XML 105 R89.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Derivative Instruments (Effect Of Derivative Instruments On Consolidated Statements Of Operations) (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Derivative [Line Items] |  |  |
Net gain/(loss) recognized in income | $ (15) | $ 69 | $ 398
Unrealized Gains Losses On Insured Derivatives [Member] | Credit Default Swap [Member] |  |  |
Derivative [Line Items] |  |  |
Net gain/(loss) recognized in income | 21 | 157 | 888
Unrealized Gains Losses On Insured Derivatives [Member] | All Other [Member] |  |  |
Derivative [Line Items] |  |  |
Net gain/(loss) recognized in income | 0 | 0 | 15
Realized Gains Losses And Other Settlements On Insured Derivatives [Member] | Credit Default Swap [Member] |  |  |
Derivative [Line Items] |  |  |
Net gain/(loss) recognized in income | (40) | (28) | (413)
Realized Gains Losses And Other Settlements On Insured Derivatives [Member] | All Other [Member] |  |  |
Derivative [Line Items] |  |  |
Net gain/(loss) recognized in income | 0 | 0 | (31)
Foreign Exchange And Other Derivative Financial Instruments [Member] | Interest Rate Swap [Member] |  |  |
Derivative [Line Items] |  |  |
Net gain/(loss) recognized in income | (11) | (108) | (78)
Foreign Exchange And Other Derivative Financial Instruments [Member] | All Other [Member] |  |  |
Derivative [Line Items] |  |  |
Net gain/(loss) recognized in income | (2) | 7 | 6
Foreign Exchange And Other Derivative Financial Instruments Attributable To V I E [Member] | Interest Rate Swaps V I E [Member] |  |  |
Derivative [Line Items] |  |  |
Net gain/(loss) recognized in income | 8 | 31 | 0
Foreign Exchange And Other Derivative Financial Instruments Attributable To V I E [Member] | Currency Swaps Vie [Member] |  |  |
Derivative [Line Items] |  |  |
Net gain/(loss) recognized in income | $ 9 | $ 10 | $ 11

X
- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5618551-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (a),(c),(d),(e) -URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624171-113959 + Details
Name: | us-gaap_DerivativeGainLossOnDerivativeNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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_IncomeStatementLocationAxis=mbi_UnrealizedGainsLossesOnInsuredDerivativesMember
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=us-gaap_OtherCreditDerivativesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=mbi_RealizedGainsLossesAndOtherSettlementsOnInsuredDerivativesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_ForeignExchangeAndOtherDerivativeFinancialInstrumentsMember
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_IncomeStatementLocationAxis=mbi_ForeignExchangeAndOtherDerivativeFinancialInstrumentsAttributableToVIEMember
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_DerivativeInstrumentRiskAxis=mbi_CurrencySwapsVieMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |