XML 99 R88.htm IDEA: XBRL DOCUMENT v3.25.0.1

Income Taxes (Narrative) (Detail) $ in Millions	Aug. 16, 2022	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Non Variable Interest Entities [Line Items]
NOL carryforward		$ 4,400
Foreign tax credit		55	$ 56
Unrecognized Tax Benefits		0	0
Valuation allowance on net deferred tax asset		$ 1,380	$ 1,245
Effective income tax rate reconciliation, alternative minimum tax on the book income of large corporations, percent	15
Effective income tax rate reconciliation, excise tax on most stock buybacks, percent.	1

X

- Definition

Effective income tax rate reconciliation, alternative minimum tax on the book income of large corporations, percent.

+ References

No definition available.

+ Details

Name:	mbi_EffectiveIncomeTaxRateReconciliationAlternativeMinimumTaxOnTheBookIncomeOfLargeCorporationsPercent
Namespace Prefix:	mbi_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Effective income tax rate reconciliation, excise tax on most stock buybacks, percent.

+ References

No definition available.

+ Details

Name:	mbi_EffectiveIncomeTaxRateReconciliationExciseTaxOnMostStockBuybacksPercent
Namespace Prefix:	mbi_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Non-Variable Interest Entities [Line Items]

+ References

No definition available.

+ Details

Name:	mbi_NonVariableInterestEntitiesLineItems
Namespace Prefix:	mbi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible foreign tax credit carryforwards.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-6

+ Details

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

X

- Definition

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

+ Details

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

X

- Definition

Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-3

+ Details

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

X

- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 217
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-217

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-15A

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 10B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482525/740-10-45-10B

+ Details

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