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Loss and Loss Adjustment Expense Reserves (Schedule Of Financial Guarantees And Related Claim Liability) (Detail) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2025 USD ($) Issue Policy | Dec. 31, 2024 USD ($) Issue Policy
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |
Number of policies | Policy |  | 120 | 119
Number of issues | Issue | [1] | 87 | 86
Remaining weighted average contract period (in years) |  | 5 years 9 months 18 days | 6 years 2 months 12 days
Principal | [2] | $ 2,297 | $ 2,226
Interest | [2] | 1,808 | 1,876
Total | [2] | 4,105 | 4,102
Gross claim liability | [3] | 881 | 906
Less: Gross potential recoveries | [4] | 460 | 467
Discount, net | [5] | 101 | 107
Net claim liability (recoverable) |  | 320 | 332
Unearned premium revenue |  | 13 | 13
Reinsurance recoverable on paid and unpaid losses | [6] | $ 16 | $ 16
Caution List Low [Member] |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |
Number of policies | Policy |  | 29 | 29
Number of issues | Issue | [1] | 10 | 10
Remaining weighted average contract period (in years) |  | 5 years 7 months 6 days | 5 years 8 months 12 days
Principal | [2] | $ 699 | $ 717
Interest | [2] | 1,267 | 1,307
Total | [2] | 1,966 | 2,024
Gross claim liability | [3] | 0 | 0
Less: Gross potential recoveries | [4] | 0 | 0
Discount, net | [5] | 0 | 0
Net claim liability (recoverable) |  | 0 | 0
Unearned premium revenue |  | $ 4 | $ 4
Caution List Medium [Member] |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |
Number of policies | Policy |  | 0 | 0
Number of issues | Issue | [1] | 0 | 0
Principal | [2] | $ 0 | $ 0
Interest | [2] | 0 | 0
Total | [2] | 0 | 0
Gross claim liability | [3] | 0 | 0
Less: Gross potential recoveries | [4] | 0 | 0
Discount, net | [5] | 0 | 0
Net claim liability (recoverable) |  | 0 | 0
Unearned premium revenue |  | $ 0 | $ 0
Caution List High [Member] |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |
Number of policies | Policy |  | 0 | 0
Number of issues | Issue | [1] | 0 | 0
Principal | [2] | $ 0 | $ 0
Interest | [2] | 0 | 0
Total | [2] | 0 | 0
Gross claim liability | [3] | 0 | 0
Less: Gross potential recoveries | [4] | 0 | 0
Discount, net | [5] | 0 | 0
Net claim liability (recoverable) |  | 0 | 0
Unearned premium revenue |  | $ 0 | $ 0
Classified List [Member] |  |  |
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |
Number of policies | Policy |  | 91 | 90
Number of issues | Issue | [1] | 77 | 76
Remaining weighted average contract period (in years) |  | 5 years 10 months 24 days | 6 years 4 months 24 days
Principal | [2] | $ 1,598 | $ 1,509
Interest | [2] | 541 | 569
Total | [2] | 2,139 | 2,078
Gross claim liability | [3] | 881 | 906
Less: Gross potential recoveries | [4] | 460 | 467
Discount, net | [5] | 101 | 107
Net claim liability (recoverable) |  | 320 | 332
Unearned premium revenue |  | $ 9 | $ 9
[1] | An “issue” represents the aggregate of financial guarantee policies that share the same revenue source for purposes of making debt service payments on the insured debt.
[2] | Represents contractual principal and interest payments due by the issuer of the obligations insured by MBIA.
[3] | The gross claim liability with respect to Puerto Rico exposures are net of expected recoveries for policies in a net payable position.
[4] | Gross potential recoveries with respect to certain Puerto Rico exposures are net of the claim liability for policies in a net recoverable position.
[5] | Represents discount related to Gross Claim Liability and Gross Potential Recoveries.
[6] | Included in "Other assets" on the Company's consolidated balance sheets.

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- Definition Number Of Policies + References No definition available. + Details
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- Definition Schedule of insured financial obligations with credit deterioration net claim liability recoverable. + References No definition available. + Details
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- Definition Schedule of insured financial obligations with credit deterioration reductions of gross claim liability discount, net. + References No definition available. + Details
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- Definition Remaining weighted average contract period of financial guarantee insurance contracts, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 34 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480046/944-40-55-34 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a)(5)(ii) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-9 + Details
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- Definition Amount, after valuation allowance, recoverable under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, policy benefits and policy reserves. Excludes premiums paid under reinsurance contracts. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 310 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477363/944-310-50-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479838/944-20-50-5 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 310 -Name Accounting Standards Codification -Section 45 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477409/944-310-45-5 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 310 -Name Accounting Standards Codification -Section 45 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477409/944-310-45-6 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 825 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477351/944-825-50-1B + Details
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- Definition This element represents the gross claim liability for financial guarantee insurance contracts presented in the context of each surveillance grouping or category used by management to monitor and track potential deterioration in the credit worthiness of the insured party's ability to meet its financial obligations related to the contracts underlying financial guarantee insurance contracts the entity has issued. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 34 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480046/944-40-55-34 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a)(5)(iv) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-9 + Details
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- Definition This element represents the amount of insured contractual payments outstanding on the underlying insured obligations for financial guarantee insurance contracts presented in the context of each surveillance grouping or category used by management to monitor and track potential deterioration in the credit worthiness of the insured party's ability to meet its financial obligations related to the contracts underlying financial guarantee insurance contracts the entity has issued. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 34 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480046/944-40-55-34 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a)(5)(iii) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-9 + Details
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- Definition This element represents the amount of insured contractual payments outstanding attributable to interest accrued on the underlying insured obligations for financial guarantee insurance contracts presented in the context of each surveillance grouping or category used by management to monitor and track potential deterioration in the credit worthiness of the insured party's ability to meet its financial obligations related to the contracts underlying financial guarantee insurance contracts the entity has issued. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 34 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480046/944-40-55-34 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a)(5)(iii) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-9 + Details
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- Definition This element represents the amount of insured contractual payments outstanding attributable to the principal of the underlying insured obligations for financial guarantee insurance contracts presented in the context of each surveillance grouping or category used by management to monitor and track potential deterioration in the credit worthiness of the insured party's ability to meet its financial obligations related to the contracts underlying financial guarantee insurance contracts the entity has issued. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 34 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480046/944-40-55-34 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a)(5)(iii) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-9 + Details
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- Definition This element represents the number of issued and outstanding contracts for each surveillance grouping or category used by management to monitor and track potential deterioration in the credit worthiness of the insured party's ability to meet its financial obligations related to the contracts underlying financial guarantee insurance contracts the entity has issued. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 34 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480046/944-40-55-34 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a)(5)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-9 + Details
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- Definition This element represents the gross potential recoveries against the gross claim liability for financial guarantee insurance contracts presented in the context of each surveillance grouping or category used by management to monitor and track potential deterioration in the credit worthiness of the insured party's ability to meet its financial obligations related to the contracts underlying financial guarantee insurance contracts the entity has issued. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 34 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480046/944-40-55-34 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a)(5)(v) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-9 + Details
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- Definition This element represents the amount of unearned premium revenue, reported on or included in the statement of financial position, related to financial guarantee insurance contracts and presented in the schedule of insured financial obligations with credit deterioration in the context of each surveillance grouping or category used by management to monitor and track potential deterioration in the credit worthiness of the insured party's ability to meet its financial obligations related to the contracts underlying financial guarantee insurance contracts the entity has issued. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 55 -Paragraph 34 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480046/944-40-55-34 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a)(5)(ix) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-9 + Details
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