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Variable Interest Entities (Summary Of Nonconsolidated VIEs Assets And Liabilities) (Detail) - USD ($) $ in Millions | Jun. 30, 2018 | Dec. 31, 2017
--- | --- | ---
Global Structured Finance [Member] |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |
VIE Assets |  | $ 15,022 |  | $ 14,939
Maximum Exposure to Loss |  | 5,708 |  | 6,461
Investments | [1] | 19 |  | 19
Premiums receivable | [2] | 33 |  | 39
Insurance loss recoverable | [3] | 989 |  | 173
Unearned premium revenue | [4] | 33 |  | 37
Loss and loss adjustment expense reserves | [5] | 371 |  | 406
Global Structured Finance [Member] | Residential Mortgage Backed Securities [Member] |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |
VIE Assets |  | 6,187 |  | 7,295
Maximum Exposure to Loss |  | 3,396 |  | 3,741
Investments | [1] | 19 |  | 19
Premiums receivable | [2] | 20 |  | 22
Insurance loss recoverable | [3] | 149 |  | 172
Unearned premium revenue | [4] | 19 |  | 20
Loss and loss adjustment expense reserves | [5] | 361 |  | 396
Global Structured Finance [Member] | Commercial Mortgage Backed Securities [Member] |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |
VIE Assets |  | 139 |  | 216
Maximum Exposure to Loss |  | 67 |  | 94
Premiums receivable |  | 0 | [2] | 0
Unearned premium revenue |  | 0 | [4] | 0
Global Structured Finance [Member] | Consumer Asset Backed [Member] |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |
VIE Assets |  | 4,787 |  | 5,010
Maximum Exposure to Loss |  | 798 |  | 981
Premiums receivable | [2] | 3 |  | 4
Insurance loss recoverable | [3] | 1 |  | 1
Unearned premium revenue | [4] | 3 |  | 3
Loss and loss adjustment expense reserves | [5] | 10 |  | 10
Global Structured Finance [Member] | Corporate Asset Backed [Member] |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |
VIE Assets |  | 3,909 |  | 2,418
Maximum Exposure to Loss |  | 1,447 |  | 1,645
Investments | [1] | 0 |  | 0
Premiums receivable | [2] | 10 |  | 13
Insurance loss recoverable |  | 839 | [3] | 0
Unearned premium revenue | [4] | 11 |  | 14
Global Public Finance [Member] |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |
VIE Assets |  | 15,317 |  | 15,568
Maximum Exposure to Loss |  | 2,352 |  | 2,524
Premiums receivable | [2] | 10 |  | 10
Unearned premium revenue | [4] | 12 |  | 14
Total Insurance [Member] |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |
VIE Assets |  | 30,339 |  | 30,507
Maximum Exposure to Loss |  | 8,060 |  | 8,985
Investments | [1] | 19 |  | 19
Premiums receivable | [2] | 43 |  | 49
Insurance loss recoverable | [3] | 989 |  | 173
Unearned premium revenue | [4] | 45 |  | 51
Loss and loss adjustment expense reserves | [5] | $ 371 |  | $ 406
[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 Sum of the carrying amounts as of the balance sheet date of all investments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.1(h)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
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