XML 160 R126.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Pension And Profit Sharing Plans (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009
Defined Contribution Pension [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Contribution percentage of eligible employees compensation | 10.00% |  |
Vested after two years | 20.00% |  |
Vested after three years | 60.00% |  |
Vested after four years | 80.00% |  |
Vested after five years | 100.00% |  |
Pension expense | $ 6 | $ 7 | $ 6
Qualified Profit-Sharing/401(k) Plan [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Vested after two years | 20.00% |  |
Vested after three years | 60.00% |  |
Vested after four years | 80.00% |  |
Vested after five years | 100.00% |  |
Pension expense | 4 | 3 | 3
Non-Qualified Pension Expense [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Pension expense | 2 | 3 | 2
Non-Qualified Profit-Sharing/401(k) Expense [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Pension expense | $ 1 | $ 1 | $ 1
Maximum [Member] | Qualified Profit-Sharing/401(k) Plan [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Contribution percentage of eligible employees compensation | 25.00% |  |
Company match of employee contributions | 5.00% |  |

X
- Definition Contributions, Percentage of Employer Match + References No definition available. + Details
Name: | mbi_ContributionsPercentageOfEmployerMatch
Namespace Prefix: | mbi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of contributions towards employee's annual compensation. + References No definition available. + Details
Name: | mbi_PercentageOfContributionsTowardsEmployeesAnnualCompensation
Namespace Prefix: | mbi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of pension benefits vested due after five years. + References No definition available. + Details
Name: | mbi_PercentageOfPensionBenefitsVestedDueAfterFiveYears
Namespace Prefix: | mbi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of pension benefits vested due after four years. + References No definition available. + Details
Name: | mbi_PercentageOfPensionBenefitsVestedDueAfterFourYears
Namespace Prefix: | mbi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of pension benefits vested due after three years. + References No definition available. + Details
Name: | mbi_PercentageOfPensionBenefitsVestedDueAfterThreeYears
Namespace Prefix: | mbi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of pension benefits vested due after two years. + References No definition available. + Details
Name: | mbi_PercentageOfPensionBenefitsVestedDueAfterTwoYears
Namespace Prefix: | mbi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of pension benefit costs recognized during the period for (1) defined benefit plans and (2) defined contribution plans. For defined benefit plans, pension expense includes the following components: service cost, interest cost, expected return on plan assets, gain (loss) on plan assets, prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments. For defined contribution plans, the pension expense generally equals the firm's contribution to employees' accounts (if the firm contributes) during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 70 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph h -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5, 11 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 + Details
Name: | us-gaap_PensionExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration