XML 80 R24.htm IDEA: XBRL DOCUMENT
v3.20.1

Financial Guarantee Insurance Contracts (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2020
Insurance [Line Items] |
Schedule of Loss And Loss Expense Reserves And Subrogation Recoverable Table [Table Text Block] | Below are the components of the loss reserves liability and the Subrogation recoverable asset at March 31, 2020 and December 31, 2019:
|  | March 31, 2020: |  | December 31, 2019:
|  | Present Value of Expected Net Cash Flows |  | Unearned Premium Revenue |  | Gross Loss and Loss Expense Reserves |  | Present Value of Expected Net Cash Flows |  | Unearned Premium Revenue |  | Gross Loss and Loss Expense Reserves
Balance Sheet Line Item |  | Claims and Loss Expenses |  | Recoveries |  |  |  | Claims and Loss Expenses |  | Recoveries |  |
Loss and loss expense reserves |  | $ | 2,112 |  |  | $ | (245 | ) |  | $ | (70 | ) |  | $ | 1,797 |  |  | $ | 1,835 |  |  | $ | (233 | ) |  | $ | (54 | ) |  | $ | 1,548 |
Subrogation recoverable |  | 135 |  |  | (2,327 | ) |  | — |  |  | (2,192 | ) |  | 131 |  |  | (2,160 | ) |  | — |  |  | (2,029 | )
Totals |  | $ | 2,247 |  |  | $ | (2,572 | ) |  | $ | (70 | ) |  | $ | (395 | ) |  | $ | 1,966 |  |  | $ | (2,394 | ) |  | $ | (54 | ) |  | $ | (482 | )
Summary of Gross Premium Receivable Roll-Forward (Direct and Assumed Contracts) | Below is the gross premium receivable roll-forward for the respective periods, net of allowance for credit losses:
|  | Three Months Ended March 31,
|  | 2020 |  | 2019
Beginning premium receivable |  | $ | 416 |  |  | $ | 495 |
Adjustment to initially apply ASU 2016-13 |  | (3 | ) |  | — |
Premium receipts |  | (12 | ) |  | (13 | )
Adjustments for changes in expected and contractual cash flows (1) |  | 10 |  |  | — |
Accretion of premium receivable discount |  | 2 |  |  | 3 |
Changes to allowance for credit losses |  | (2 | ) |  | — |
Other adjustments (including foreign exchange) |  | (8 | ) |  | 2 |
Ending premium receivable (2) |  | $ | 403 |  |  | $ | 487 |
(1) | Adjustments for changes in expected and contractual cash flows primarily due to changes in indexation rates on certain UK transactions partially offset by reductions in insured exposure as a result of early policy terminations and unscheduled principal paydowns.
(2) Premium receivable includes premiums to be received in foreign denominated currencies most notably in British Pounds and Euros. At March 31, 2020 and 2019, premium receivables include British Pounds of $128 (£103) and $142 (£109), respectively, and Euros of $24 (€22) and $30 (€27), respectively.
Effect of Reinsurance on Premiums Written and Earned | The effect of reinsurance on premiums written and earned for the respective periods was as follows:
| Three Months Ended March 31,
| 2020 |  | 2019
| Written |  | Earned |  | Written |  | Earned
Direct | $ | 11 |  |  | $ | 13 |  |  | $ | 3 |  |  | $ | 29 |
Assumed | — |  |  | 1 |  |  | — |  |  | — |
Ceded | (1 | ) |  | 3 |  |  | (1 | ) |  | 2 |
Net premiums | $ | 12 |  |  | $ | 10 |  |  | $ | 4 |  |  | $ | 28 |
Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Table Text Block] | The following table summarizes net premiums earned by location of risk for the respective periods:
| Three Months Ended March 31,
| 2020 |  | 2019
United States | $ | 7 |  |  | $ | 28 |
United Kingdom | 4 |  |  | 4 |
Other international | — |  |  | (5 | )
Total | $ | 10 |  |  | $ | 28 |
Summarized Future Gross Undiscounted Premiums Expected to be Collected and Future Expected Premiums Earned, Net of Reinsurance | The table below summarizes the future gross undiscounted premiums to be collected and future premiums earned, net of reinsurance at March 31, 2020:
| Future Premiums to be Collected (1) |  | Future Premiums to be Earned Net of Reinsurance (2)
Three months ended: |  |  |
June 30, 2020 | $ | 12 |  |  | $ | 10 |
September 30, 2020 | 10 |  |  | 10 |
December 31, 2020 | 10 |  |  | 10 |
Twelve months ended: |  |  |
December 31, 2021 | 37 |  |  | 36 |
December 31, 2022 | 35 |  |  | 34 |
December 31, 2023 | 34 |  |  | 32 |
December 31, 2024 | 32 |  |  | 30 |
Five years ended: |  |  |
December 31, 2029 | 142 |  |  | 125 |
December 31, 2034 | 104 |  |  | 83 |
December 31, 2039 | 52 |  |  | 38 |
December 31, 2044 | 23 |  |  | 14 |
December 31, 2049 | 9 |  |  | 5 |
December 31, 2054 | 1 |  |  | 1 |
Total | $ | 501 |  |  | $ | 428 |
(1) | Future premiums to be collected are undiscounted, gross of allowance for credit losses, and are used to derive the discounted premium receivable asset recorded on Ambac's balance sheet.
(2) Future premiums to be earned, net of reinsurance relate to the unearned premiums liability and deferred ceded premium asset recorded on Ambac’s balance sheet. The use of contractual lives for many bond types which do not have homogeneous pools of underlying collateral is required in the calculation of the premium receivable, as further described in Note 2. Basis of Presentation and Significant Accounting Policies in the Notes to Consolidated Financial Statements included in Ambac's Annual Report on Form 10-K for the year ended December 31, 2019. This results in a different premium receivable balance than if expected lives were considered. If installment paying policies are retired or prepay early, premiums reflected in the premium receivable asset and amounts reported in the above table for such policies may not be collected. Future premiums to be earned also considers the use of contractual lives for many bond types which do not have homogeneous pools of underlying collateral, which may result in different unearned premium than if expected lives were considered. If those bonds types are retired early, premium earnings may be negative in the period of call or refinancing
Premium Receivable, Allowance for Credit Loss [Table Text Block] | Below is a rollforward of the premium receivable allowance for credit losses as of March 31, 2020:
Beginning balance (1) |  | $ | 9 |
Current period provision (2) |  | 5 |
Write-offs of the allowance |  | — |
Recoveries of previously written-off amounts |  | — |
Ending balance |  | $ | 14 |
(1) | At December 31, 2019, $9 of premiums receivable were deemed uncollectible as determined under prior GAAP rules.
(2) Includes $3 from the adoption of ASU 2016-13 on January 1, 2020.
Summary of Loss Reserve Roll-Forward, Net of Subrogation Recoverable and Reinsurance | Below is the loss reserves roll-forward, net of subrogation recoverable and reinsurance, for the affected periods:
| Three Months Ended March 31,
| 2020 |  | 2019
Beginning gross loss and loss expense reserves | $ | (482 | ) |  | $ | (107 | )
Reinsurance recoverable | 26 |  |  | 23 |
Beginning balance of net loss and loss expense reserves | (508 | ) |  | (130 | )
Losses and loss expenses (benefit): |  |  |
Current year | 27 |  |  | 1 |
Prior years | 90 |  |  | 12 |
Total (1) (2) | 117 |  |  | 12 |
Loss and loss expenses paid (recovered): |  |  |
Current year | — |  |  | — |
Prior years | 39 |  |  | 64 |
Total | 39 |  |  | 64 |
Foreign exchange effect | — |  |  | 6 |
Ending net loss and loss expense reserves | (430 | ) |  | (176 | )
Impact of VIE consolidation | — |  |  | (72 | )
Reinsurance recoverable (3) | 35 |  |  | 26 |
Ending gross loss and loss expense reserves | $ | (395 | ) |  | $ | (222 | )
(1) | Total losses and loss expenses (benefit) includes $(10) and $(5) for the three months ended March 31, 2020 and 2019, respectively, related to ceded reinsurance.
(2) | Ambac records the impact of estimated recoveries related to securitized loans in RMBS transactions that breached certain representations and warranties ("R&W"s) by transaction sponsors within losses and loss expenses (benefit). The losses and loss expense (benefit) incurred associated with changes in estimated R&Ws for the three months ended March 31, 2020 and 2019 was $(36) and $4, respectively.
(3) Represents reinsurance recoverable on future loss and loss expenses. Additionally, the Balance Sheet line "Reinsurance recoverable on paid and unpaid losses" includes reinsurance recoverables (payables) of $1 and $1 as of March 31, 2020 and 2019, respectively, related to previously presented loss and loss expenses and subrogation.
Summary of Information Related to Policies Currently Included in Ambac's Loss Reserves or Subrogation Recoverable | The tables below summarize information related to policies currently included in Ambac’s loss reserves or subrogation recoverable at March 31, 2020 and December 31, 2019. Gross par exposures include capital appreciation bonds which are reported at the par amount at the time of issuance of the insurance policy as opposed to the current accreted value of the bond. The weighted average risk-free rate used to discount loss reserves at March 31, 2020 and December 31, 2019 was 0.9% and 2.1%, respectively.
Surveillance Categories as of March 31, 2020
| I |  | IA |  | II |  | III |  | IV |  | V |  | Total
Number of policies | 33 |  |  | 22 |  |  | 14 |  |  | 16 |  |  | 136 |  |  | 3 |  |  | 224 |
Remaining weighted-average contract period (in years) (1) | 24 |  |  | 21 |  |  | 9 |  |  | 17 |  |  | 15 |  |  | 2 |  |  | 15 |
Gross insured contractual payments outstanding: |  |  |  |  |  |  |  |  |  |  |  |  |
Principal | $ | 727 |  |  | $ | 483 |  |  | $ | 607 |  |  | $ | 1,524 |  |  | $ | 3,667 |  |  | $ | 37 |  |  | $ | 7,046 |
Interest | 394 |  |  | 507 |  |  | 512 |  |  | 326 |  |  | 1,608 |  |  | 11 |  |  | 3,358 |
Total | $ | 1,121 |  |  | $ | 991 |  |  | $ | 1,119 |  |  | $ | 1,850 |  |  | $ | 5,275 |  |  | $ | 48 |  |  | $ | 10,404 |
Gross undiscounted claim liability | $ | 18 |  |  | $ | 44 |  |  | $ | 41 |  |  | $ | 521 |  |  | $ | 1,778 |  |  | $ | 48 |  |  | $ | 2,450 |
Discount, gross claim liability | (1 | ) |  | (2 | ) |  | (1 | ) |  | (71 | ) |  | (184 | ) |  | — |  |  | (259 | )
Gross claim liability before all subrogation and before reinsurance | 17 |  |  | 42 |  |  | 41 |  |  | 450 |  |  | 1,594 |  |  | 47 |  |  | 2,191 |
Less: |  |  |  |  |  |  |  |  |  |  |  |  |
Gross RMBS subrogation (2) | — |  |  | — |  |  | — |  |  | — |  |  | (1,771 | ) |  | — |  |  | (1,771 | )
Discount, RMBS subrogation | — |  |  | — |  |  | — |  |  | — |  |  | 7 |  |  | — |  |  | 7 |
Discounted RMBS subrogation, before reinsurance | — |  |  | — |  |  | — |  |  | — |  |  | (1,764 | ) |  | — |  |  | (1,764 | )
Less: |  |  |  |  |  |  |  |  |  |  |  |  |
Gross other subrogation (3) | — |  |  | — |  |  | — |  |  | (39 | ) |  | (777 | ) |  | (13 | ) |  | (829 | )
Discount, other subrogation | — |  |  | — |  |  | — |  |  | 1 |  |  | 18 |  |  | 1 |  |  | 21 |
Discounted other subrogation, before reinsurance | — |  |  | — |  |  | — |  |  | (38 | ) |  | (759 | ) |  | (11 | ) |  | (809 | )
Gross claim liability, net of all subrogation and discounts, before reinsurance | 17 |  |  | 42 |  |  | 41 |  |  | 412 |  |  | (929 | ) |  | 36 |  |  | (381 | )
Less: Unearned premium revenue | (2 | ) |  | (9 | ) |  | (5 | ) |  | (19 | ) |  | (34 | ) |  | — |  |  | (70 | )
Plus: Loss expense reserves | — |  |  | 1 |  |  | 1 |  |  | 4 |  |  | 50 |  |  | — |  |  | 55 |
Gross loss and loss expense reserves | $ | 15 |  |  | $ | 34 |  |  | $ | 36 |  |  | $ | 397 |  |  | $ | (914 | ) |  | $ | 36 |  |  | $ | (395 | )
Reinsurance recoverable reported on Balance Sheet (4) | $ | — |  |  | $ | 6 |  |  | $ | 9 |  |  | $ | 27 |  |  | $ | (7 | ) |  | $ | — |  |  | $ | 36 |
(1) | Remaining weighted-average contract period is weighted based on projected gross claims over the lives of the respective policies.
(2) | RMBS subrogation represents Ambac’s estimate of subrogation recoveries from RMBS transaction sponsors for R&W breaches.
(3) | Other subrogation represents subrogation related to excess spread and other contractual cash flows on public finance and structured finance transactions, including RMBS.
(4) | Reinsurance recoverable reported on the Balance Sheet includes reinsurance recoverables of $35 related to future loss and loss expenses and $1 related to presented loss and loss expenses and subrogation.
Surveillance Categories as of December 31, 2019
| I |  | IA |  | II |  | III |  | IV |  | V |  | Total
Number of policies | 34 |  |  | 18 |  |  | 11 |  |  | 16 |  |  | 139 |  |  | 3 |  |  | 221 |
Remaining weighted-average contract period (in years) (1) | 8 |  |  | 21 |  |  | 9 |  |  | 17 |  |  | 14 |  |  | 3 |  |  | 15 |
Gross insured contractual payments outstanding: |  |  |  |  |  |  |  |  |  |  |  |  |
Principal | $ | 668 |  |  | $ | 510 |  |  | $ | 277 |  |  | $ | 857 |  |  | $ | 3,819 |  |  | $ | 37 |  |  | $ | 6,168 |
Interest | 340 |  |  | 507 |  |  | 128 |  |  | 366 |  |  | 1,678 |  |  | 11 |  |  | 3,029 |
Total | $ | 1,007 |  |  | $ | 1,016 |  |  | $ | 404 |  |  | $ | 1,223 |  |  | $ | 5,498 |  |  | $ | 48 |  |  | $ | 9,197 |
Gross undiscounted claim liability | $ | 2 |  |  | $ | 44 |  |  | $ | 21 |  |  | $ | 541 |  |  | $ | 1,778 |  |  | $ | 48 |  |  | $ | 2,434 |
Discount, gross claim liability | — |  |  | (5 | ) |  | (1 | ) |  | (152 | ) |  | (381 | ) |  | (2 | ) |  | (541 | )
Gross claim liability before all subrogation and before reinsurance | 2 |  |  | 39 |  |  | 20 |  |  | 389 |  |  | 1,397 |  |  | 46 |  |  | 1,893 |
Less: |  |  |  |  |  |  |  |  |  |  |  |  |
Gross RMBS subrogation (2) | — |  |  | — |  |  | — |  |  | — |  |  | (1,777 | ) |  | — |  |  | (1,777 | )
Discount, RMBS subrogation | — |  |  | — |  |  | — |  |  | — |  |  | 49 |  |  | — |  |  | 49 |
Discounted RMBS subrogation, before reinsurance | — |  |  | — |  |  | — |  |  | — |  |  | (1,727 | ) |  | — |  |  | (1,727 | )
Less: |  |  |  |  |  |  |  |  |  |  |  |  |
Gross other subrogation (3) | — |  |  | — |  |  | — |  |  | (41 | ) |  | (666 | ) |  | (13 | ) |  | (720 | )
Discount, other subrogation | — |  |  | — |  |  | — |  |  | 4 |  |  | 47 |  |  | 3 |  |  | 53 |
Discounted other subrogation, before reinsurance | — |  |  | — |  |  | — |  |  | (37 | ) |  | (620 | ) |  | (10 | ) |  | (666 | )
Gross claim liability, net of all subrogation and discounts, before reinsurance | 2 |  |  | 39 |  |  | 20 |  |  | 353 |  |  | (950 | ) |  | 36 |  |  | (501 | )
Less: Unearned premium revenue | (1 | ) |  | (9 | ) |  | (1 | ) |  | (7 | ) |  | (35 | ) |  | — |  |  | (54 | )
Plus: Loss expense reserves | 1 |  |  | 1 |  |  | 1 |  |  | 4 |  |  | 67 |  |  | — |  |  | 73 |
Gross loss and loss expense reserves | $ | 1 |  |  | $ | 30 |  |  | $ | 20 |  |  | $ | 349 |  |  | $ | (918 | ) |  | $ | 36 |  |  | $ | (482 | )
Reinsurance recoverable reported on Balance Sheet (4) | $ | — |  |  | $ | 6 |  |  | $ | 7 |  |  | $ | 24 |  |  | $ | (10 | ) |  | $ | — |  |  | $ | 26 |
(1) | Remaining weighted-average contract period is weighted based on projected gross claims over the lives of the respective policies.
(2) | RMBS subrogation represents Ambac’s estimate of subrogation recoveries from RMBS transaction sponsors for R&W breaches.
(3) | Other subrogation represents subrogation related to excess spread and other contractual cash flows on public finance and structured finance transactions, including RMBS.
(4) Reinsurance recoverable reported on Balance Sheet includes reinsurance recoverables of $26 related to future loss and loss expenses and $0 related to presented loss and loss expenses and subrogation.
Summary of Rollforward of RMBS Subrogation, by Estimation Approach | Below is the rollforward of R&W subrogation for the affected periods:
| Three Months Ended March 31,
| 2020 |  | 2019
Discounted R&W subrogation (gross of reinsurance) at beginning of period | $ | 1,727 |  |  | $ | 1,771 |
All other changes (1) | 36 |  |  | (43 | )
Discounted R&W subrogation (gross of reinsurance) at end of period | $ | 1,764 |  |  | $ | 1,727 |
(1) | All other changes which may impact RMBS R&W subrogation recoveries include changes in actual or projected collateral
performance, changes in the creditworthiness of a sponsor and/or the projected timing of recoveries.
Insurance Intangible Asset [Member] |
Insurance [Line Items] |
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] | The estimated future amortization expense for the net insurance intangible asset is as follows:
Amortization expense (1) (2) |  |
2020 (nine months) |  | $ | 33 |
2021 |  | 39 |
2022 |  | 35 |
2023 |  | 32 |
2024 |  | 29 |
Thereafter |  | 239 |
(1) | The insurance intangible asset will be amortized using a level-yield method based on par exposure of the related financial guarantee insurance or reinsurance contracts. Future amortization considers the use of contractual lives for many bond types which do not have homogeneous pools of underlying collateral. Actual maturities will differ from contractual maturities because borrowers may have the right to call or prepay certain obligations. If those bonds types are retired early, amortization expense may differ in the period of call or refinancing.
(2) The weighted-average amortizations period is 7.6 years.

X
- Definition Financial guarantee insurance contracts premium receivable activity. + References No definition available. + Details
Name: | ambc_FinancialGuaranteeInsuranceContractsPremiumReceivableActivityTableTextBlock
Namespace Prefix: | ambc_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Financial guarantee insurance contracts premium receivable premium expected to be collected and future expected premiums to be earned, net of reinsurance. + References No definition available. + Details
Name: | ambc_FinancialGuaranteeInsuranceContractsPremiumReceivablePremiumExpectedToBeCollectedAndFutureExpectedPremiumsEarnedTableTextBlock
Namespace Prefix: | ambc_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Insurance [Line Items] + References No definition available. + Details
Name: | ambc_InsuranceLineItems
Namespace Prefix: | ambc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule Of Reinsurance On Premiums Written And Earned Table [Text Block] + References No definition available. + Details
Name: | ambc_ScheduleOfReinsuranceOnPremiumsWrittenAndEarnedTableTextBlock
Namespace Prefix: | ambc_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure that provides regarding the balance sheet line items for the liability "Loss and Loss Expense Reserves" and the asset "Subrogation Recoverable". Includes the various components of Unpaid Claims, Accrued Interest on Unpaid Claims, Present Value of Future Expected Claims and Loss Expenses, Present Vlaue of Future Expected Recoveries and the related Unearned Premium Revenue liability. + References No definition available. + Details
Name: | ambc_ScheduleofLossAndLossExpenseReservesAndSubrogationRecoverableTableTableTextBlock
Namespace Prefix: | ambc_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular presentation of rollforward of RMBS subrogation, by estimation approach. + References No definition available. + Details
Name: | ambc_SummaryOfBalanceOfRmbsSubrogationRecoveriesByEstimationApproachTableTextBlock
Namespace Prefix: | ambc_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of allowance for credit loss on premium receivable. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447 + Details
Name: | us-gaap_PremiumReceivableAllowanceForCreditLossTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of insured financial obligations with credit deterioration related to the claim liability on financial guarantee insurance contracts as of the end of each annual and interim reporting period detailing, at a minimum, the following for each surveillance category or grouping used to track and monitor the entity's insured financial obligations: (1) number of issued and outstanding financial guarantee insurance contracts; (2) remaining weighted average contract period; (3) insured contractual payments outstanding, segregating principal and interest; (4) gross claim liability; (5) gross potential recoveries; (6) net discount of both the claim liability and potential recoveries; (7) net claim liability; (8) reinsurance recoverable; and (9) unearned premium revenue. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 55 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=99379334&loc=SL5751140-161288 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 9 -Subparagraph (a)(5), (b)(1) -URI http://asc.fasb.org/extlink&oid=99382878&loc=SL5749324-161292 + Details
Name: | us-gaap_ScheduleOfInsuredFinancialObligationsWithCreditDeteriorationTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the activity in the reserve for settling insured claims and expenses incurred in the claims settlement process for the period. The estimated liability includes the amount of money that will be required for future payments of (a) claims that have been reported to the insurer, (b) claims related to insured events that have occurred but that have not been reported to the insurer as of the date the liability is estimated, and (c) claim adjustment expenses. Claim adjustment expenses include costs incurred in the claim settlement process such as legal fees; outside adjuster fees; and costs to record, process, and adjust claims. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=116884095&loc=d3e14764-158437 + Details
Name: | us-gaap_ScheduleOfLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the names of foreign countries from which revenue is material and the amount of revenue from external customers attributed to those countries. An entity may also provide subtotals of geographic information about groups of countries. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 41 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e9038-108599 + Details
Name: | us-gaap_ScheduleOfRevenueFromExternalCustomersAttributedToForeignCountriesByGeographicAreaTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the amount of amortization expense expected to be recorded in succeeding fiscal years for finite-lived intangible assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 + Details
Name: | us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=ambc_InsuranceIntangibleAssetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |