XML 94 R49.htm IDEA: XBRL DOCUMENT
v2.4.0.6

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 |  |  | 6 Months Ended
--- | --- | --- | ---
Jun. 30, 2012 | Dec. 31, 2011 | Jun. 30, 2012 Insurance Loss Recoverable And Changes In Recoveries On Unpaid Losses [Member] | Jun. 30, 2012 Insurance Loss Recoverable And Changes In Recoveries On Unpaid Losses [Member] Insurance Loss Recoverable [Member] | Jun. 30, 2012 Insurance Loss Recoverable And Changes In Recoveries On Unpaid Losses [Member] Recoveries On Unpaid Losses [Member]
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |  |
Gross Reserve beginning balance, Insurance loss recoverable | $ 3,212 | $ 3,046 |  |  |
Gross Reserve beginning balance,Recoveries on unpaid losses | 508 | 562 |  |  |
Gross Reserve beginning balance, Total | 3,720 | 3,608 |  |  |
Gross Reserve ending balance, Insurance loss recoverable | 3,212 | 3,046 |  |  |
Gross Reserve ending balance, Recoveries on unpaid losses | 508 | 562 |  |  |
Gross Reserve ending balance, Total | 3,720 | 3,608 |  |  |
Collections for Cases with Recoveries |  |  | (4) | (4) |
Accretion of Recoveries |  |  | 25 | 21 | 4
Changes in Discount Rates |  |  | 26 | 9 | 17
Changes in Timing of Collections |  |  |  |  |
Changes in Amount of Collections |  |  | (130) | (130) |
Changes in Assumptions |  |  | 186 | 257 | (71)
Changes in LAE Recoveries |  |  | $ 9 | $ 13 | $ (4)

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 Collections + References No definition available. + Details
Name: | mbi_InsuranceLossRecoverableAndChangesInRecoveriesOfUnpaidLossesChangeInCollections
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 Insurance Loss Recoverable And Changes In Recoveries Of Unpaid Losses Change In Timing + References No definition available. + Details
Name: | mbi_InsuranceLossRecoverableAndChangesInRecoveriesOfUnpaidLossesChangeInTiming
Namespace Prefix: | mbi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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