XML 23 R70.htm IDEA: XBRL DOCUMENT v2.4.1.9

Loss And Loss Adjustment Expense Reserves (Schedule Of Expenses Related To Remedial Actions For Insured Obligations) (Detail) (Remedial Actions For Insured Obligations [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Remedial Actions For Insured Obligations [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Loss adjustment expense incurred, gross	$ 36us-gaap_PolicyholderBenefitsAndClaimsIncurredGross / mbi_ClaimLiabilityAxis = mbi_RemedialActionsForInsuredObligationsMember	$ 57us-gaap_PolicyholderBenefitsAndClaimsIncurredGross / mbi_ClaimLiabilityAxis = mbi_RemedialActionsForInsuredObligationsMember	$ 137us-gaap_PolicyholderBenefitsAndClaimsIncurredGross / mbi_ClaimLiabilityAxis = mbi_RemedialActionsForInsuredObligationsMember

X

- Details

Name:	mbi_LossAndLossAdjustmentExpenseReservesLineItems
Namespace Prefix:	mbi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount, before effect of policies assumed or ceded, of expense related to 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

+ Details

Name:	us-gaap_PolicyholderBenefitsAndClaimsIncurredGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration