XML 19 R46.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Loss And Loss Adjustment Expense Reserves (Schedule Of Insurance Loss Recoverable And Changes In Recoveries On Unpaid Losses) (Detail) (USD $) In Millions, unless otherwise specified | 9 Months Ended
--- | ---
Sep. 30, 2014
Loss And Loss Adjustment Expense Recoveries [Line Items] |  |
Gross Reserve beginning balance, Total | $ 900 |
Collections for Cases with Recoveries | (84) |
Accretion of Recoveries | 13 |
Changes in Discount Rates | 22 |
Changes in Assumptions | (191) |
Changes in LAE Recoveries | 9 |
Other | 1 | [1]
Gross Reserve ending balance, Total | 670 |
Insurance Loss Recoverable [Member] |  |
Loss And Loss Adjustment Expense Recoveries [Line Items] |  |
Gross Reserve beginning balance, Insurance loss recoverable | 694 |
Collections for Cases with Recoveries | (84) |
Accretion of Recoveries | 10 |
Changes in Discount Rates | 10 |
Changes in Assumptions | (63) |
Changes in LAE Recoveries | 7 |
Other | 1 | [1]
Gross Reserve ending balance, Insurance loss recoverable | 575 |
Recoveries On Unpaid Losses [Member] |  |
Loss And Loss Adjustment Expense Recoveries [Line Items] |  |
Gross Reserve beginning balance,Recoveries on unpaid losses | 206 |
Collections for Cases with Recoveries | 0 |
Accretion of Recoveries | 3 |
Changes in Discount Rates | 12 |
Changes in Assumptions | (128) |
Changes in LAE Recoveries | 2 |
Other | 0 | [1]
Gross Reserve ending balance, Recoveries on unpaid losses | $ 95 |
[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
- Details
Name: | mbi_LossAndLossAdjustmentExpenseRecoveriesLineItems
Namespace Prefix: | mbi_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration