XML 86 R34.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Business and Risks (Narrative) (Detail) (USD $) | 3 Months Ended |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Mar. 31, 2014 segments | Mar. 31, 2014 Mbia Inc [Member] | Dec. 31, 2013 Mbia Inc [Member] | Mar. 31, 2014 Mbia Inc General Corporate Purposes [Member] | Dec. 31, 2013 Mbia Inc General Corporate Purposes [Member] | Mar. 31, 2014 Asset Liability Products Segment [Member] | Dec. 31, 2013 Asset Liability Products Segment [Member]
Business Acquisition [Line Items] |  |  |  |  |  |  |
Number of operating segments | 3 |  |  |  |  |  |
Liquid assets |  | $ 499,000,000 | $ 359,000,000 | $ 443,000,000 | $ 307,000,000 | $ 56,000,000 | $ 52,000,000
Amount released from tax escrow account | 173,000,000 |  |  |  |  |  |
Commuted gross insured exposure | $ 3,800,000,000 |  |  |  |  |  |

X
- Definition This element represents the gross insured exposure commuted duting the period + References No definition available. + Details
Name: | mbi_CommutedGrossInsuredExposure
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition This element represents the liquidity position of the entity + References No definition available. + Details
Name: | mbi_LiquidAssets
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents the amount released from the escrow account related to the tax sharing agreement during the period + References No definition available. + Details
Name: | mbi_ReleaseFromTaxSharingAgreementEscrowAccount
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues. + References No definition available. + Details
Name: | us-gaap_NumberOfOperatingSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration