XML 109 R95.htm IDEA: XBRL DOCUMENT
v3.20.4

Insurance in Force (Schedule Of Geographical Distribution Of Insurance In Force) (Detail) - USD ($) $ in Billions | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Insurance in Force | $ 91.4 | $ 107.5
% of Insurance in Force | 100.00% | 100.00%
California [Member] |  |
Insurance in Force | $ 20.0 | $ 22.4
% of Insurance in Force | 21.90% | 20.90%
Illinois [Member] |  |
Insurance in Force | $ 8.9 | $ 10.2
% of Insurance in Force | 9.70% | 9.50%
New York [Member] |  |
Insurance in Force | $ 3.0 | $ 4.7
% of Insurance in Force | 3.30% | 4.40%
Puerto Rico [Member] |  |
Insurance in Force | $ 2.9 | $ 3.3
% of Insurance in Force | 3.20% | 3.10%
New Jersey [Member] |  |
Insurance in Force | $ 5.4 | $ 6.0
% of Insurance in Force | 5.90% | 5.60%
Texas [Member] |  |
Insurance in Force | $ 3.7 | $ 4.0
% of Insurance in Force | 4.00% | 3.70%
Hawaii [Member] |  |
Insurance in Force | $ 4.1 | $ 4.2
% of Insurance in Force | 4.40% | 3.90%
Virginia [Member] |  |
Insurance in Force | $ 3.2 | $ 3.6
% of Insurance in Force | 3.60% | 3.30%
Oregon [Member] |  |
Insurance in Force | $ 2.7 | $ 2.9
% of Insurance in Force | 2.90% | 2.70%
Sub-Total Insurance In Force [Member] |  |
Insurance in Force | $ 56.0 | $ 64.1
% of Insurance in Force | 61.20% | 59.70%
Nationally Diversified [Member] |  |
Insurance in Force | $ 8.7 | $ 11.8
% of Insurance in Force | 9.50% | 11.00%
Other States [Member] |  |
Insurance in Force | $ 19.8 | $ 23.5
% of Insurance in Force | 21.70% | 21.80%
United States [Member] |  |
Insurance in Force | $ 84.5 | $ 99.4
% of Insurance in Force | 92.40% | 92.50%
Internationally Diversified [Member] |  |
Insurance in Force | $ 0.3 | $ 0.3
% of Insurance in Force | 0.30% | 0.30%
Country Specific [Member] |  |
Insurance in Force | $ 6.6 | $ 7.8
% of Insurance in Force | 7.30% | 7.20%
Non United States [Member] |  |
Insurance in Force | $ 6.9 | $ 8.1
% of Insurance in Force | 7.60% | 7.50%
COLORADO |  |
Insurance in Force | $ 2.1 | $ 2.8
% of Insurance in Force | 2.30% | 2.60%

X
- Definition Represents the gross outstanding insured contractual payments for each caterory as a percentage of the total outstanding insured contractual payments. + References No definition available. + Details
Name: | mbi_InsuredFinancialObligationsInsuredContractualPaymentsAsPercentageOfTotalInsuredContractualObligations
Namespace Prefix: | mbi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents the amount of insured contractual payments (principal and interest) outstanding on the underlying insured obligations for financial guaranty contracts, gross of ceded contracts. + References No definition available. + Details
Name: | mbi_InsuredFinancialObligationsInsuredContractualPaymentsOutstandingGross
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | srt_StatementGeographicalAxis=stpr_CA
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=stpr_IL
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=stpr_NY
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_PR
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=stpr_NJ
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=stpr_TX
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=stpr_HI
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=stpr_VA
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=stpr_OR
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=mbi_SubTotalInsuranceInForceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=mbi_NationallyDiversifiedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=mbi_OtherStatesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_US
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=mbi_InternationallyDiversifiedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=mbi_CountrySpecificMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=mbi_NonUnitedStatesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=stpr_CO
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |