XML 82 R62.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Financial Guarantee Insurance Contracts - Summary of Gross Premium Receivable Roll-Forward (Direct and Assumed Contracts) (Detail) € in Thousands, £ in Thousands, $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2018 USD ($) | Dec. 31, 2018 EUR (€) | Dec. 31, 2018 GBP (£) | Dec. 31, 2017 USD ($) | Dec. 31, 2017 EUR (€) | Dec. 31, 2017 GBP (£) | Dec. 31, 2016 USD ($)
Insurance [Line Items] |  |  |  |  |  |  |
Premiums Receivable, Allowance for Doubtful Accounts | $ 7,136 |  |  | $ 9,331 |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |
Beginning premium receivable | 586,312 |  |  | 661,337 |  |  | $ 831,575
Premium receipts | 56,441 |  |  | 81,597 |  |  | (77,038)
Adjustments for changes in expected and contractual cash flows | (41,762) |  |  | (30,334) |  |  | (78,528)
Accretion of premium receivable discount | 14,668 |  |  | 16,162 |  |  | 18,637
Uncollectable premiums | 2,167 |  |  | (141) |  |  | 6,054
Other adjustments (including foreign exchange) | (9,553) |  |  | 20,885 |  |  | (39,363)
Ending premium receivable | 495,391 |  |  | 586,312 |  |  | 661,337
United Kingdom, Pounds |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |
Beginning premium receivable | 151,852 |  | £ 112,342 | 177,878 |  | £ 144,393 |
Ending premium receivable | 131,458 |  | £ 103,088 | 151,852 |  | £ 112,342 | 177,878
Euro Member Countries, Euro |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |
Beginning premium receivable | 36,001 | € 29,976 |  | 34,866 | € 33,108 |  |
Ending premium receivable | $ 30,597 | € 26,708 |  | $ 36,001 | € 29,976 |  | $ 34,866
External Credit Rating, Non Investment Grade [Member] |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable Percent | 20.00% | 20.00% | 20.00% | 22.00% | 22.00% | 22.00% |

X
- Definition Financial Guarantee Insurance Contracts, Premium Receivable Percent + References No definition available. + Details
Name: | ambc_FinancialGuaranteeInsuranceContractsPremiumReceivablePercent
Namespace Prefix: | ambc_
Data Type: | num:percentItemType
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 Amount of increase (decrease) in the allowance for doubtful accounts. + References No definition available. + Details
Name: | us-gaap_AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of the premium receivable for financial guarantee insurance contracts reported in the statement of financial position. This element primarily would consist of those financial guarantee insurance contracts which premiums are to be collected over the contract period, but may, on occasion, include premiums which are to be collected in full at inception, but which straddle a financial reporting period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 310 -Section 50 -Paragraph 3 -Subparagraph (c)(1),(5) -URI http://asc.fasb.org/extlink&oid=6933075&loc=SL5748726-161290 + Details
Name: | us-gaap_FinancialGuaranteeInsuranceContractsPremiumReceivable
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of cash inflow from premiums received for premium receivable on financial guarantee insurance contracts. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 17 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3367-108585 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 310 -Section 50 -Paragraph 3 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=6933075&loc=SL5748726-161290 + Details
Name: | us-gaap_FinancialGuaranteeInsuranceContractsPremiumReceivableProceedsFromPremiumsReceived
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_FinancialGuaranteeInsuranceContractsPremiumReceivableRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of accretion of the discount for premiums receivable on financial guarantee insurance contracts. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 310 -Section 50 -Paragraph 3 -Subparagraph (c)(4)(iii) -URI http://asc.fasb.org/extlink&oid=6933075&loc=SL5748726-161290 + Details
Name: | us-gaap_FinancialGuaranteeInsuranceContractsPremiumsReceivableAccretionOfDiscountOnPremiumReceivable
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of increase (decrease) in the premium receivable on financial guarantee insurance contracts from changes in the period of the contract. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 310 -Section 50 -Paragraph 3 -Subparagraph (c)(4)(i) -URI http://asc.fasb.org/extlink&oid=6933075&loc=SL5748726-161290 + Details
Name: | us-gaap_FinancialGuaranteeInsuranceContractsPremiumsReceivableAdjustmentChangeInPeriodOfContract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of increase (decrease) in the premiums receivable on financial guarantee insurance contracts from adjustments classified as other. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 310 -Section 50 -Paragraph 3 -Subparagraph (c)(4)(iv) -URI http://asc.fasb.org/extlink&oid=6933075&loc=SL5748726-161290 + Details
Name: | us-gaap_FinancialGuaranteeInsuranceContractsPremiumsReceivableAdjustmentOtherAdjustments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The carrying value as of the balance sheet date of the estimated valuation allowance to reduce gross premiums receivable to net realizable value. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(5)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524 + Details
Name: | us-gaap_PremiumsReceivableAllowanceForDoubtfulAccounts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | srt_CurrencyAxis=currency_GBP
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_EUR
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ExternalCreditRatingByGroupingAxis=us-gaap_ExternalCreditRatingNonInvestmentGradeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |