$AMBC
AMBAC FINANCIAL GROUP INC Stock $ambc

$ambc Overview Financials Valuation SEC Filings Company Website

2021 Q4 Form 10-Q Financial Statement

#000087450121000152 Filed on November 08, 2021

Income Statement

Concept	2021 Q4	2021 Q3	2020 Q4
Revenue	$56.00M	$51.00M	$53.00M
YoY Change	5.66%	-17.74%	26.19%
Cost Of Revenue		-$55.00M
YoY Change
Gross Profit		$106.0M
YoY Change
Gross Profit Margin		207.84%
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$12.00M	$11.00M	$17.00M
YoY Change	-29.41%	-21.43%	15.65%
% of Gross Profit		10.38%
Operating Expenses	$31.00M	-$12.00M	$50.00M
YoY Change	-38.0%	-109.92%	-63.34%
Operating Profit		$118.0M
YoY Change
Interest Expense	-$45.00M	-$41.00M	-$42.00M
YoY Change	7.14%	-22.64%	-37.03%
% of Operating Profit		-34.75%
Other Income/Expense, Net	$1.000M
YoY Change
Pretax Income	-$19.00M	$19.00M	-$12.00M
YoY Change	58.33%	-117.59%	-89.19%
Income Tax	$3.000M	$2.000M	$2.000M
% Of Pretax Income		10.53%
Net Earnings	-$20.00M	$17.00M	-$14.00M
YoY Change	42.86%	-115.74%	-87.27%
Net Earnings / Revenue	-35.71%	33.33%	-26.42%
Basic Earnings Per Share		$0.35	-$0.31
Diluted Earnings Per Share	-$428.9K	$0.35	-$0.31
COMMON SHARES
Basic Shares Outstanding	46.30M shares	46.62M shares	45.81M shares
Diluted Shares Outstanding		47.04M shares

Balance Sheet

Concept	2021 Q4	2021 Q3	2020 Q4
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$17.00M	$14.00M	$20.00M
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$23.00M		$25.00M
YoY Change	-8.0%		0.0%
Goodwill	$46.00M		$46.00M
YoY Change	0.0%
Intangibles	$362.0M	$364.0M	$409.0M
YoY Change	-11.49%	-4.96%	-4.22%
Long-Term Investments	$9.128B	$9.049B	$51.00M
YoY Change	17798.04%	18367.35%	10.87%
Other Assets	$7.000M	$8.000M	$15.00M
YoY Change	-53.33%	-33.33%	-73.68%
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$12.30B	$12.23B	$13.22B
YoY Change	-6.94%	-4.56%	-0.75%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses	$576.0M	$555.0M	$547.0M
YoY Change	5.3%	11.22%	16.14%
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$576.0M	$557.0M	$553.0M
YoY Change	4.16%	11.62%	17.41%
LONG-TERM LIABILITIES
Long-Term Debt	$6.446B	$6.470B	$7.232B
YoY Change	-10.87%	-6.31%	-1.95%
Other Long-Term Liabilities	$2.167B	$2.032B	$2.023B
YoY Change	7.1%	2.21%	11.77%
Total Long-Term Liabilities	$8.613B	$8.502B	$9.255B
YoY Change	-6.94%	-4.41%	0.75%
TOTAL LIABILITIES
Total Short-Term Liabilities	$576.0M	$557.0M	$553.0M
Total Long-Term Liabilities	$8.613B	$8.502B	$9.255B
Total Liabilities	$11.19B	$11.09B	$12.07B
YoY Change	-7.35%	-5.38%	2.47%
SHAREHOLDERS EQUITY
Retained Earnings	$726.0M	$746.0M	$759.0M
YoY Change	-4.35%	-3.49%	-36.91%
Common Stock	$0.00	$0.00	$0.00
YoY Change
Preferred Stock
YoY Change
Treasury Stock (at cost)	$3.000M	$3.000M	$1.000M
YoY Change	200.0%	200.0%
Treasury Stock Shares	172.9K shares	185.0K shares	55.94K shares
Shareholders Equity	$1.038B	$1.061B	$1.080B
YoY Change
Total Liabilities & Shareholders Equity	$12.30B	$12.23B	$13.22B
YoY Change	-6.94%	-4.56%	-0.75%

Cashflow Statement

Concept	2021 Q4	2021 Q3	2020 Q4
OPERATING ACTIVITIES
Net Income	-$20.00M	$17.00M	-$14.00M
YoY Change	42.86%	-115.74%	-87.27%
Depreciation, Depletion And Amortization	$12.00M	$11.00M	$17.00M
YoY Change	-29.41%	-21.43%	15.65%
Cash From Operating Activities	$5.000M	-$52.00M	-$8.000M
YoY Change	-162.5%	-5.45%	-45.95%
INVESTING ACTIVITIES
Capital Expenditures
YoY Change
Acquisitions
YoY Change
Other Investing Activities	$31.00M	$558.0M	$36.00M
YoY Change	-13.89%	342.86%	-82.74%
Cash From Investing Activities	$31.00M	$558.0M	$36.00M
YoY Change	-13.89%	342.86%	-82.74%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-34.00M	-516.0M	-43.00M
YoY Change	-20.93%	838.18%	-76.16%
NET CHANGE
Cash From Operating Activities	5.000M	-52.00M	-8.000M
Cash From Investing Activities	31.00M	558.0M	36.00M
Cash From Financing Activities	-34.00M	-516.0M	-43.00M
Net Change In Cash	2.000M	-10.00M	-15.00M
YoY Change	-113.33%	-162.5%	-211.94%
FREE CASH FLOW
Cash From Operating Activities	$5.000M	-$52.00M	-$8.000M
Capital Expenditures
Free Cash Flow
YoY Change

Facts In Submission

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	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2021
	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q3
	dei	Entity Central Index Key EntityCentralIndexKey	0000874501
	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
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	dei	Document Type DocumentType	10-Q
	dei	Document Quarterly Report DocumentQuarterlyReport	true
	dei	Document Period End Date DocumentPeriodEndDate	2021-09-30
	dei	Document Transition Report DocumentTransitionReport	false
	dei	Entity File Number EntityFileNumber	1-10777
	dei	Entity Registrant Name EntityRegistrantName	AMBAC FINANCIAL GROUP, INC.
	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	13-3621676
	dei	Entity Address Address Line1 EntityAddressAddressLine1	One World Trade Center
	dei	Entity Address City Or Town EntityAddressCityOrTown	New York
	dei	Entity Address State Or Province EntityAddressStateOrProvince	NY
	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	10007
	dei	City Area Code CityAreaCode	(212)
	dei	Local Phone Number LocalPhoneNumber	658-7470
	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
	dei	Entity Small Business EntitySmallBusiness	false
	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
	dei	Entity Shell Company EntityShellCompany	false
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CY2020Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	0	USD
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	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	1000000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-4000000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	42000000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-2000000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	1000000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Foreign Currency Translation Gain Loss Arising During Period Tax OtherComprehensiveIncomeForeignCurrencyTranslationGainLossArisingDuringPeriodTax	0	USD
CY2020Q3	us-gaap	Other Comprehensive Income Foreign Currency Translation Gain Loss Arising During Period Tax OtherComprehensiveIncomeForeignCurrencyTranslationGainLossArisingDuringPeriodTax	0	USD
	us-gaap	Other Comprehensive Income Foreign Currency Translation Gain Loss Arising During Period Tax OtherComprehensiveIncomeForeignCurrencyTranslationGainLossArisingDuringPeriodTax	0	USD
	us-gaap	Other Comprehensive Income Foreign Currency Translation Gain Loss Arising During Period Tax OtherComprehensiveIncomeForeignCurrencyTranslationGainLossArisingDuringPeriodTax	0	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-19000000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	29000000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-11000000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-20000000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodTax	0	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodTax	0	USD
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodTax	0	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	0	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	0	USD
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-1000000	USD
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	2000000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Plan Amendments Tax Effect OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansPlanAmendmentsTaxEffect	0	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Plan Amendments Tax Effect OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansPlanAmendmentsTaxEffect	0	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Plan Amendments Tax Effect OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansPlanAmendmentsTaxEffect	0	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Plan Amendments Tax Effect OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansPlanAmendmentsTaxEffect	0	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	0	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	0	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	1000000	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	3000000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-23000000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	71000000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-15000000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-20000000	USD
CY2021Q3	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-6000000	USD
CY2020Q3	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-37000000	USD
	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-9000000	USD
	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-442000000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest	0	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest	-1000000	USD
CY2021Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-6000000	USD
CY2020Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-37000000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-10000000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-442000000	USD
CY2021Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.35
CY2020Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-2.33
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-0.19
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-9.16
CY2021Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.35
CY2020Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-2.33
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-0.19
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-9.16
CY2021Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	46615552	shares
CY2020Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	46178730	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	46503196	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	46135399	shares
CY2021Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	47044132	shares
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	10000000	USD
	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	-6000000	USD
	us-gaap	Minority Interest Change In Redemption Value MinorityInterestChangeInRedemptionValue	-14000000	USD
CY2021Q3	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1121000000	USD
CY2019Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1536000000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-442000000	USD
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	8000000	USD
	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	-3000000	USD
CY2020Q3	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1095000000	USD
	us-gaap	Net Income Loss NetIncomeLoss	5000000	USD
	us-gaap	Net Income Loss NetIncomeLoss	-423000000	USD
	us-gaap	Net Income Loss Attributable To Nonredeemable Noncontrolling Interest NetIncomeLossAttributableToNonredeemableNoncontrollingInterest	-1000000	USD
	us-gaap	Net Income Loss Attributable To Nonredeemable Noncontrolling Interest NetIncomeLossAttributableToNonredeemableNoncontrollingInterest	0	USD
	us-gaap	Profit Loss ProfitLoss	6000000	USD
	us-gaap	Profit Loss ProfitLoss	-423000000	USD
	us-gaap	Other Depreciation And Amortization OtherDepreciationAndAmortization	1000000	USD
	us-gaap	Other Depreciation And Amortization OtherDepreciationAndAmortization	1000000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	9000000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	12000000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	10000000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	8000000	USD
	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	-5000000	USD
	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	5000000	USD
	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	-4000000	USD
	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	9000000	USD
	us-gaap	Increase Decrease In Unearned Premiums IncreaseDecreaseInUnearnedPremiums	-75000000	USD
	us-gaap	Increase Decrease In Unearned Premiums IncreaseDecreaseInUnearnedPremiums	-40000000	USD
	us-gaap	Increase Decrease In Liability For Claims And Claims Adjustment Expense Reserve IncreaseDecreaseInLiabilityForClaimsAndClaimsAdjustmentExpenseReserve	148000000	USD
	us-gaap	Increase Decrease In Liability For Claims And Claims Adjustment Expense Reserve IncreaseDecreaseInLiabilityForClaimsAndClaimsAdjustmentExpenseReserve	-78000000	USD
	us-gaap	Increase Decrease In Reinsurance Payables IncreaseDecreaseInReinsurancePayables	7000000	USD
	us-gaap	Increase Decrease In Reinsurance Payables IncreaseDecreaseInReinsurancePayables	-2000000	USD
	us-gaap	Increase Decrease In Premiums Receivable IncreaseDecreaseInPremiumsReceivable	-44000000	USD
	us-gaap	Increase Decrease In Premiums Receivable IncreaseDecreaseInPremiumsReceivable	-44000000	USD
	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	75000000	USD
	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	69000000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	44000000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	41000000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	4000000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	20000000	USD
	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	33000000	USD
	us-gaap	Variable Interest Entity Activity Between Vie And Entity Operating Income Or Loss VariableInterestEntityActivityBetweenVIEAndEntityOperatingIncomeOrLoss	5000000	USD
	us-gaap	Variable Interest Entity Activity Between Vie And Entity Operating Income Or Loss VariableInterestEntityActivityBetweenVIEAndEntityOperatingIncomeOrLoss	3000000	USD
CY2020Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	46178730	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	46503196	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	46135399	shares
CY2021Q2	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1123000000	USD
CY2021Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-6000000	USD
CY2021Q3	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	4000000	USD
CY2021Q3	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	0	USD
CY2021Q3	us-gaap	Minority Interest Change In Redemption Value MinorityInterestChangeInRedemptionValue	0	USD
CY2021Q3	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1121000000	USD
CY2020Q2	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1129000000	USD
CY2020Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-37000000	USD
CY2020Q3	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	3000000	USD
CY2020Q3	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	0	USD
CY2020Q3	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1095000000	USD
CY2020Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1140000000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-10000000	USD
	us-gaap	Increase Decrease In Derivative Assets And Liabilities IncreaseDecreaseInDerivativeAssetsAndLiabilities	23000000	USD
	us-gaap	Increase Decrease In Derivative Assets And Liabilities IncreaseDecreaseInDerivativeAssetsAndLiabilities	-15000000	USD
	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	28000000	USD
	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-72000000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-136000000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-167000000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities ProceedsFromSaleOfAvailableForSaleSecurities	126000000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities ProceedsFromSaleOfAvailableForSaleSecurities	974000000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	658000000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	105000000	USD
	us-gaap	Payments To Acquire Available For Sale Securities PaymentsToAcquireAvailableForSaleSecurities	286000000	USD
	us-gaap	Payments To Acquire Available For Sale Securities PaymentsToAcquireAvailableForSaleSecurities	844000000	USD
	us-gaap	Proceeds From Sale And Maturity Of Other Investments ProceedsFromSaleAndMaturityOfOtherInvestments	75000000	USD
	us-gaap	Proceeds From Sale And Maturity Of Other Investments ProceedsFromSaleAndMaturityOfOtherInvestments	377000000	USD
	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	97000000	USD
	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	425000000	USD
	us-gaap	Payments For Proceeds From Short Term Investments PaymentsForProceedsFromShortTermInvestments	-125000000	USD
	us-gaap	Payments For Proceeds From Short Term Investments PaymentsForProceedsFromShortTermInvestments	-67000000	USD
	us-gaap	Increase Decrease Cash Collateral From Counterparties IncreaseDecreaseCashCollateralFromCounterparties	11000000	USD
	us-gaap	Increase Decrease Cash Collateral From Counterparties IncreaseDecreaseCashCollateralFromCounterparties	-2000000	USD
	ambc	Proceeds From Financial Guaranty Variable Interest Entity Assets ProceedsFromFinancialGuarantyVariableInterestEntityAssets	134000000	USD
	ambc	Proceeds From Financial Guaranty Variable Interest Entity Assets ProceedsFromFinancialGuarantyVariableInterestEntityAssets	142000000	USD
	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	0	USD
	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-2000000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	745000000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	396000000	USD
	us-gaap	Proceeds From Issuance Of Secured Debt ProceedsFromIssuanceOfSecuredDebt	1163000000	USD
	us-gaap	Proceeds From Issuance Of Debt ProceedsFromIssuanceOfDebt	7000000	USD
	ambc	Paydownof Ambac Note PaydownofAmbacNote	1641000000	USD
	ambc	Paydownof Ambac Note PaydownofAmbacNote	115000000	USD
	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	12000000	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	6000000	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	3000000	USD
	us-gaap	Proceeds From Payments To Minority Shareholders ProceedsFromPaymentsToMinorityShareholders	-1000000	USD
CY2020Q4	ambc	Business Combination Redeemable Noncontrolling Percentage BusinessCombinationRedeemableNoncontrollingPercentage	0.20
	ambc	Paydownof Financial Guaranty Variable Interest Entity Liabilities PaydownofFinancialGuarantyVariableInterestEntityLiabilities	133000000	USD
	ambc	Paydownof Financial Guaranty Variable Interest Entity Liabilities PaydownofFinancialGuarantyVariableInterestEntityLiabilities	143000000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-623000000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-260000000	USD
	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	0	USD
	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	0	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-14000000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-31000000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	35000000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	81000000	USD
CY2021Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	22000000	USD
CY2020Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	50000000	USD
	dei	Entity Incorporation Date Of Incorporation EntityIncorporationDateOfIncorporation	1991-04-29
CY2020Q4	us-gaap	Business Acquisition Percentage Of Voting Interests Acquired BusinessAcquisitionPercentageOfVotingInterestsAcquired	0.80
	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	33000000	USD
	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	-6000000	USD
	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	2000000	USD
CY2020Q4	us-gaap	Business Acquisition Percentage Of Voting Interests Acquired BusinessAcquisitionPercentageOfVotingInterestsAcquired	0.80
CY2020Q4	ambc	Business Combination Redeemable Noncontrolling Percentage BusinessCombinationRedeemableNoncontrollingPercentage	0.20
	us-gaap	Net Income Loss Attributable To Redeemable Noncontrolling Interest NetIncomeLossAttributableToRedeemableNoncontrollingInterest	-1000000	USD
	us-gaap	Minority Interest Change In Redemption Value MinorityInterestChangeInRedemptionValue	-14000000	USD
	us-gaap	Income Taxes Paid IncomeTaxesPaid	12000000	USD
	us-gaap	Income Taxes Paid IncomeTaxesPaid	11000000	USD
CY2021Q3	ambc	Reduction In Long Term Debt Through Long Term Debt Exchange ReductionInLongTermDebtThroughLongTermDebtExchange	71000000	USD
CY2021Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	14000000	USD
CY2020Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	37000000	USD
CY2021Q3	us-gaap	Restricted Cash RestrictedCash	6000000	USD
CY2020Q3	us-gaap	Restricted Cash RestrictedCash	10000000	USD
CY2021Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	22000000	USD
CY2020Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	50000000	USD
	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	<div style="margin-bottom:3pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-style:italic;font-weight:700;line-height:120%">Reclassifications and Rounding</span></div><div style="margin-bottom:6pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%">Reclassifications may have been made to prior years' amounts to conform to the current year's presentation. Certain amounts and tables in the consolidated financial statements and associated notes may not add due to rounding.</span></div>
	ambc	Number Of Variable Interest Entities Deconsolidated During Period NumberOfVariableInterestEntitiesDeconsolidatedDuringPeriod	0	consolidationVIE
CY2021Q3	ambc	Variable Interest Entity Changein Fair Valueof Assetsand Liabilities VariableInterestEntityChangeinFairValueofAssetsandLiabilities	2000000	USD
CY2020Q3	ambc	Variable Interest Entity Changein Fair Valueof Assetsand Liabilities VariableInterestEntityChangeinFairValueofAssetsandLiabilities	-1000000	USD
	ambc	Variable Interest Entity Changein Fair Valueof Assetsand Liabilities VariableInterestEntityChangeinFairValueofAssetsandLiabilities	2000000	USD
	ambc	Variable Interest Entity Changein Fair Valueof Assetsand Liabilities VariableInterestEntityChangeinFairValueofAssetsandLiabilities	-3000000	USD
CY2021Q3	us-gaap	Variable Interest Entity Activity Between Vie And Entity Income Or Loss Before Tax VariableInterestEntityActivityBetweenVIEAndEntityIncomeOrLossBeforeTax	3000000	USD
CY2020Q3	us-gaap	Variable Interest Entity Activity Between Vie And Entity Income Or Loss Before Tax VariableInterestEntityActivityBetweenVIEAndEntityIncomeOrLossBeforeTax	0	USD
	us-gaap	Variable Interest Entity Activity Between Vie And Entity Income Or Loss Before Tax VariableInterestEntityActivityBetweenVIEAndEntityIncomeOrLossBeforeTax	5000000	USD
	us-gaap	Variable Interest Entity Activity Between Vie And Entity Income Or Loss Before Tax VariableInterestEntityActivityBetweenVIEAndEntityIncomeOrLossBeforeTax	3000000	USD
CY2021Q3	ambc	Number Of Variable Interest Entities Consolidated During The Period NumberOfVariableInterestEntitiesConsolidatedDuringThePeriod	0	consolidationVIE
	ambc	Number Of Variable Interest Entities Consolidated During The Period NumberOfVariableInterestEntitiesConsolidatedDuringThePeriod	0	consolidationVIE
CY2021Q3	ambc	Number Of Variable Interest Entities Deconsolidated During Period NumberOfVariableInterestEntitiesDeconsolidatedDuringPeriod	0	consolidationVIE
	ambc	Number Of Variable Interest Entities Deconsolidated During Period NumberOfVariableInterestEntitiesDeconsolidatedDuringPeriod	1	consolidationVIE
CY2021Q3	us-gaap	Variable Interest Entity Entity Maximum Loss Exposure Amount VariableInterestEntityEntityMaximumLossExposureAmount	25515000000	USD
CY2021Q3	ambc	Variable Interest Entity Nonconsolidated Carrying Amount Insurance Assets VariableInterestEntityNonconsolidatedCarryingAmountInsuranceAssets	2228000000	USD
CY2021Q3	ambc	Variable Interest Entity Nonconsolidated Carrying Amount Insurance Liabilities VariableInterestEntityNonconsolidatedCarryingAmountInsuranceLiabilities	1018000000	USD
CY2021Q3	ambc	Variable Interest Entity Nonconsolidated Carrying Amount Derivative Net Assets Or Liabilities VariableInterestEntityNonconsolidatedCarryingAmountDerivativeNetAssetsOrLiabilities	5000000	USD
CY2020Q4	us-gaap	Variable Interest Entity Entity Maximum Loss Exposure Amount VariableInterestEntityEntityMaximumLossExposureAmount	27998000000	USD
CY2020Q4	ambc	Variable Interest Entity Nonconsolidated Carrying Amount Insurance Assets VariableInterestEntityNonconsolidatedCarryingAmountInsuranceAssets	2314000000	USD
CY2020Q4	ambc	Variable Interest Entity Nonconsolidated Carrying Amount Insurance Liabilities VariableInterestEntityNonconsolidatedCarryingAmountInsuranceLiabilities	1122000000	USD
CY2020Q4	us-gaap	Equity Method Investments Fair Value Disclosure EquityMethodInvestmentsFairValueDisclosure	1000000	USD
CY2021Q2	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	87000000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-20000000	USD
CY2021Q3	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	3000000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-23000000	USD
CY2021Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	64000000	USD
CY2020Q2	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-48000000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	74000000	USD
CY2020Q3	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	3000000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	71000000	USD
CY2020Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	22000000	USD
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	79000000	USD
	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-9000000	USD
	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	6000000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-15000000	USD
CY2021Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	64000000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	42000000	USD
	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-2000000	USD
	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	18000000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-20000000	USD
CY2020Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	22000000	USD
CY2021Q3	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	46292043	shares
CY2013Q2	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2021Q3	us-gaap	Class Of Warrant Or Right Outstanding ClassOfWarrantOrRightOutstanding	4877617	shares
CY2013Q2	us-gaap	Class Of Warrant Or Right Exercise Price Of Warrants Or Rights1 ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1	16.67
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	17000000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	-108000000	USD
	us-gaap	Net Income Loss NetIncomeLoss	5000000	USD
	us-gaap	Net Income Loss NetIncomeLoss	-423000000	USD
CY2021Q3	us-gaap	Minority Interest Change In Redemption Value MinorityInterestChangeInRedemptionValue	0	USD
	us-gaap	Minority Interest Change In Redemption Value MinorityInterestChangeInRedemptionValue	-14000000	USD
CY2021Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	17000000	USD
CY2020Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-108000000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-9000000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-423000000	USD
CY2021Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.35
CY2020Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-2.33
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-0.19
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-9.16
CY2021Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.35
CY2020Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-2.33
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-0.19
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-9.16
CY2021Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	46615552	shares
CY2020Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	46178730	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	46503196	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	46135399	shares
CY2021Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	47044132	shares
CY2020Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	46178730	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	46503196	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	46135399	shares
CY2021Q3	us-gaap	Direct Premiums Written DirectPremiumsWritten	-1000000	USD
CY2021Q3	us-gaap	Direct Premiums Earned DirectPremiumsEarned	15000000	USD
CY2020Q3	us-gaap	Direct Premiums Written DirectPremiumsWritten	-13000000	USD
CY2020Q3	us-gaap	Direct Premiums Earned DirectPremiumsEarned	18000000	USD
CY2021Q3	us-gaap	Assumed Premiums Written AssumedPremiumsWritten	0	USD
CY2021Q3	us-gaap	Assumed Premiums Earned AssumedPremiumsEarned	0	USD
CY2020Q3	us-gaap	Assumed Premiums Written AssumedPremiumsWritten	0	USD
CY2020Q3	us-gaap	Assumed Premiums Earned AssumedPremiumsEarned	0	USD
CY2021Q3	us-gaap	Ceded Premiums Written CededPremiumsWritten	14000000	USD
CY2021Q3	us-gaap	Ceded Premiums Earned CededPremiumsEarned	4000000	USD
CY2020Q3	us-gaap	Ceded Premiums Written CededPremiumsWritten	0	USD
CY2020Q3	us-gaap	Ceded Premiums Earned CededPremiumsEarned	3000000	USD
CY2021Q3	us-gaap	Premiums Written Net PremiumsWrittenNet	-15000000	USD
CY2021Q3	us-gaap	Premiums Earned Net PremiumsEarnedNet	11000000	USD
CY2020Q3	us-gaap	Premiums Written Net PremiumsWrittenNet	-13000000	USD
CY2020Q3	us-gaap	Premiums Earned Net PremiumsEarnedNet	15000000	USD
	us-gaap	Direct Premiums Written DirectPremiumsWritten	-6000000	USD
	us-gaap	Direct Premiums Earned DirectPremiumsEarned	46000000	USD
	us-gaap	Direct Premiums Written DirectPremiumsWritten	-2000000	USD
	us-gaap	Direct Premiums Earned DirectPremiumsEarned	45000000	USD
	us-gaap	Assumed Premiums Written AssumedPremiumsWritten	0	USD
	us-gaap	Assumed Premiums Earned AssumedPremiumsEarned	0	USD
	us-gaap	Assumed Premiums Written AssumedPremiumsWritten	0	USD
	us-gaap	Assumed Premiums Earned AssumedPremiumsEarned	1000000	USD
	us-gaap	Ceded Premiums Written CededPremiumsWritten	29000000	USD
	us-gaap	Ceded Premiums Earned CededPremiumsEarned	10000000	USD
	us-gaap	Ceded Premiums Written CededPremiumsWritten	-1000000	USD
	us-gaap	Ceded Premiums Earned CededPremiumsEarned	9000000	USD
	us-gaap	Premiums Written Net PremiumsWrittenNet	-36000000	USD
	us-gaap	Premiums Earned Net PremiumsEarnedNet	36000000	USD
	us-gaap	Premiums Written Net PremiumsWrittenNet	-2000000	USD
	us-gaap	Premiums Earned Net PremiumsEarnedNet	36000000	USD
CY2021Q3	us-gaap	Premiums Earned Net PremiumsEarnedNet	11000000	USD
CY2020Q3	us-gaap	Premiums Earned Net PremiumsEarnedNet	15000000	USD
	us-gaap	Premiums Earned Net PremiumsEarnedNet	36000000	USD
	us-gaap	Premiums Earned Net PremiumsEarnedNet	36000000	USD
CY2021Q3	us-gaap	Premiums Receivable At Carrying Value PremiumsReceivableAtCarryingValue	327000000	USD
CY2020Q4	us-gaap	Premiums Receivable At Carrying Value PremiumsReceivableAtCarryingValue	370000000	USD
CY2021Q3	ambc	Estimated Future Premium Payments Weighted Average Discounted Rate EstimatedFuturePremiumPaymentsWeightedAverageDiscountedRate	0.022
CY2020Q4	ambc	Estimated Future Premium Payments Weighted Average Discounted Rate EstimatedFuturePremiumPaymentsWeightedAverageDiscountedRate	0.022
	us-gaap	Financial Guarantee Insurance Contracts Premium Received Over Contract Period Premium Receivable Weighted Average Collection Period1 FinancialGuaranteeInsuranceContractsPremiumReceivedOverContractPeriodPremiumReceivableWeightedAverageCollectionPeriod1	P8Y1M6D
CY2020	us-gaap	Financial Guarantee Insurance Contracts Premium Received Over Contract Period Premium Receivable Weighted Average Collection Period1 FinancialGuaranteeInsuranceContractsPremiumReceivedOverContractPeriodPremiumReceivableWeightedAverageCollectionPeriod1	P8Y3M18D
CY2021Q3	us-gaap	Premiums Receivable Gross PremiumsReceivableGross	335000000	USD
CY2020Q4	us-gaap	Premiums Receivable Gross PremiumsReceivableGross	387000000	USD
CY2021Q2	us-gaap	Allowance For Doubtful Accounts Premiums And Other Receivables AllowanceForDoubtfulAccountsPremiumsAndOtherReceivables	11000000	USD
CY2020Q2	us-gaap	Allowance For Doubtful Accounts Premiums And Other Receivables AllowanceForDoubtfulAccountsPremiumsAndOtherReceivables	16000000	USD
CY2020Q4	us-gaap	Allowance For Doubtful Accounts Premiums And Other Receivables AllowanceForDoubtfulAccountsPremiumsAndOtherReceivables	17000000	USD
CY2019Q4	us-gaap	Allowance For Doubtful Accounts Premiums And Other Receivables AllowanceForDoubtfulAccountsPremiumsAndOtherReceivables	9000000	USD
CY2021Q3	us-gaap	Premium Receivable Credit Loss Expense Reversal PremiumReceivableCreditLossExpenseReversal	-1000000	USD
CY2020Q3	us-gaap	Premium Receivable Credit Loss Expense Reversal PremiumReceivableCreditLossExpenseReversal	2000000	USD
	us-gaap	Premium Receivable Credit Loss Expense Reversal PremiumReceivableCreditLossExpenseReversal	-6000000	USD
	us-gaap	Premium Receivable Credit Loss Expense Reversal PremiumReceivableCreditLossExpenseReversal	9000000	USD
CY2021Q3	us-gaap	Premiums Receivable Allowance For Doubtful Accounts Write Offs Against Allowance PremiumsReceivableAllowanceForDoubtfulAccountsWriteOffsAgainstAllowance	0	USD
CY2020Q3	us-gaap	Premiums Receivable Allowance For Doubtful Accounts Write Offs Against Allowance PremiumsReceivableAllowanceForDoubtfulAccountsWriteOffsAgainstAllowance	0	USD
	us-gaap	Premiums Receivable Allowance For Doubtful Accounts Write Offs Against Allowance PremiumsReceivableAllowanceForDoubtfulAccountsWriteOffsAgainstAllowance	-1000000	USD
	us-gaap	Premiums Receivable Allowance For Doubtful Accounts Write Offs Against Allowance PremiumsReceivableAllowanceForDoubtfulAccountsWriteOffsAgainstAllowance	0	USD
CY2021Q3	us-gaap	Premiums Receivable Allowance For Doubtful Accounts Recoveries PremiumsReceivableAllowanceForDoubtfulAccountsRecoveries	0	USD
CY2020Q3	us-gaap	Premiums Receivable Allowance For Doubtful Accounts Recoveries PremiumsReceivableAllowanceForDoubtfulAccountsRecoveries	0	USD
	us-gaap	Premiums Receivable Allowance For Doubtful Accounts Recoveries PremiumsReceivableAllowanceForDoubtfulAccountsRecoveries	0	USD
	us-gaap	Premiums Receivable Allowance For Doubtful Accounts Recoveries PremiumsReceivableAllowanceForDoubtfulAccountsRecoveries	0	USD
CY2021Q3	us-gaap	Allowance For Doubtful Accounts Premiums And Other Receivables AllowanceForDoubtfulAccountsPremiumsAndOtherReceivables	10000000	USD
CY2020Q3	us-gaap	Allowance For Doubtful Accounts Premiums And Other Receivables AllowanceForDoubtfulAccountsPremiumsAndOtherReceivables	18000000	USD
CY2021Q3	us-gaap	Allowance For Doubtful Accounts Premiums And Other Receivables AllowanceForDoubtfulAccountsPremiumsAndOtherReceivables	10000000	USD
CY2020Q3	us-gaap	Allowance For Doubtful Accounts Premiums And Other Receivables AllowanceForDoubtfulAccountsPremiumsAndOtherReceivables	18000000	USD
CY2019Q4	us-gaap	Allowance For Doubtful Accounts Premiums And Other Receivables AllowanceForDoubtfulAccountsPremiumsAndOtherReceivables	9000000	USD
CY2020Q4	us-gaap	Financial Guarantee Insurance Contracts Premium Receivable FinancialGuaranteeInsuranceContractsPremiumReceivable	370000000	USD
CY2019Q4	us-gaap	Financial Guarantee Insurance Contracts Premium Receivable FinancialGuaranteeInsuranceContractsPremiumReceivable	416000000	USD
	us-gaap	Financial Guarantee Insurance Contracts Premium Receivable Proceeds From Premiums Received FinancialGuaranteeInsuranceContractsPremiumReceivableProceedsFromPremiumsReceived	-28000000	USD
	us-gaap	Financial Guarantee Insurance Contracts Premium Receivable Proceeds From Premiums Received FinancialGuaranteeInsuranceContractsPremiumReceivableProceedsFromPremiumsReceived	-36000000	USD
	us-gaap	Financial Guarantee Insurance Contracts Premiums Receivable Adjustment Change In Period Of Contract FinancialGuaranteeInsuranceContractsPremiumsReceivableAdjustmentChangeInPeriodOfContract	-25000000	USD
	us-gaap	Financial Guarantee Insurance Contracts Premiums Receivable Adjustment Change In Period Of Contract FinancialGuaranteeInsuranceContractsPremiumsReceivableAdjustmentChangeInPeriodOfContract	-4000000	USD
	us-gaap	Financial Guarantee Insurance Contracts Premiums Receivable Accretion Of Discount On Premium Receivable FinancialGuaranteeInsuranceContractsPremiumsReceivableAccretionOfDiscountOnPremiumReceivable	6000000	USD
	us-gaap	Financial Guarantee Insurance Contracts Premiums Receivable Accretion Of Discount On Premium Receivable FinancialGuaranteeInsuranceContractsPremiumsReceivableAccretionOfDiscountOnPremiumReceivable	7000000	USD
	us-gaap	Premiums Receivable Allowance For Doubtful Accounts Period Increase Decrease PremiumsReceivableAllowanceForDoubtfulAccountsPeriodIncreaseDecrease	7000000	USD
	us-gaap	Premiums Receivable Allowance For Doubtful Accounts Period Increase Decrease PremiumsReceivableAllowanceForDoubtfulAccountsPeriodIncreaseDecrease	-5000000	USD
	us-gaap	Financial Guarantee Insurance Contracts Premiums Receivable Adjustment Other Adjustments FinancialGuaranteeInsuranceContractsPremiumsReceivableAdjustmentOtherAdjustments	-4000000	USD
	us-gaap	Financial Guarantee Insurance Contracts Premiums Receivable Adjustment Other Adjustments FinancialGuaranteeInsuranceContractsPremiumsReceivableAdjustmentOtherAdjustments	-2000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Premium Receivable FinancialGuaranteeInsuranceContractsPremiumReceivable	325000000	USD
CY2020Q3	us-gaap	Financial Guarantee Insurance Contracts Premium Receivable FinancialGuaranteeInsuranceContractsPremiumReceivable	372000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Premium Expected To Be Collected During Fourth Quarter Following Balance Sheet Date FinancialGuaranteeInsuranceContractsPremiumExpectedToBeCollectedDuringFourthQuarterFollowingBalanceSheetDate	8000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Future Expected Premium Revenue To Be Recognized During Fourth Quarter Following Balance Sheet Date FinancialGuaranteeInsuranceContractsFutureExpectedPremiumRevenueToBeRecognizedDuringFourthQuarterFollowingBalanceSheetDate	7000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Premium Expected To Be Collected More Than One And Within Two Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsPremiumExpectedToBeCollectedMoreThanOneAndWithinTwoYearsFromBalanceSheetDate	33000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Future Expected Premium Revenue To Be Recognized More Than One And Within Two Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsFutureExpectedPremiumRevenueToBeRecognizedMoreThanOneAndWithinTwoYearsFromBalanceSheetDate	27000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Premium Expected To Be Collected More Than Two And Within Three Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsPremiumExpectedToBeCollectedMoreThanTwoAndWithinThreeYearsFromBalanceSheetDate	32000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Future Expected Premium Revenue To Be Recognized More Than Two And Within Three Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsFutureExpectedPremiumRevenueToBeRecognizedMoreThanTwoAndWithinThreeYearsFromBalanceSheetDate	26000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Premium Expected To Be Collected More Than Three And Within Four Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsPremiumExpectedToBeCollectedMoreThanThreeAndWithinFourYearsFromBalanceSheetDate	30000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Future Expected Premium Revenue To Be Recognized More Than Three And Within Four Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsFutureExpectedPremiumRevenueToBeRecognizedMoreThanThreeAndWithinFourYearsFromBalanceSheetDate	25000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Premium Expected To Be Collected More Than Four And Within Five Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsPremiumExpectedToBeCollectedMoreThanFourAndWithinFiveYearsFromBalanceSheetDate	29000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Future Expected Premium Revenue To Be Recognized More Than Four And Within Five Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsFutureExpectedPremiumRevenueToBeRecognizedMoreThanFourAndWithinFiveYearsFromBalanceSheetDate	23000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Premium Expected To Be Collected More Than Five And Within10 Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsPremiumExpectedToBeCollectedMoreThanFiveAndWithin10YearsFromBalanceSheetDate	122000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Future Expected Premium Revenue To Be Recognized More Than Five And Within10 Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsFutureExpectedPremiumRevenueToBeRecognizedMoreThanFiveAndWithin10YearsFromBalanceSheetDate	98000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Premium Expected To Be Collected More Than10 And Within15 Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsPremiumExpectedToBeCollectedMoreThan10AndWithin15YearsFromBalanceSheetDate	84000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Future Expected Premium Revenue To Be Recognized More Than10 And Within15 Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsFutureExpectedPremiumRevenueToBeRecognizedMoreThan10AndWithin15YearsFromBalanceSheetDate	62000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Premium Expected To Be Collected More Than15 And Within20 Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsPremiumExpectedToBeCollectedMoreThan15AndWithin20YearsFromBalanceSheetDate	39000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Future Expected Premium Revenue To Be Recognized More Than15 And Within20 Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsFutureExpectedPremiumRevenueToBeRecognizedMoreThan15AndWithin20YearsFromBalanceSheetDate	27000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Premium Expected To Be Collected More Than20 And Within25 Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsPremiumExpectedToBeCollectedMoreThan20AndWithin25YearsFromBalanceSheetDate	18000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Future Expected Premium Revenue To Be Recognized More Than20 And Within25 Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsFutureExpectedPremiumRevenueToBeRecognizedMoreThan20AndWithin25YearsFromBalanceSheetDate	11000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Premium Expected To Be Collected More Than25 And Within30 Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsPremiumExpectedToBeCollectedMoreThan25AndWithin30YearsFromBalanceSheetDate	7000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Future Expected Premium Revenue To Be Recognized More Than25 And Within30 Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsFutureExpectedPremiumRevenueToBeRecognizedMoreThan25AndWithin30YearsFromBalanceSheetDate	4000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Premium Expected To Be Collected More Than30 And Within35 Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsPremiumExpectedToBeCollectedMoreThan30AndWithin35YearsFromBalanceSheetDate	1000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Future Expected Premium Revenue To Be Recognized More Than30 And Within35 Years From Balance Sheet Date FinancialGuaranteeInsuranceContractsFutureExpectedPremiumRevenueToBeRecognizedMoreThan30AndWithin35YearsFromBalanceSheetDate	0	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Premium Receivable Premium Expected To Be Collected FinancialGuaranteeInsuranceContractsPremiumReceivablePremiumExpectedToBeCollected	401000000	USD
CY2021Q3	us-gaap	Financial Guarantee Insurance Contracts Future Expected Premium Revenue To Be Recognized FinancialGuaranteeInsuranceContractsFutureExpectedPremiumRevenueToBeRecognized	310000000	USD
CY2021Q3	ambc	Liability For Unpaid Claims And Claims Adjustment Expense Gross Of Subrogation Recoverable LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseGrossOfSubrogationRecoverable	1565000000	USD
CY2020Q4	ambc	Liability For Unpaid Claims And Claims Adjustment Expense Gross Of Subrogation Recoverable LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseGrossOfSubrogationRecoverable	1759000000	USD
CY2021Q3	us-gaap	Salvage And Subrogation Recoveries Value SalvageAndSubrogationRecoveriesValue	2113000000	USD
CY2020Q4	us-gaap	Salvage And Subrogation Recoveries Value SalvageAndSubrogationRecoveriesValue	2156000000	USD
CY2021Q3	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	-549000000	USD
CY2020Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	-397000000	USD
	us-gaap	Schedule Of Liability For Unpaid Claims And Claims Adjustment Expense ScheduleOfLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense	<div style="margin-bottom:3pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:9pt;font-weight:400;line-height:120%">Below is the loss and loss reserve expense roll-forward, net of subrogation recoverable and reinsurance, for the affected periods:</span></div><div style="margin-top:9pt;text-align:justify"><table style="border-collapse:collapse;display:inline-table;margin-bottom:5pt;vertical-align:text-bottom;width:99.371%"><tr><td style="width:1.0%"/><td style="width:58.710%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:18.203%"/><td style="width:0.1%"/><td style="width:0.1%"/><td style="width:1.382%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:18.205%"/><td style="width:0.1%"/></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">Nine Months Ended September 30,</span></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">2021</span></td><td colspan="3" style="padding:0 1pt"/><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">2020</span></td></tr><tr><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">Beginning gross loss and loss expense reserves</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">$</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">(397)</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">$</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">(482)</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Reinsurance recoverable</span></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">33</span><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">26 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Beginning balance of net loss and loss expense reserves</span></td><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">(430)</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(508)</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">Losses and loss expenses (benefit):</span></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Current year</span></td><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">—</span><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">18 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="padding-left:11.25pt;text-indent:-4.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Prior years</span></div></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">(73)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">198 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="padding-left:11.25pt;text-indent:-4.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Total </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:5.2pt;font-weight:400;line-height:100%;position:relative;top:-2.8pt;vertical-align:baseline">(1) (2)</span></div></td><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">(73)</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">216 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="padding-left:4.5pt;text-indent:-4.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">Loss and loss expenses paid (recovered):</span></div></td><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Current year</span></td><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">—</span><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">1 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Prior years</span></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">74</span><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">137 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="padding-left:11.25pt;text-indent:-4.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Total</span></div></td><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">74</span><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">138 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="padding-left:4.5pt;text-indent:-4.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Foreign exchange effect</span></div></td><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">—</span><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">1 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="padding-left:4.5pt;text-indent:-4.5pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Ending net loss and loss expense reserves </span></div></td><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">(577)</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">(429)</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/><td colspan="3" style="display:none"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">Reinsurance recoverable </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:5.2pt;font-weight:400;line-height:100%;position:relative;top:-2.8pt;vertical-align:baseline">(3)</span></div></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">29</span><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%"> </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:100%">36 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">Ending gross loss and loss expense reserves</span></td><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">$</span></td><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#2a1aff;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">(549)</span></td><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:0 1pt"/><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">$</span></td><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:700;line-height:100%">(393)</span></td><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr></table></div><div style="margin-bottom:3pt;margin-top:4pt;padding-left:18pt;text-align:justify;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%">(1)</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%;padding-left:8.68pt">Total losses and loss expenses (benefit) includes $2 and $(14) for the nine months ended September 30, 2021 and 2020, respectively, related to ceded reinsurance.</span></div><div style="margin-bottom:3pt;padding-left:18pt;text-align:justify;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%">(2)</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%;padding-left:8.68pt">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&W's for the nine months ended September 30, 2021 and 2020, was $19 and $(29), respectively.</span></div><div style="margin-bottom:12pt;padding-left:18pt;text-align:justify;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%">(3)</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%;padding-left:8.68pt">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 September 30, 2021 and 2020, respectively, related to previously presented loss and loss expenses and subrogation.</span></div>
CY2020Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	-397000000	USD
CY2019Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	-482000000	USD
CY2020Q4	ambc	Loss Reserves Ceded To Reinsurers LossReservesCededToReinsurers	33000000	USD
CY2019Q4	ambc	Loss Reserves Ceded To Reinsurers LossReservesCededToReinsurers	26000000	USD
CY2020Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	-430000000	USD
CY2019Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	-508000000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	0	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	18000000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	-73000000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	198000000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	-73000000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	216000000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	0	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	1000000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	74000000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	137000000	USD
	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	74000000	USD
	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	138000000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Foreign Currency Translation Gain Loss LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForeignCurrencyTranslationGainLoss	0	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Foreign Currency Translation Gain Loss LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForeignCurrencyTranslationGainLoss	1000000	USD
CY2021Q3	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	-577000000	USD
CY2020Q3	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	-429000000	USD
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CY2021Q3	us-gaap	Net Investment Income NetInvestmentIncome	21000000	USD
CY2020Q3	us-gaap	Net Investment Income NetInvestmentIncome	37000000	USD
	us-gaap	Net Investment Income NetInvestmentIncome	112000000	USD
	us-gaap	Net Investment Income NetInvestmentIncome	69000000	USD
CY2021Q3	us-gaap	Net Realized Or Unrealized Gain Loss On Trading Securities NetRealizedOrUnrealizedGainLossOnTradingSecurities	0	USD
CY2020Q3	us-gaap	Net Realized Or Unrealized Gain Loss On Trading Securities NetRealizedOrUnrealizedGainLossOnTradingSecurities	3000000	USD
CY2021Q3	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	0	USD
CY2020Q3	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	0	USD
CY2021Q3	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	78000000	USD
CY2021Q3	us-gaap	Derivative Fair Value Of Derivative Asset Amount Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral	0	USD
CY2021Q3	us-gaap	Derivative Assets DerivativeAssets	78000000	USD
CY2021Q3	us-gaap	Derivative Fair Value Of Derivative Asset Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral	0	USD
CY2021Q3	ambc	Derivative Assets Net Amount DerivativeAssetsNetAmount	78000000	USD
CY2021Q3	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	94000000	USD
CY2021Q3	us-gaap	Derivative Fair Value Of Derivative Liability Amount Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral	0	USD
CY2021Q3	us-gaap	Derivative Liabilities DerivativeLiabilities	94000000	USD
CY2021Q3	us-gaap	Derivative Fair Value Of Derivative Liability Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral	93000000	USD
CY2021Q3	ambc	Derivative Liabilities Net Amount DerivativeLiabilitiesNetAmount	1000000	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	93000000	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Asset Amount Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral	0	USD
CY2020Q4	us-gaap	Derivative Assets DerivativeAssets	93000000	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Asset Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral	0	USD
CY2020Q4	ambc	Derivative Assets Net Amount DerivativeAssetsNetAmount	93000000	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	114000000	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Liability Amount Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral	0	USD
CY2020Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	114000000	USD
CY2020Q4	ambc	Derivative Liabilities Gross Amount Of Collateral Cash And Securities Pledged Not Offset DerivativeLiabilitiesGrossAmountOfCollateralCashAndSecuritiesPledgedNotOffset	113000000	USD
CY2020Q4	ambc	Derivative Liabilities Net Amount DerivativeLiabilitiesNetAmount	1000000	USD
CY2021Q3	us-gaap	Derivative Collateral Right To Reclaim Cash DerivativeCollateralRightToReclaimCash	9000000	USD
CY2020Q4	us-gaap	Derivative Collateral Right To Reclaim Cash DerivativeCollateralRightToReclaimCash	1000000	USD
CY2021Q3	us-gaap	Derivative Collateral Obligation To Return Cash DerivativeCollateralObligationToReturnCash	0	USD
CY2021Q3	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	5000000	USD
CY2020Q3	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	7000000	USD
	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	19000000	USD
	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	-61000000	USD
CY2021Q3	ambc	Derivative Gain Losson Derivatives Total Net DerivativeGainLossonDerivativesTotalNet	-77000000	USD
CY2020Q3	ambc	Derivative Gain Losson Derivatives Total Net DerivativeGainLossonDerivativesTotalNet	-7000000	USD
	ambc	Derivative Gain Losson Derivatives Total Net DerivativeGainLossonDerivativesTotalNet	-29000000	USD
	ambc	Derivative Gain Losson Derivatives Total Net DerivativeGainLossonDerivativesTotalNet	-231000000	USD
CY2021Q3	us-gaap	Derivative Net Liability Position Aggregate Fair Value DerivativeNetLiabilityPositionAggregateFairValue	93000000	USD
CY2020Q4	us-gaap	Derivative Net Liability Position Aggregate Fair Value DerivativeNetLiabilityPositionAggregateFairValue	113000000	USD
CY2021Q3	us-gaap	Collateral Already Posted Aggregate Fair Value CollateralAlreadyPostedAggregateFairValue	110000000	USD
CY2020Q4	us-gaap	Collateral Already Posted Aggregate Fair Value CollateralAlreadyPostedAggregateFairValue	130000000	USD
CY2021Q3	us-gaap	Long Term Debt And Capital Lease Obligations Repayments Of Principal In Next Twelve Months LongTermDebtAndCapitalLeaseObligationsRepaymentsOfPrincipalInNextTwelveMonths	780000000	USD
CY2021Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Rolling Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearTwo	0	USD
CY2021Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Rolling Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearThree	0	USD
CY2021Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Rolling Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearFour	0	USD
CY2021Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Rolling Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingYearFive	1175000000	USD
CY2021Q3	us-gaap	Long Term Debt Maturities Repayments Of Principal In Rolling After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInRollingAfterYearFive	366000000	USD
CY2020Q2	us-gaap	Debt Instrument Interest Rate Effective Percentage DebtInstrumentInterestRateEffectivePercentage	0.101
CY2021Q3	us-gaap	Debt Instrument Interest Rate Effective Percentage DebtInstrumentInterestRateEffectivePercentage	0.089
CY2021Q3	ambc	Rep Warranty Subrogation Recoveries Up To RepWarrantySubrogationRecoveriesUpTo	1400000000	USD
CY2021Q3	ambc	Rep Warranty Subrogation Recoveries Up To RepWarrantySubrogationRecoveriesUpTo	1400000000	USD
CY2021Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	8000000	USD
CY2020Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	-106000000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	-2000000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	-412000000	USD
CY2021Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	11000000	USD
CY2020Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	-2000000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	23000000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	-15000000	USD
CY2021Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	19000000	USD
CY2020Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	-108000000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	21000000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	-427000000	USD
CY2021Q3	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	0	USD
CY2020Q3	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	0	USD
	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	0	USD
	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	0	USD
CY2021Q3	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	0	USD
CY2020Q3	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	0	USD
	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	1000000	USD
	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	0	USD
CY2021Q3	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	2000000	USD
CY2020Q3	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	-1000000	USD
	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	7000000	USD
	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	0	USD
CY2021Q3	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	2000000	USD
CY2020Q3	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	-1000000	USD
	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	9000000	USD
	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	1000000	USD
CY2021Q3	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	0	USD
CY2020Q3	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	1000000	USD
	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	6000000	USD
	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-5000000	USD
CY2021Q3	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	0	USD
CY2020Q3	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	1000000	USD
	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	6000000	USD
	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-5000000	USD
CY2021Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	2000000	USD
CY2020Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	0	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	15000000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-5000000	USD
CY2021Q3	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1121000000	USD
CY2021Q3	ambc	Public Finance Puerto Rico Net Par Outstanding PublicFinancePuertoRicoNetParOutstanding	1054000000	USD

Files In Submission

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$AMBC
AMBAC FINANCIAL GROUP INC Stock $ambc

2021 Q4 Form 10-Q Financial Statement

#000087450121000152 Filed on November 08, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$AMBC AMBAC FINANCIAL GROUP INC Stock $ambc

2021 Q4 Form 10-Q Financial Statement

#000087450121000152 Filed on November 08, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$AMBC
AMBAC FINANCIAL GROUP INC Stock $ambc