XML 49 R40.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Loss And Loss Adjustment Expense Reserves (Loss And LAE Activity) (Narrative) (Detail) (USD $) | 3 Months Ended | 9 Months Ended |  |  |  |  |  |  |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 Abs Cdo Portfolio [Member] | Sep. 30, 2014 Second Lien Residential Mortgage Backed Securities And Reserves [Member] | Sep. 30, 2014 First Lien Residential Mortgage Backed Securities [Member] | Sep. 30, 2014 Financial Guarantee [Member] | Dec. 31, 2013 Financial Guarantee [Member] | Sep. 30, 2014 Financial Guarantee [Member] Variable Interest Entity Primary Beneficiary [Member] | Dec. 31, 2013 Financial Guarantee [Member] Variable Interest Entity Primary Beneficiary [Member] | Sep. 30, 2014 Loss And Lae Reserves [Member] | Dec. 31, 2013 Loss And Lae Reserves [Member] | Sep. 30, 2014 Recoveries On Unpaid Losses [Member] | Dec. 31, 2013 Recoveries On Unpaid Losses [Member] | Sep. 30, 2014 Insurance Loss Recoverable [Member] | Dec. 31, 2013 Insurance Loss Recoverable [Member] | Sep. 30, 2014 Insurance Loss Recoverable [Member] Classified [Member] | Dec. 31, 2013 Insurance Loss Recoverable [Member] Classified [Member] | Sep. 30, 2014 Loan Repurchase Commitments [Member] Second Lien Residential Mortgage Backed Securities And Reserves [Member] Ineligible Loan Recoveries [Member] | Dec. 31, 2013 Loan Repurchase Commitments [Member] Second Lien Residential Mortgage Backed Securities And Reserves [Member] Ineligible Loan Recoveries [Member]
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
ABS CDO exposure decrease since December 31,2007 |  |  |  |  | 97.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate ABS CDO Loss And LAE Reserves |  |  |  |  |  |  |  | $ 72,000,000 | $ 115,000,000 | $ 243,000,000 | $ 226,000,000 |  |  |  |  |  |  |  |  |  |
Policyholder (Benefits) And Claims Incurred Net | 20,000,000 | 98,000,000 | 82,000,000 | 92,000,000 | (14,000,000) | 88,000,000 | 39,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Elimination Of Loss And LAE Expense (Benefit) As Result Of Consolidating VIE |  |  |  |  | 17,000,000 | 25,000,000 | (1,000,000) |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reserves for expected future claim payments |  |  |  |  |  |  |  |  |  |  |  | 612,000,000 | 847,000,000 |  |  |  |  |  |  |  |
Expected recoveries of future payments |  |  |  |  |  |  |  |  |  |  |  | 95,000,000 | 206,000,000 | 95,000,000 | 206,000,000 |  |  |  |  |  |
Weighted average risk-free rate used to discount claim liability |  |  | 2.01% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total estimated insurance recoveries |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 365,000,000 | 359,000,000
Insurance claim loss recoverable |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 568,000,000 | 694,000,000 |  |
Insurance loss recoverable |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 575,000,000 | 694,000,000 | 575,000,000 | 694,000,000 |  |
Losses and LAE related to expected payments |  |  | $ (56,000,000) |  |  | $ 13,000,000 | $ 43,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition ABS CDO exposure decrease. + References No definition available. + Details
Name: | mbi_AbsCdoExposureDecrease
Namespace Prefix: | mbi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate ABS CDO loss and LAE reserves. + References No definition available. + Details
Name: | mbi_AggregateAbsCdoLossAndLaeReserves
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Elimination Of Loss And LAE Expense As Result Of Consolidating VIEs + References No definition available. + Details
Name: | mbi_EliminationOfLossAndLaeExpenseAsResultOfConsolidatingVie
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Gross reserve, recoveries on unpaid losses + References No definition available. + Details
Name: | mbi_GrossReserveRecoveriesOnUnpaidLosses
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of paid insurance policy claims and LAE expense expected to be recovered. + References No definition available. + Details
Name: | mbi_InsuranceLossRecoverable
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | mbi_LossAndLossAdjustmentExpenseReservesLineItems
Namespace Prefix: | mbi_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Losses And Loss Adjustment Expenses Related To Actual And Expected Payments + References No definition available. + Details
Name: | mbi_LossesAndLossAdjustmentExpensesRelatedToActualAndExpectedPayments
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Reserves For Expected Future Claim Payments + References No definition available. + Details
Name: | mbi_ReservesForExpectedFutureClaimPayments
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Total Estimated Insurance Recoveries + References No definition available. + Details
Name: | mbi_TotalEstimatedInsuranceRecoveries
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of amounts expected to be recovered under the terms of insurance contracts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 + Details
Name: | us-gaap_EstimatedInsuranceRecoveries
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents the weighted average risk free rate used to discount the claim liability related to financial guarantee insurance contracts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 9 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6933314&loc=SL5749324-161292 + Details
Name: | us-gaap_FinancialGuaranteeInsuranceContractsClaimLiabilityWeightedAverageRiskFreeDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after effects of policies assumed or ceded, of expense related to the provision for policy benefits and costs incurred. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.5) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 5 -Article 7 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 20 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6480758&loc=d3e6811-158387 + Details
Name: | us-gaap_PolicyholderBenefitsAndClaimsIncurredNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration