Debt instrument maturity year.

No definition available.

Name:	mbi_DebtInstrumentMaturityYear
Namespace Prefix:	mbi_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the liquidity position of the entity

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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+ Details

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Balance Type:	na
Period Type:	duration

- Definition

This element represents disclosure of the aggregate cash dividends paid to the entity by consolidated subsidiaries.

+ References

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

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Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

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+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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Balance Type:	na
Period Type:	instant

- Definition

Face (par) amount of the original debt instrument that was repurchased.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of right to receive securities collateral under master netting arrangements that have not been offset against derivative liabilities.

+ References

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+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Date the declared dividend will be paid, in YYYY-MM-DD format.

+ References

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+ Details

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Balance Type:	na
Period Type:	duration

- Definition

The aggregate fair value as of the balance sheet date of financial instruments and other positions owned by the entity including: (1) mortgages, mortgage-backed and asset backed securities; (2) US government and agency obligations; (3) state and municipal government obligations; (4) other sovereign government debt; (5) corporate obligations; (6) corporate equities; (7) principal investments; (8) derivative contracts; and (9) physical commodities. Includes both pledged and unpledged holdings.

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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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- Details

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- Details

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- Details

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Schedule II - (Notes to Condensed Financial Statements) (Detail) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Dec. 07, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Condensed Financial Statements, Captions [Line Items]
Long-term debt principal amount purchased		$ 308
Securities posted as collateral to derivative counterparties			$ 73
Dividend declared per common share	$ 8
Dividend payment date		Dec. 22, 2023
Mbia Inc. Debentures [Member]
Condensed Financial Statements, Captions [Line Items]
Long-term debt, interest rate		7.00%
Long-term debt, maturity year		2025
MBIA Inc. Senior Notes [Member]
Condensed Financial Statements, Captions [Line Items]
Long-term debt, interest rate		5.70%
Long-term debt, maturity year		2034
6.625% Senior Notes due 2028 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt Instrument, Face Amount		$ 29	$ 24
Long-term debt, interest rate		6.625%	6.625%
Long-term debt, maturity year		2028	2028
7.15% Senior Notes due 2027 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt Instrument, Face Amount		$ 5	$ 4
Long-term debt, interest rate		7.15%	7.15%
Long-term debt, maturity year		2027	2027
7.00% Senior Notes due 2025 [Member]
Condensed Financial Statements, Captions [Line Items]
Debt Instrument, Face Amount		$ 1	$ 1
Long-term debt, interest rate		7.00%	7.00%
Long-term debt, maturity year		2025	2025
MBIA Corp Surplus Notes [Member] \| Mbia Inc. Debentures [Member]
Condensed Financial Statements, Captions [Line Items]
Long-term debt principal amount purchased		$ 13
MBIA Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Liquid assets		411
Fair value of securities pledged as collateral		$ 241	$ 251
Securities posted as collateral to derivative counterparties			73
Dividend declared per common share	$ 8
Dividend payment date		Dec. 22, 2023
National [Member]
Condensed Financial Statements, Captions [Line Items]
Dividends from subsidiaries			$ 72	$ 60
National [Member] \| Special Dividend [Member]
Condensed Financial Statements, Captions [Line Items]
Dividends from subsidiaries		$ 550
National [Member] \| Right Dividend [Member]
Condensed Financial Statements, Captions [Line Items]
Dividends from subsidiaries		97
National [Member] \| Mbia Inc. Debentures [Member]
Condensed Financial Statements, Captions [Line Items]
Long-term debt principal amount purchased		10
National [Member] \| MBIA Inc. Senior Notes [Member] \| Mbia Inc. Debentures [Member]
Condensed Financial Statements, Captions [Line Items]
Long-term debt principal amount purchased		$ 10