due 2020 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  | 249,785 |  |  |  | 249,036 |  |  |  | 249,785 | 249,036 |  |  |  |
Ambac Assurance Corporation [Member] | Ambac Note Post Exit From Rehabilitation [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  | 1,940,289 |  |  |  | 0 |  |  |  | 1,940,289 | 0 |  |  |  |
Ambac Assurance Corporation [Member] | Tier 2 Notes [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  | 251,745 |  |  |  | 0 |  |  |  | 251,745 | 0 |  |  |  |
Ambac Assurance Corporation [Member] | 5.1% Surplus Notes, General Account, Due 2020 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  | 487,110 |  |  |  | $ 668,667 |  |  |  | 487,110 | $ 668,667 |  |  |  |
Variable Interest Entities [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  |  |  |  |  | 6.65% |  |  |  |  | 6.65% |  |  |  |
Long-term debt |  | $ 5,268,596 |  |  |  | $ 12,160,544 |  |  |  | $ 5,268,596 | $ 12,160,544 |  |  |  |
5.1% Junior Surplus Notes Due 2020 [Member] | Ambac Assurance Corporation [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 5.10% |  |  |  | 5.10% |  |  |  | 5.10% | 5.10% |  |  |  |
Debt Instruments Maturity Year |  |  |  |  |  |  |  |  |  | 2020 | 2020 |  |  |  |
5.1 % Surplus Notes Due 2020 [Member] | Ambac Assurance Corporation [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  | 5.10% |  |  |  | 5.10% |  |  |  | 5.10% | 5.10% |  |  |  |
Debt Instruments Maturity Year |  |  |  |  |  |  |  |  |  | 2020 | 2020 |  |  |  |
5.1% Surplus Notes, General Account, Due 2020 [Member] | Ambac Assurance Corporation [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  |  |  | 5.10% |  |  |  |  |  |  |  |  |  |  |
Consolidated Variable Interest Entities [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unpaid Principal Amount Of Fixed Rate Debt Accounted For Under Fair Value Option |  |  | $ 4,552,643 |  |  | $ 9,387,884 |  |  |  |  | $ 9,387,884 |  |  |  |
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months |  | $ 255,040 |  |  |  |  |  |  |  | $ 255,040 |  |  |  |  |
Long-term Debt, Maturities, Repayments of Principal in Year Two |  | 0 |  |  |  |  |  |  |  | 0 |  |  |  |  |
Long-term Debt, Maturities, Repayments of Principal in Year Three |  | 0 |  |  |  |  |  |  |  | 0 |  |  |  |  |
Long-term Debt, Maturities, Repayments of Principal in Year Four |  | 0 |  |  |  |  |  |  |  | 0 |  |  |  |  |
Long-term Debt, Maturities, Repayments of Principal in Year Five |  | $ 124,233 |  |  |  |  |  |  |  | $ 124,233 |  |  |  |  |
Consolidated Variable Interest Entities [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage |  | 1.36% |  |  |  | 0.96% |  |  |  | 1.36% | 0.96% |  |  |  |
Consolidated Variable Interest Entities [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage |  | 7.93% |  |  |  | 8.35% |  |  |  | 7.93% | 8.35% |  |  |  |
London Interbank Offered Rate (LIBOR) [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest Rate on Securities Issued by Delaware Trust | 2.80% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest Rate on Ambac Note Post Exit From Rehabilitation |  |  |  |  |  |  |  |  |  | 5.00% |  |  |  |  |
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest Rate on Ambac Note Post Exit From Rehabilitation |  |  |  |  |  |  |  |  |  | 1.00% |  |  |  |  |
Ambac [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
One Time Interest Payment on Surplus Notes |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 2,618 |

X
- Definition AMPS Exchange Total Surplus Notes Issued + References No definition available. + Details
Name: | ambc_AMPSExchangeTotalSurplusNotesIssued
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Junior Surplus Notes issued by the Segregated Account of Ambac Assurance to Ambac upon Ambac's emergence from bankruptcy. These Junior Surplus notes will be includable in surplus for statutory accounting purposes as prescribed or permitted by state laws and regulations. + References No definition available. + Details
Name: | ambc_Ambc_JuniorSurplusNotesIssued
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Debt Instrument Principal Amount Subject To Reduction + References No definition available. + Details
Name: | ambc_DebtInstrumentPrincipalAmountSubjectToReduction
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Debt Instruments Maturity Year + References No definition available. + Details
Name: | ambc_DebtInstrumentsMaturityYear
Namespace Prefix: | ambc_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

X
- Definition Interest Rate on Ambac Note Post Exit From Rehabilitation + References No definition available. + Details
Name: | ambc_InterestRateonAmbacNotePostExitFromRehabilitation
Namespace Prefix: | ambc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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 One Time Interest Payment on Surplus Notes + References No definition available. + Details
Name: | ambc_OneTimeInterestPaymentonSurplusNotes
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Paydown of Ambac Note + References No definition available. + Details
Name: | ambc_PaydownofAmbacNote
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Surplus Notes Other Additional Net Issuance Par + References No definition available. + Details
Name: | ambc_SurplusNotesOtherAdditionalNetIssuancePar
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Tier 2 Note Security in RMBS Litigation Settlement Proceeds + References No definition available. + Details
Name: | ambc_Tier2NoteSecurityinRMBSLitigationSettlementProceeds
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Unpaid Principal Amount Of Fixed Rate Debt Accounted For Under Fair Value Option + References No definition available. + Details
Name: | ambc_UnpaidPrincipalAmountOfFixedRateDebtAccountedForUnderFairValueOption
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6036836-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
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_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of the original debt instrument that was repurchased. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentRepurchasedFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Gross amount of debt extinguished. + References No definition available. + Details
Name: | us-gaap_ExtinguishmentOfDebtAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=114001942&loc=d3e12355-112629 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=114001942&loc=d3e12317-112629 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 + Details
Name: | us-gaap_GainsLossesOnExtinguishmentOfDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -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 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -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 4: http://fasb.org/us-gaap/role/ref/legacyRef -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 + Details
Name: | us-gaap_LongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04.(a)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04.(a)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04.(a)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04.(a)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04.(a)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Interest paid other than in cash for example by issuing additional debt securities. As a noncash item, it is added to net income when calculating cash provided by or used in operations using the indirect method. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 + Details
Name: | us-gaap_PaidInKindInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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://fasb.org/us-gaap/role/ref/legacyRef -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 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -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 3: http://fasb.org/us-gaap/role/ref/legacyRef -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 + Details
Name: | us-gaap_SecuredDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=ambc_A5.1JuniorSurplusNotesGeneralAccountDue2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=ambc_AmbacNotePostExitFromRehabilitationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=ambc_Tier2NotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_SecuredDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=ambc_A5.1SurplusNotesGeneralAccountDue2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=ambc_A5.1JuniorSurplusNotesSegregatedAccountDue2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=ambc_OneStateStreetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=ambc_Ambc_NonconsolidatedVIETrustMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

X
- Details
Name: | us-gaap_DebtInstrumentAxis=ambc_A5.1JuniorSurplusNotesDue2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=ambc_A5.1SurplusNotesDue2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=ambc_A5.1SurplusNotesGeneralAccountDue2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=ambc_AmbacMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |