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Variable Interest Entities (Summary Of Nonconsolidated VIEs Assets And Liabilities) (Detail) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | ---
Variable Interest Entity [Line Items] |  |  |
Maximum Exposure to Loss |  | $ 7,284 | $ 8,985
Investments [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [1] | 17 | 19
Premiums Receivable [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [2] | 40 | 49
Insurance Loss Recoverable [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [3] | 987 | 173
Unearned Premium Revenue [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Liabilities | [4] | 41 | 51
Loss And Loss Adjustment Expense Reserves Member [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Liabilities | [5] | 357 | 406
Global Structured Finance [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Maximum Exposure to Loss |  | 5,053 | 6,461
Global Structured Finance [Member] | Investments [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [1] | 17 | 19
Global Structured Finance [Member] | Premiums Receivable [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [2] | 31 | 39
Global Structured Finance [Member] | Insurance Loss Recoverable [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [3] | 987 | 173
Global Structured Finance [Member] | Unearned Premium Revenue [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Liabilities | [4] | 29 | 37
Global Structured Finance [Member] | Loss And Loss Adjustment Expense Reserves Member [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Liabilities | [5] | 357 | 406
Global Structured Finance [Member] | Residential Mortgage Backed Securities [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Maximum Exposure to Loss |  | 3,103 | 3,741
Global Structured Finance [Member] | Residential Mortgage Backed Securities [Member] | Investments [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [1] | 17 | 19
Global Structured Finance [Member] | Residential Mortgage Backed Securities [Member] | Premiums Receivable [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [2] | 19 | 22
Global Structured Finance [Member] | Residential Mortgage Backed Securities [Member] | Insurance Loss Recoverable [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [3] | 128 | 172
Global Structured Finance [Member] | Residential Mortgage Backed Securities [Member] | Unearned Premium Revenue [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Liabilities | [4] | 17 | 20
Global Structured Finance [Member] | Residential Mortgage Backed Securities [Member] | Loss And Loss Adjustment Expense Reserves Member [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Liabilities | [5] | 345 | 396
Global Structured Finance [Member] | Commercial Mortgage Backed Securities [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Maximum Exposure to Loss |  | 52 | 94
Global Structured Finance [Member] | Commercial Mortgage Backed Securities [Member] | Investments [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [1] | 0 | 0
Global Structured Finance [Member] | Commercial Mortgage Backed Securities [Member] | Premiums Receivable [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [2] | 0 | 0
Global Structured Finance [Member] | Commercial Mortgage Backed Securities [Member] | Insurance Loss Recoverable [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [3] | 0 | 0
Global Structured Finance [Member] | Commercial Mortgage Backed Securities [Member] | Unearned Premium Revenue [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Liabilities | [4] | 0 | 0
Global Structured Finance [Member] | Commercial Mortgage Backed Securities [Member] | Loss And Loss Adjustment Expense Reserves Member [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Liabilities | [5] | 0 | 0
Global Structured Finance [Member] | Consumer Asset Backed [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Maximum Exposure to Loss |  | 560 | 981
Global Structured Finance [Member] | Consumer Asset Backed [Member] | Investments [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [1] | 0 | 0
Global Structured Finance [Member] | Consumer Asset Backed [Member] | Premiums Receivable [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [2] | 3 | 4
Global Structured Finance [Member] | Consumer Asset Backed [Member] | Insurance Loss Recoverable [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [3] | 1 | 1
Global Structured Finance [Member] | Consumer Asset Backed [Member] | Unearned Premium Revenue [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Liabilities | [4] | 2 | 3
Global Structured Finance [Member] | Consumer Asset Backed [Member] | Loss And Loss Adjustment Expense Reserves Member [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Liabilities | [5] | 12 | 10
Global Structured Finance [Member] | Corporate Asset Backed [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Maximum Exposure to Loss |  | 1,338 | 1,645
Global Structured Finance [Member] | Corporate Asset Backed [Member] | Investments [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [1] | 0 | 0
Global Structured Finance [Member] | Corporate Asset Backed [Member] | Premiums Receivable [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [2] | 9 | 13
Global Structured Finance [Member] | Corporate Asset Backed [Member] | Insurance Loss Recoverable [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [3] | 858 | 0
Global Structured Finance [Member] | Corporate Asset Backed [Member] | Unearned Premium Revenue [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Liabilities | [4] | 10 | 14
Global Structured Finance [Member] | Corporate Asset Backed [Member] | Loss And Loss Adjustment Expense Reserves Member [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Liabilities | [5] | 0 | 0
Global Public Finance [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Maximum Exposure to Loss |  | 2,231 | 2,524
Global Public Finance [Member] | Investments [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [1] | 0 | 0
Global Public Finance [Member] | Premiums Receivable [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [2] | 9 | 10
Global Public Finance [Member] | Insurance Loss Recoverable [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Assets | [3] | 0 | 0
Global Public Finance [Member] | Unearned Premium Revenue [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Liabilities | [4] | 12 | 14
Global Public Finance [Member] | Loss And Loss Adjustment Expense Reserves Member [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying Value of VIE Liabilities | [5] | $ 0 | $ 0
[1] | Reported within Investments on MBIA's consolidated balance sheets.
[2] | Reported within Premiums receivable on MBIA's consolidated balance sheets.
[3] | Reported within Insurance loss recoverable on MBIA's consolidated balance sheets.
[4] | Reported within Unearned premium revenue on MBIA's consolidated balance sheets.
[5] | Reported within "Loss and loss adjustment expense reserves" on MBIA's consolidated balance sheets.

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- Definition The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=108788376&loc=d3e5747-111685 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph b -URI http://asc.fasb.org/extlink&oid=108788376&loc=d3e5728-111685 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Carrying amount of the assets in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph a -URI http://asc.fasb.org/extlink&oid=108788376&loc=d3e5728-111685 + Details
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- Definition Carrying amount of the liabilities in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph a -URI http://asc.fasb.org/extlink&oid=108788376&loc=d3e5728-111685 + Details
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