Financial Guarantee Insurance Contracts, Consolidation of VIE

No definition available.

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

- Definition

Insurance [Line Items]

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Past Due Premiums

+ References

No definition available.

+ Details

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Namespace Prefix:	ambc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

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

+ References

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Period Type:	instant

- Definition

Amount of the premium receivable for financial guarantee insurance contracts reported in the statement of financial position. This element primarily would consist of those financial guarantee insurance contracts which premiums are to be collected over the contract period, but may, on occasion, include premiums which are to be collected in full at inception, but which straddle a financial reporting period.

+ References

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+ Details

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Period Type:	instant

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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- Definition

Amount of accretion of the discount for premiums receivable on financial guarantee insurance contracts.

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+ Details

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Period Type:	duration

- Definition

Amount of increase (decrease) in the premium receivable on financial guarantee insurance contracts from changes in the period of the contract.

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- Definition

Amount of increase (decrease) in the premiums receivable on financial guarantee insurance contracts from adjustments classified as other.

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- Definition

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

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition

The carrying value as of the balance sheet date of the estimated valuation allowance to reduce gross premiums receivable to net realizable value.

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- Definition

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

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- Definition

Amount of increase in allowance for credit loss on premium receivable from recovery.

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- Definition

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

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- Definition

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

+ References

+ Details

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- Definition

Amount of direct and assumed premiums written.

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- Definition

Cash received as payments for insurance premiums during the current period.

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- Definition

Amount of equity (deficit) attributable to parent and noncontrolling interest. Excludes temporary equity.

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Financial Guarantee Insurance Contracts - Summary of Gross Premium Receivable Roll-Forward (Direct and Assumed Contracts) (Detail) € in Millions, £ in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2023 GBP (£)	Dec. 31, 2023 EUR (€)	Dec. 31, 2022 USD ($)	Dec. 31, 2022 GBP (£)	Dec. 31, 2022 EUR (€)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Insurance [Line Items]
Premium Receivable, Allowance for Credit Loss	$ 4			$ 5
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,415			1,305			$ 1,098	$ 1,140
Premiums Written, Net	210			117			10
Proceeds from Insurance Premiums Collected	(208)			(139)			(43)
Adjustments for changes in expected and contractual cash flows	6			(31)			(27)
Accretion of premium receivable discount	8			8			8
Financial Guarantee Insurance Contracts, Consolidation of VIE	(1)
Other adjustments (including foreign exchange)	4			(12)			(4)
Allowance for Doubtful Accounts, Premiums and Other Receivables	4			5			9	17
Premium Receivable, Credit Loss Expense (Reversal)	(1)			(4)			(6)
Premium Receivable, Allowance for Credit Loss, Writeoff	0			0			(2)
Premiums Receivable, Gross	290			269			323	$ 370
Premium Receivable, Allowance for Credit Loss, Recovery	0			0			0
Past Due Premiums	1			0
Premium Receivable, Allowance for Credit Loss, Period Increase (Decrease)	1			4			8
Foreign Exchange \| Real Estate [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Other adjustments (including foreign exchange)	4			(13)			(2)
Specialty Property & Casualty Program [Domain]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	46			16
Legacy Financial Guarantee
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	248			259
Surveillance Category One [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	210			217
IA [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	16			10
II [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	5			5
III [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	7			16
IV [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	11			11
United Kingdom, Pounds
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Beginning premium receivable	71	£ 59		108	£ 80
Ending premium receivable	72	£ 57		71	£ 59		108
Euro Member Countries, Euro
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Beginning premium receivable	14		€ 13	16		€ 14
Ending premium receivable	13		€ 12	14		€ 13	$ 16
Structured Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	22			24
Structured Finance [Member] \| Mortgage-backed and Home Equity [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	12			11
Structured Finance [Member] \| Student Loan [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	7			8
Structured Finance [Member] \| Other Structured Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	4			4
Structured Finance [Member] \| Surveillance Category One [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	4			5
Structured Finance [Member] \| Surveillance Category One [Member] \| Mortgage-backed and Home Equity [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| Surveillance Category One [Member] \| Student Loan [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			1
Structured Finance [Member] \| Surveillance Category One [Member] \| Other Structured Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	4			4
Structured Finance [Member] \| IA [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			1
Structured Finance [Member] \| IA [Member] \| Mortgage-backed and Home Equity [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| IA [Member] \| Student Loan [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			1
Structured Finance [Member] \| IA [Member] \| Other Structured Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| II [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| II [Member] \| Mortgage-backed and Home Equity [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| II [Member] \| Student Loan [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| II [Member] \| Other Structured Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| III [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	7			7
Structured Finance [Member] \| III [Member] \| Mortgage-backed and Home Equity [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| III [Member] \| Student Loan [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	7			7
Structured Finance [Member] \| III [Member] \| Other Structured Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| IV [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	11			11
Structured Finance [Member] \| IV [Member] \| Mortgage-backed and Home Equity [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	11			11
Structured Finance [Member] \| IV [Member] \| Student Loan [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Structured Finance [Member] \| IV [Member] \| Other Structured Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Public Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	140			150
Public Finance [Member] \| Housing Revenue [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	139			148
Public Finance [Member] \| Other Public Finance Sectors [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	1			2
Public Finance [Member] \| Surveillance Category One [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	133			142
Public Finance [Member] \| Surveillance Category One [Member] \| Housing Revenue [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	131			140
Public Finance [Member] \| Surveillance Category One [Member] \| Other Public Finance Sectors [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	1			2
Public Finance [Member] \| IA [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	3			3
Public Finance [Member] \| IA [Member] \| Housing Revenue [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	3			3
Public Finance [Member] \| IA [Member] \| Other Public Finance Sectors [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Public Finance [Member] \| II [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	5			5
Public Finance [Member] \| II [Member] \| Housing Revenue [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	5			5
Public Finance [Member] \| II [Member] \| Other Public Finance Sectors [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Public Finance [Member] \| III [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Public Finance [Member] \| III [Member] \| Housing Revenue [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Public Finance [Member] \| III [Member] \| Other Public Finance Sectors [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Public Finance [Member] \| IV [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Public Finance [Member] \| IV [Member] \| Housing Revenue [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
Public Finance [Member] \| IV [Member] \| Other Public Finance Sectors [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	85			85
International Finance [Member] \| Sovereign/Sub-sovereign [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	64			64
International Finance [Member] \| Investor-owned and Public Utilities [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	18			18
International Finance [Member] \| Other International [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	3			2
International Finance [Member] \| Surveillance Category One [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	72			70
International Finance [Member] \| Surveillance Category One [Member] \| Sovereign/Sub-sovereign [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	51			49
International Finance [Member] \| Surveillance Category One [Member] \| Investor-owned and Public Utilities [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	18			18
International Finance [Member] \| Surveillance Category One [Member] \| Other International [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	3			2
International Finance [Member] \| IA [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	13			7
International Finance [Member] \| IA [Member] \| Sovereign/Sub-sovereign [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	13			7
International Finance [Member] \| IA [Member] \| Investor-owned and Public Utilities [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| IA [Member] \| Other International [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| II [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| II [Member] \| Sovereign/Sub-sovereign [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| II [Member] \| Investor-owned and Public Utilities [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| II [Member] \| Other International [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| III [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			9
International Finance [Member] \| III [Member] \| Sovereign/Sub-sovereign [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			9
International Finance [Member] \| III [Member] \| Investor-owned and Public Utilities [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| III [Member] \| Other International [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| IV [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| IV [Member] \| Sovereign/Sub-sovereign [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| IV [Member] \| Investor-owned and Public Utilities [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	0			0
International Finance [Member] \| IV [Member] \| Other International [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Premiums Receivable, Gross	$ 0			$ 0