XML 53 R42.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Loss And Loss Adjustment Expense Reserves (Schedule Of Insurance Loss Recoverable And Changes In Recoveries On Unpaid Losses) (Detail) $ in Millions | 6 Months Ended
--- | ---
Jun. 30, 2016 USD ($)
Loss And Loss Adjustment Expense Recoveries [Line Items] |  |
Gross Reserve beginning balance, Insurance loss recoverable | $ 577 |
Gross Reserve ending balance, Insurance loss recoverable | 365 |
Insurance Loss Recoverable [Member] |  |
Loss And Loss Adjustment Expense Recoveries [Line Items] |  |
Gross Reserve beginning balance, Insurance loss recoverable | 577 |
Collections for Cases with Recoveries | (50) |
Accretion of Recoveries | 3 |
Changes in Discount Rates | 10 |
Changes in Assumptions | (126) |
Changes in LAE Recoveries | (4) |
Other | (45) | [1]
Gross Reserve ending balance, Insurance loss recoverable | 365 |
Recoveries On Unpaid Losses [Member] |  |
Loss And Loss Adjustment Expense Recoveries [Line Items] |  |
Gross Reserve beginning balance,Recoveries on unpaid losses | 100 |
Collections for Cases with Recoveries | 0 |
Accretion of Recoveries | 1 |
Changes in Discount Rates | 9 |
Changes in Assumptions | (24) |
Changes in LAE Recoveries | 5 |
Other | 0 | [1]
Gross Reserve ending balance, Recoveries on unpaid losses | 91 |
Insurance Loss Recoverable And Changes In Recoveries On Unpaid Losses [Member] |  |
Loss And Loss Adjustment Expense Recoveries [Line Items] |  |
Gross Reserve beginning balance, Total | 677 |
Collections for Cases with Recoveries | (50) |
Accretion of Recoveries | 4 |
Changes in Discount Rates | 19 |
Changes in Assumptions | (150) |
Changes in LAE Recoveries | 1 |
Other | (45) | [1]
Gross Reserve ending balance, Total | $ 456 |
[1] | Primarily changes in amount and timing of collections.

X
- Definition Cash receipts related to recoveries of previously paid claims + References No definition available. + Details
Name: | mbi_CollectionsForCasesWithRecoveries
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 Increase Decrease In Loss Adjustment Expense Recoveries + References No definition available. + Details
Name: | mbi_IncreaseDecreaseInLossAdjustmentExpenseRecoveries
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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
- Definition Insurance loss recoverable and changes in recoveries of unpaid losses. + References No definition available. + Details
Name: | mbi_InsuranceLossRecoverableAndChangesInRecoveriesOfUnpaidLosses
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Insurance Loss Recoverable And Changes In Recoveries Of Unpaid Losses Accretion Of Recoveries + References No definition available. + Details
Name: | mbi_InsuranceLossRecoverableAndChangesInRecoveriesOfUnpaidLossesAccretionOfRecoveries
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Insurance Loss Recoverable And Changes In Recoveries Of Unpaid Losses Change In Assumptions + References No definition available. + Details
Name: | mbi_InsuranceLossRecoverableAndChangesInRecoveriesOfUnpaidLossesChangeInAssumptions
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Insurance Loss Recoverable And Changes In Recoveries Of Unpaid Losses Change In Discount Rate + References No definition available. + Details
Name: | mbi_InsuranceLossRecoverableAndChangesInRecoveriesOfUnpaidLossesChangeInDiscountRate
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Changes in the timing and amount of net collections on financial guarantee contracts. + References No definition available. + Details
Name: | mbi_InsuranceLossRecoverableAndChangesInRecoveriesOfUnpaidLossesOther
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Loss And Loss Adjustment Expense Recoveries [Line Items] + References No definition available. + Details
Name: | mbi_LossAndLossAdjustmentExpenseRecoveriesLineItems
Namespace Prefix: | mbi_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | mbi_ClaimLiabilityAxis=mbi_InsuranceLossRecoverableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | mbi_ClaimLiabilityAxis=mbi_RecoveriesOnUnpaidLossesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=mbi_InsuranceLossRecoverableAndChangesInRecoveriesOnUnpaidLossesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |