XML 125 R109.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Insurance Regulations And Dividends (Narrative) (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2016 | Dec. 31, 2015
Insurance Regulations And Dividends [Line Items] |  |
Percentage of policyholders' surplus | 10.00% |
Percentage of adjusted net investment income | 100.00% |
Dividends from subsidiaries | $ 118 | $ 114
Minimum [Member] |  |
Insurance Regulations And Dividends [Line Items] |  |
Policyholders' surplus | 65 |
MBIA Corp [Member] |  |
Insurance Regulations And Dividends [Line Items] |  |
Statutory net loss | 323 |
Statutory capital | 492 | 885
Policyholders' surplus | 238 |
Contingency reserves | $ 254 |
Statutory net income |  | 25
MBIA Corp [Member] | Loss Reserves And Unearned Premium Reserves [Member] |  |
Insurance Regulations And Dividends [Line Items] |  |
Percentage of loss reserves and unearned premium reserve required to be invested in qualifying assets | 50.00% |
MBIA Corp [Member] | Policyholders Surplus [Member] |  |
Insurance Regulations And Dividends [Line Items] |  |
Unassigned surplus | $ (1,800) | (1,400)
Statutory surplus negative impact | $ 112 | 75
Maximum percentage of statutory net admitted assets invested in subsidiaries | 60.00% |
National [Member] |  |
Insurance Regulations And Dividends [Line Items] |  |
Statutory capital | $ 3,500 | 3,400
Policyholders' surplus | 2,700 |
Contingency reserves | 745 |
Statutory net income | 192 | $ 284
MBIA UK [Member] |  |
Insurance Regulations And Dividends [Line Items] |  |
Loss recorded on adjustment of carrying value to fair value less costs to sell | $ 114 |

X
- Definition Insurance Regulations And Dividends Line Items + References No definition available. + Details
Name: | mbi_InsuranceRegulationsAndDividendsLineItems
Namespace Prefix: | mbi_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage required to be invested in certain qualifing assets. + References No definition available. + Details
Name: | mbi_InvestmentsInCertainQualifingAssets
Namespace Prefix: | mbi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum percentage of statutory admitted assets allowed to be invested in subsidaries under New York insurance laws. + References No definition available. + Details
Name: | mbi_MaximumPercentageOfStatutoryAdmittedAssetsInvestedInSubsidiaries
Namespace Prefix: | mbi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of adjusted net investment income. + References No definition available. + Details
Name: | mbi_PercentageOfAdjustedNetInvestmentIncome
Namespace Prefix: | mbi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage Of Policyholders Surplus + References No definition available. + Details
Name: | mbi_PercentageOfPolicyholdersSurplus
Namespace Prefix: | mbi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Statutory Accounting Practices defined as policyholders' surplus plus contingency reserves. + References No definition available. + Details
Name: | mbi_StatutoryAccountingPracticesCapital
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Statutory accounting practices, contingency reserves. + References No definition available. + Details
Name: | mbi_StatutoryAccountingPracticesContingencyReserves
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of net loss for the period determined using accounting principles prescribed or permitted by insurance regulators. + References No definition available. + Details
Name: | mbi_StatutoryAccountingPracticesStatutoryNetLossAmount
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Statutory accounting practices, surplus. + References No definition available. + Details
Name: | mbi_StatutoryAccountingPracticesSurplus
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Statutory accounting practices, unassigned surplus. + References No definition available. + Details
Name: | mbi_StatutoryAccountingPracticesUnassignedSurplus
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Impact on statutory surplus due to maximum amount of investment in subsidiaries. + References No definition available. + Details
Name: | mbi_StatutorySurplusNegativeImpact
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents disclosure of the aggregate cash dividends paid to the entity by consolidated subsidiaries. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04.(b)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 235 -Section S99 -Paragraph 2 -Subparagraph (SX 210.9-06) -URI http://asc.fasb.org/extlink&oid=6882215&loc=d3e537971-122884 + Details
Name: | us-gaap_CashDividendsPaidToParentCompanyByConsolidatedSubsidiaries
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of gain (loss) on sale or disposal of equity in securities of subsidiaries. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (13)(g) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 + Details
Name: | us-gaap_GainOrLossOnSaleOfStockInSubsidiary
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of net income for the period determined using accounting principles prescribed or permitted by insurance regulators. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.23(c)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 24 -Subparagraph c -Article 7 + Details
Name: | us-gaap_StatutoryAccountingPracticesStatutoryNetIncomeAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=mbi_LossReservesAndUnearnedPremiumReservesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=mbi_PolicyholdersSurplusMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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