XML 34 R67.htm IDEA: XBRL DOCUMENT
v3.3.0.814

Derivative Instruments (Total Fair Value Of Company's Derivative Assets And Liabilities By Instrument And Balance Sheet Location, Before Counterparty Netting) (Detail) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Millions | Sep. 30, 2015 | Dec. 31, 2014
--- | --- | ---
Derivative [Line Items] |  |  |
Derivative notional amount |  | $ 10,027 | $ 15,839
Derivative Liabilities [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Liabilities, Not designated, Fair Value | [1] | (473) | (537)
Derivative Assets [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Assets, Not designated, Fair Value | [1] | 16 | 91
Interest Rate Swap [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative notional amount |  | 1,155 | 1,450
Interest Rate Swap [Member] | Derivative Liabilities [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Liabilities, Not designated, Fair Value | [1] | (255) | (248)
Interest Rate Swap [Member] | Other Assets [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Assets, Not designated, Fair Value | [1] | 4 | 83
Credit Default Swap [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative notional amount |  | 3,318 | 9,481
Credit Default Swap [Member] | Derivative Liabilities [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Liabilities, Not designated, Fair Value | [1] | (121) | (244)
Insured Swaps [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative notional amount |  | 3,828 | 4,044
Insured Swaps [Member] | Derivative Liabilities [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Liabilities, Not designated, Fair Value | [1] | (3) | (2)
Interest Rate Swaps V I E [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative notional amount |  | 903 |
Interest Rate Swaps V I E [Member] | Derivative Liabilities V I E [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Liabilities, Not designated, Fair Value |  | (57) |
Interest Rate Swaps V I E [Member] | Derivative Assets V I E [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Assets, Not designated, Fair Value |  | 0 |
Interest Rate Swaps Embedded [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative notional amount |  | 406 | 437
Interest Rate Swaps Embedded [Member] | Medium Term Notes [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Assets, Not designated, Fair Value | [1] | 6 | 8
Derivative Liabilities, Not designated, Fair Value | [1] | (15) | (19)
Currency Swaps Vie [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative notional amount |  | 81 | 91
Currency Swaps Vie [Member] | Derivative Assets V I E [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Assets, Not designated, Fair Value |  | 6 |
All Other [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative notional amount |  | 83 | 83
All Other [Member] | Derivative Liabilities [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative Liabilities, Not designated, Fair Value | [1] | (22) | (24)
All Other V I E [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative notional amount |  | 241 | 241
All Other Embedded [Member] |  |  |
Derivative [Line Items] |  |  |
Derivative notional amount |  | $ 12 | $ 12
[1] | In accordance with the accounting guidance for derivative instruments and hedging activities, the balance sheet location of the Company's embedded derivative instruments is determined by the location of the related host contract

X
- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
Name: | invest_DerivativeNotionalAmount
Namespace Prefix: | invest_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fair value of derivative Asset Not Designated As Hedging Instrument, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position. + References No definition available. + Details
Name: | mbi_DerivativeAssetsNotDesignatedAsHedgingInstrumentFairValue
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of derivative liability Not Designated As Hedging Instrument, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position. + References No definition available. + Details
Name: | mbi_DerivativeLiabilitiesNotDesignatedAsHedgingInstrumentFairValue
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- 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 No definition available. + Details
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=mbi_DerivativeLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=mbi_DerivativeAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CreditDefaultSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=mbi_InsuredSwapsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=mbi_InterestRateSwapsVIEMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=mbi_DerivativeLiabilitiesVIEMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=mbi_DerivativeAssetsVIEMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=mbi_InterestRateSwapsEmbeddedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_MediumTermNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=mbi_CurrencySwapsVieMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=mbi_AllOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=mbi_AllOtherVIEMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=mbi_AllOtherEmbeddedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |