Financial Guarantee Insurance Contracts, Premium Receivable, Deconsolidation of VIE

No definition available.

Name:	ambc_FinancialGuaranteeInsuranceContractsPremiumReceivableDeconsolidationofVIE
Namespace Prefix:	ambc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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

- Definition

The valuation allowance as of the balance sheet date to reduce the gross amount of receivables to estimated net realizable value, which would be presented in parentheses on the face of the balance sheet.

+ References

Reference 1: 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=123577603&loc=d3e5074-111524

+ Details

Name:	us-gaap_AllowanceForDoubtfulAccountsPremiumsAndOtherReceivables
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of increase (decrease) in allowance for credit loss on accounts receivable.

+ References

+ Details

Name:	us-gaap_AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- 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

- 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=123570139&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

- 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

- 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

- 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

- 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

- Definition

Amount of expense (reversal of expense) for expected credit loss on premium receivable.

+ References

+ Details

Name:	us-gaap_PremiumReceivableCreditLossExpenseReversal
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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/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=120400017&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447

Reference 4: 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=123577603&loc=SL6953423-111524

Reference 5: 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=123577603&loc=d3e5074-111524

+ Details

Name:	us-gaap_PremiumsReceivableAllowanceForDoubtfulAccounts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of writeoff of premium receivable, charged against allowance for credit loss.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524

+ Details

Name:	us-gaap_PremiumsReceivableAllowanceForDoubtfulAccountsWriteOffsAgainstAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Gross amount, as of the balance sheet date, due the entity from (a) agents and insureds, (b) uncollected premiums and (c) others, before deducting the allowance for doubtful accounts.

+ 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 210.7-03.5)
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

Name:	us-gaap_PremiumsReceivableGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 45
-Paragraph 24
-URI http://asc.fasb.org/extlink&oid=124436220&loc=d3e21930-107793

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 45
-Paragraph 23
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124436220&loc=d3e21914-107793

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22644-107794

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=124431353&loc=SL124442411-227067

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 10
-Section 65
-Paragraph 4
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 105
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=124434974&loc=SL124442142-165695

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 105
-SubTopic 10
-Section 65
-Paragraph 6
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=124434974&loc=SL124442142-165695

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=123454820&loc=SL4568740-111683

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 65
-Paragraph 1
-Subparagraph (e)(3)
-URI http://asc.fasb.org/extlink&oid=123482062&loc=SL123482106-238011

Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 45
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124436220&loc=d3e21711-107793

Reference 13: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Reference 14: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6450520&loc=d3e32583-110901

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 65
-Paragraph 8
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=123459177&loc=SL121830611-158277

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section 45
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=118261656&loc=d3e32136-110900

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 65
-Paragraph 8
-Subparagraph (d)(3)
-URI http://asc.fasb.org/extlink&oid=123459177&loc=SL121830611-158277

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (f)(2)
-URI http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 65
-Paragraph 15
-Subparagraph (f)(2)
-URI http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333

Reference 21: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
-Paragraph 4I
-URI http://asc.fasb.org/extlink&oid=120409616&loc=SL4590271-111686

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (f)(1)
-URI http://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section 45
-Paragraph 20
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118261656&loc=d3e32211-110900

Reference 24: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=123454820&loc=SL4568447-111683

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 65
-Paragraph 15
-Subparagraph (f)(1)
-URI http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 65
-Paragraph 15
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=121322162&loc=SL121327923-165333

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Publisher FASB
-Subparagraph (a)(3)(iii)(03)

+ Details

Name:	us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_NoncashOrPartNoncashDivestituresByUniqueNameAxis=ambc_EverspanGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfInsuredFinancialObligationsWithCreditDeteriorationBySurveillanceCategoryAxis=ambc_SurveillanceCategoryOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfInsuredFinancialObligationsWithCreditDeteriorationBySurveillanceCategoryAxis=ambc_SurveillanceCategoryOneaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfInsuredFinancialObligationsWithCreditDeteriorationBySurveillanceCategoryAxis=ambc_SurveillanceCategoryTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfInsuredFinancialObligationsWithCreditDeteriorationBySurveillanceCategoryAxis=ambc_SurveillanceCategoryThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfInsuredFinancialObligationsWithCreditDeteriorationBySurveillanceCategoryAxis=ambc_SurveillanceCategoryFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_PremiumsReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis=us-gaap_AccountingStandardsUpdate201613Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CurrencyAxis=currency_GBP
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CurrencyAxis=currency_EUR
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_UnderlyingAssetClassAxis=us-gaap_StructuredFinanceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SecuritiesFinancingTransactionAxis=ambc_MortgageBackedAndHomeEquityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SecuritiesFinancingTransactionAxis=ambc_StudentLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SecuritiesFinancingTransactionAxis=ambc_StructuredInsuranceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SecuritiesFinancingTransactionAxis=ambc_OtherStructuredFinanceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_UnderlyingAssetClassAxis=ambc_PublicFinanceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SecuritiesFinancingTransactionAxis=ambc_HousingRevenueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SecuritiesFinancingTransactionAxis=ambc_OtherPublicFinanceSectorsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_UnderlyingAssetClassAxis=ambc_InternationalFinanceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SecuritiesFinancingTransactionAxis=ambc_SovereignAndSubSovereignMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SecuritiesFinancingTransactionAxis=ambc_InvestorOwnedAndPublicUtilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SecuritiesFinancingTransactionAxis=ambc_OtherInternationalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Financial Guarantee Insurance Contracts - Summary of Gross Premium Receivable Roll-Forward (Direct and Assumed Contracts) (Detail) $ in Thousands, € in Millions, £ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2021 GBP (£)	Dec. 31, 2021 EUR (€)	Dec. 31, 2020 USD ($)	Dec. 31, 2020 GBP (£)	Dec. 31, 2020 EUR (€)	Dec. 31, 2019 USD ($)	Jan. 01, 2020 USD ($)	Dec. 31, 2018 USD ($)
Insurance [Line Items]
Premium Receivable, Allowance for Credit Loss	$ 9,000			$ 17,000
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Beginning premium receivable	370,000			416,000			$ 495,000
Premium receipts	35,000			46,000			(48,000)
Adjustments for changes in expected and contractual cash flows	(27,000)			(6,000)			(38,000)
Accretion of premium receivable discount	8,000			9,000			11,000
Financial Guarantee Insurance Contracts, Premium Receivable, Deconsolidation of VIE	0			0			3,000
Uncollectable premiums	8,000			(4,000)			(2,000)
Other adjustments (including foreign exchange)	(4,000)			5,000			(6,000)
Ending premium receivable	320,000			370,000			416,000
Allowance for Doubtful Accounts, Premiums and Other Receivables	9,000			17,000			9,000
Premium Receivable, Credit Loss Expense (Reversal)	(6,000)			9,000
Premium Receivable, Allowance for Credit Loss, Writeoff	(2,000)			(2,000)
Premiums Receivable, Gross	329,000			387,000
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,098,000			1,140,000			1,536,000		$ 1,633,000
Everspan Group
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	2,000
Surveillance Category One [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	277,000			302,000
IA [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	12,000			40,000
II [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	6,000			3,000
III [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	22,000			27,000
IV [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	12,000			15,000
Premiums Receivable [Member] \| Accounting Standards Update 2016-13 [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest								$ (3,000)
United Kingdom, Pounds
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Beginning premium receivable	117,000	£ 86		129,000	£ 97
Ending premium receivable	108,000	£ 80		117,000	£ 86		129,000
Euro Member Countries, Euro
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Beginning premium receivable	19,000		€ 16	26,000		€ 23
Ending premium receivable	16,000		€ 14	19,000		€ 16	$ 26,000
Structured Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	45,000			59,000
Structured Finance [Member] \| Mortgage-backed and Home Equity [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	16,000			22,000
Structured Finance [Member] \| Student Loan [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	12,000			16,000
Structured Finance [Member] \| Structured Insurance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	10,000			14,000
Structured Finance [Member] \| Other Structured Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	7,000			7,000
Structured Finance [Member] \| Surveillance Category One [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	19,000			27,000
Structured Finance [Member] \| Surveillance Category One [Member] \| Mortgage-backed and Home Equity [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	1,000			3,000
Structured Finance [Member] \| Surveillance Category One [Member] \| Student Loan [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	1,000			3,000
Structured Finance [Member] \| Surveillance Category One [Member] \| Structured Insurance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	10,000			14,000
Structured Finance [Member] \| Surveillance Category One [Member] \| Other Structured Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	7,000			7,000
Structured Finance [Member] \| IA [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	1,000			0
Structured Finance [Member] \| IA [Member] \| Mortgage-backed and Home Equity [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| IA [Member] \| Student Loan [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	1,000			0
Structured Finance [Member] \| IA [Member] \| Structured Insurance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| IA [Member] \| Other Structured Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| II [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	1,000			3,000
Structured Finance [Member] \| II [Member] \| Mortgage-backed and Home Equity [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	1,000			1,000
Structured Finance [Member] \| II [Member] \| Student Loan [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			2,000
Structured Finance [Member] \| II [Member] \| Structured Insurance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| II [Member] \| Other Structured Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| III [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	12,000			14,000
Structured Finance [Member] \| III [Member] \| Mortgage-backed and Home Equity [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	2,000			3,000
Structured Finance [Member] \| III [Member] \| Student Loan [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	9,000			11,000
Structured Finance [Member] \| III [Member] \| Structured Insurance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| III [Member] \| Other Structured Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| IV [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	12,000			15,000
Structured Finance [Member] \| IV [Member] \| Mortgage-backed and Home Equity [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	12,000			15,000
Structured Finance [Member] \| IV [Member] \| Student Loan [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| IV [Member] \| Structured Insurance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| IV [Member] \| Other Structured Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Public Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	159,000			185,000
Public Finance [Member] \| Housing Revenue [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	157,000			168,000
Public Finance [Member] \| Other Public Finance Sectors [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	2,000			17,000
Public Finance [Member] \| Surveillance Category One [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	151,000			157,000
Public Finance [Member] \| Surveillance Category One [Member] \| Housing Revenue [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	149,000			155,000
Public Finance [Member] \| Surveillance Category One [Member] \| Other Public Finance Sectors [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	2,000			2,000
Public Finance [Member] \| IA [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	3,000			27,000
Public Finance [Member] \| IA [Member] \| Housing Revenue [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	3,000			13,000
Public Finance [Member] \| IA [Member] \| Other Public Finance Sectors [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			15,000
Public Finance [Member] \| II [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	5,000			0
Public Finance [Member] \| II [Member] \| Housing Revenue [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	5,000			0
Public Finance [Member] \| II [Member] \| Other Public Finance Sectors [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Public Finance [Member] \| III [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Public Finance [Member] \| III [Member] \| Housing Revenue [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Public Finance [Member] \| III [Member] \| Other Public Finance Sectors [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Public Finance [Member] \| IV [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Public Finance [Member] \| IV [Member] \| Housing Revenue [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Public Finance [Member] \| IV [Member] \| Other Public Finance Sectors [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	125,000			144,000
International Finance [Member] \| Sovereign/Sub-sovereign [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	93,000			108,000
International Finance [Member] \| Investor-owned and Public Utilities [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	28,000			31,000
International Finance [Member] \| Other International [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	5,000			5,000
International Finance [Member] \| Surveillance Category One [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	107,000			118,000
International Finance [Member] \| Surveillance Category One [Member] \| Sovereign/Sub-sovereign [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	74,000			82,000
International Finance [Member] \| Surveillance Category One [Member] \| Investor-owned and Public Utilities [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	28,000			31,000
International Finance [Member] \| Surveillance Category One [Member] \| Other International [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	5,000			5,000
International Finance [Member] \| IA [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	8,000			13,000
International Finance [Member] \| IA [Member] \| Sovereign/Sub-sovereign [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	8,000			13,000
International Finance [Member] \| IA [Member] \| Investor-owned and Public Utilities [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| IA [Member] \| Other International [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| II [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| II [Member] \| Sovereign/Sub-sovereign [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| II [Member] \| Investor-owned and Public Utilities [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| II [Member] \| Other International [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| III [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	11,000			13,000
International Finance [Member] \| III [Member] \| Sovereign/Sub-sovereign [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	11,000			13,000
International Finance [Member] \| III [Member] \| Investor-owned and Public Utilities [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| III [Member] \| Other International [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| IV [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| IV [Member] \| Sovereign/Sub-sovereign [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| IV [Member] \| Investor-owned and Public Utilities [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| IV [Member] \| Other International [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	$ 0			$ 0