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Insurance in Force (Narrative) (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Guarantor Obligations [Line Items] |  |  |  |
Transactions guaranteed by MBIA on behalf of affiliated companies |  | $ 2,000 |  |
Aggregate amount of insurance in force ceded to reinsurers |  | 4,200 | $ 5,100 |
Aggregate amount of insured par outstanding ceded to reinsurers |  | 2,194 | 2,700 |
Ceding commissions from reinsurance | [1] | 317 | 370 | $ 480
Insurance in Force |  | 128,100 | 154,900 |
Gross Par Amount |  | 69,800 | $ 87,000 |
U S Public Finance Insurance [Member] |  |  |  |
Guarantor Obligations [Line Items] |  |  |  |
Aggregate amount of insured par outstanding ceded to reinsurers |  | 1,700 |  |
Structured Finance And International Insurance [Member] |  |  |  |
Guarantor Obligations [Line Items] |  |  |  |
Aggregate amount of insured par outstanding ceded to reinsurers |  | $ 499 |  |
Financial Guaranty Insurance Company [Member] |  |  |  |
Guarantor Obligations [Line Items] |  |  |  |
Financial guaranty maturity year |  | 2058 |  |
Investment agreements, MTNs and other affiliated contracts [Member] |  |  |  |
Guarantor Obligations [Line Items] |  |  |  |
Financial guaranty maturity year |  | 2037 |  |
[1] | Represents the sum of third-party financial guarantee net premiums earned, net investment income, insurance-related fees and reimbursements and other fees.

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- Definition Aggregate Amount Of Insurance In Force Outstanding Ceded To Reinsurers + References No definition available. + Details
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- Definition Aggregate amount of insured par outstanding ceded to reinsurers. + References No definition available. + Details
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- Definition Represents the amount of insured contractual payments (principal and interest) outstanding on the underlying insured obligations for financial guaranty contracts, gross of ceded contracts. + References No definition available. + Details
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- Definition Represents the outstanding principal amounts of the underlying insured obligations for financial guaranty contracts, gross of ceded contracts. + References No definition available. + Details
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- Definition Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130539-203045 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130545-203045 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130543-203045 + Details
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