XML 90 R75.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Fair Value Of Financial Instruments (Gains And Losses On Fair Value Option Included In The Company's Consolidated Statements Of Operations) (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange |  | $ 63 |  | $ 78 |  | $ 69
Non Variable Interest Entity [Member] |  |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange |  | 63 |  | 78 |  | 69
Variable Interest Entity [Member] |  |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange |  | 42 |  | 50 |  | 175
Variable Interest Entity [Member] | Loan Repurchase Commitments [Member] |  |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | [1] | 17 |  | 20 |  | 172
Investments Carried At Fair Value [Member] | Non Variable Interest Entity [Member] |  |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | [2] | (3) |  | 2 |  | 8
Fixed Maturity Securities Held At Fair Value - VIE [Member] | Variable Interest Entity [Member] |  |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | [1] | (146) |  | (104) |  | (74)
Residential Mortgage Loans [Member] | Variable Interest Entity [Member] |  |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | [1] | (246) |  | (182) |  | (107)
Other Loans [Member] | Variable Interest Entity [Member] |  |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | [1] |  |  | 10 |  | 13
Medium Term Notes [Member] | Non Variable Interest Entity [Member] |  |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange |  | 36 | [2] | 6 | [2] | 38
Variable Interest Entity Notes [Member] | Variable Interest Entity [Member] |  |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | [1] | $ 381 |  | $ 269 |  | $ 155
[1] | Reported within Net gains (losses) of financial instruments at fair value and foreign exchange-VIE on MBIA's consolidated statements of operations.
[2] | Reported within Net gains (losses) of financial instruments at fair value and foreign exchange on MBIA's consolidated statements of operations.

X
- Definition Change in the fair value of and realized gains and losses on sale of financial instruments and foreign exchange included in earnings. + References No definition available. + Details
Name: | mbi_NetGainsLossesOnFinancialInstrumentsAtFairValueAndForeignExchange
Namespace Prefix: | mbi_
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_AccountsNotesAndLoansReceivableLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=us-gaap_ConsolidatedEntityExcludingVariableInterestEntitiesVIEMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=mbi_LoanRepurchaseCommitmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ScheduleOfFairValueOfSeparateAccountsByMajorCategoryOfInvestmentAxis=mbi_InvestmentsCarriedAtFairValueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ScheduleOfFairValueOfSeparateAccountsByMajorCategoryOfInvestmentAxis=mbi_FixedMaturitySecuritiesHeldAtFairValueVieMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ScheduleOfFairValueOfSeparateAccountsByMajorCategoryOfInvestmentAxis=mbi_ResidentialMortgageLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ScheduleOfFairValueOfSeparateAccountsByMajorCategoryOfInvestmentAxis=mbi_OtherLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_ScheduleOfFairValueOfSeparateAccountsByMajorCategoryOfInvestmentAxis=mbi_VariableInterestEntityNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |