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Financial Guarantee Insurance Contracts - Summary of Gross Premium Receivable Roll-Forward (Direct and Assumed Contracts) (Detail) € in Millions, £ in Millions, $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2023 USD ($) | Dec. 31, 2023 GBP (£) | Dec. 31, 2023 EUR (€) | Dec. 31, 2022 USD ($) | Dec. 31, 2022 GBP (£) | Dec. 31, 2022 EUR (€) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($)
Insurance [Line Items] |  |  |  |  |  |  |  |
Premium Receivable, Allowance for Credit Loss | $ 4 |  |  | $ 5 |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest | 1,415 |  |  | 1,305 |  |  | $ 1,098 | $ 1,140
Premiums Written, Net | 210 |  |  | 117 |  |  | 10 |
Proceeds from Insurance Premiums Collected | (208) |  |  | (139) |  |  | (43) |
Adjustments for changes in expected and contractual cash flows | 6 |  |  | (31) |  |  | (27) |
Accretion of premium receivable discount | 8 |  |  | 8 |  |  | 8 |
Financial Guarantee Insurance Contracts, Consolidation of VIE | (1) |  |  |  |  |  |  |
Other adjustments (including foreign exchange) | 4 |  |  | (12) |  |  | (4) |
Allowance for Doubtful Accounts, Premiums and Other Receivables | 4 |  |  | 5 |  |  | 9 | 17
Premium Receivable, Credit Loss Expense (Reversal) | (1) |  |  | (4) |  |  | (6) |
Premium Receivable, Allowance for Credit Loss, Writeoff | 0 |  |  | 0 |  |  | (2) |
Premiums Receivable, Gross | 290 |  |  | 269 |  |  | 323 | $ 370
Premium Receivable, Allowance for Credit Loss, Recovery | 0 |  |  | 0 |  |  | 0 |
Past Due Premiums | 1 |  |  | 0 |  |  |  |
Premium Receivable, Allowance for Credit Loss, Period Increase (Decrease) | 1 |  |  | 4 |  |  | 8 |
Foreign Exchange | Real Estate [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Other adjustments (including foreign exchange) | 4 |  |  | (13) |  |  | (2) |
Specialty Property & Casualty Program [Domain] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 46 |  |  | 16 |  |  |  |
Legacy Financial Guarantee |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 248 |  |  | 259 |  |  |  |
Surveillance Category One [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 210 |  |  | 217 |  |  |  |
IA [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 16 |  |  | 10 |  |  |  |
II [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 5 |  |  | 5 |  |  |  |
III [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 7 |  |  | 16 |  |  |  |
IV [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 11 |  |  | 11 |  |  |  |
United Kingdom, Pounds |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Beginning premium receivable | 71 | £ 59 |  | 108 | £ 80 |  |  |
Ending premium receivable | 72 | £ 57 |  | 71 | £ 59 |  | 108 |
Euro Member Countries, Euro |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Beginning premium receivable | 14 |  | € 13 | 16 |  | € 14 |  |
Ending premium receivable | 13 |  | € 12 | 14 |  | € 13 | $ 16 |
Structured Finance [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 22 |  |  | 24 |  |  |  |
Structured Finance [Member] | Mortgage-backed and Home Equity [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 12 |  |  | 11 |  |  |  |
Structured Finance [Member] | Student Loan [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 7 |  |  | 8 |  |  |  |
Structured Finance [Member] | Other Structured Finance [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 4 |  |  | 4 |  |  |  |
Structured Finance [Member] | Surveillance Category One [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 4 |  |  | 5 |  |  |  |
Structured Finance [Member] | Surveillance Category One [Member] | Mortgage-backed and Home Equity [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Structured Finance [Member] | Surveillance Category One [Member] | Student Loan [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 1 |  |  |  |
Structured Finance [Member] | Surveillance Category One [Member] | Other Structured Finance [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 4 |  |  | 4 |  |  |  |
Structured Finance [Member] | IA [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 1 |  |  |  |
Structured Finance [Member] | IA [Member] | Mortgage-backed and Home Equity [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Structured Finance [Member] | IA [Member] | Student Loan [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 1 |  |  |  |
Structured Finance [Member] | IA [Member] | Other Structured Finance [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Structured Finance [Member] | II [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Structured Finance [Member] | II [Member] | Mortgage-backed and Home Equity [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Structured Finance [Member] | II [Member] | Student Loan [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Structured Finance [Member] | II [Member] | Other Structured Finance [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Structured Finance [Member] | III [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 7 |  |  | 7 |  |  |  |
Structured Finance [Member] | III [Member] | Mortgage-backed and Home Equity [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Structured Finance [Member] | III [Member] | Student Loan [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 7 |  |  | 7 |  |  |  |
Structured Finance [Member] | III [Member] | Other Structured Finance [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Structured Finance [Member] | IV [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 11 |  |  | 11 |  |  |  |
Structured Finance [Member] | IV [Member] | Mortgage-backed and Home Equity [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 11 |  |  | 11 |  |  |  |
Structured Finance [Member] | IV [Member] | Student Loan [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Structured Finance [Member] | IV [Member] | Other Structured Finance [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Public Finance [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 140 |  |  | 150 |  |  |  |
Public Finance [Member] | Housing Revenue [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 139 |  |  | 148 |  |  |  |
Public Finance [Member] | Other Public Finance Sectors [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 1 |  |  | 2 |  |  |  |
Public Finance [Member] | Surveillance Category One [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 133 |  |  | 142 |  |  |  |
Public Finance [Member] | Surveillance Category One [Member] | Housing Revenue [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 131 |  |  | 140 |  |  |  |
Public Finance [Member] | Surveillance Category One [Member] | Other Public Finance Sectors [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 1 |  |  | 2 |  |  |  |
Public Finance [Member] | IA [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 3 |  |  | 3 |  |  |  |
Public Finance [Member] | IA [Member] | Housing Revenue [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 3 |  |  | 3 |  |  |  |
Public Finance [Member] | IA [Member] | Other Public Finance Sectors [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Public Finance [Member] | II [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 5 |  |  | 5 |  |  |  |
Public Finance [Member] | II [Member] | Housing Revenue [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 5 |  |  | 5 |  |  |  |
Public Finance [Member] | II [Member] | Other Public Finance Sectors [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Public Finance [Member] | III [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Public Finance [Member] | III [Member] | Housing Revenue [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Public Finance [Member] | III [Member] | Other Public Finance Sectors [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Public Finance [Member] | IV [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Public Finance [Member] | IV [Member] | Housing Revenue [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
Public Finance [Member] | IV [Member] | Other Public Finance Sectors [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
International Finance [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 85 |  |  | 85 |  |  |  |
International Finance [Member] | Sovereign/Sub-sovereign [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 64 |  |  | 64 |  |  |  |
International Finance [Member] | Investor-owned and Public Utilities [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 18 |  |  | 18 |  |  |  |
International Finance [Member] | Other International [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 3 |  |  | 2 |  |  |  |
International Finance [Member] | Surveillance Category One [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 72 |  |  | 70 |  |  |  |
International Finance [Member] | Surveillance Category One [Member] | Sovereign/Sub-sovereign [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 51 |  |  | 49 |  |  |  |
International Finance [Member] | Surveillance Category One [Member] | Investor-owned and Public Utilities [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 18 |  |  | 18 |  |  |  |
International Finance [Member] | Surveillance Category One [Member] | Other International [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 3 |  |  | 2 |  |  |  |
International Finance [Member] | IA [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 13 |  |  | 7 |  |  |  |
International Finance [Member] | IA [Member] | Sovereign/Sub-sovereign [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 13 |  |  | 7 |  |  |  |
International Finance [Member] | IA [Member] | Investor-owned and Public Utilities [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
International Finance [Member] | IA [Member] | Other International [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
International Finance [Member] | II [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
International Finance [Member] | II [Member] | Sovereign/Sub-sovereign [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
International Finance [Member] | II [Member] | Investor-owned and Public Utilities [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
International Finance [Member] | II [Member] | Other International [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
International Finance [Member] | III [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 9 |  |  |  |
International Finance [Member] | III [Member] | Sovereign/Sub-sovereign [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 9 |  |  |  |
International Finance [Member] | III [Member] | Investor-owned and Public Utilities [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
International Finance [Member] | III [Member] | Other International [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
International Finance [Member] | IV [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
International Finance [Member] | IV [Member] | Sovereign/Sub-sovereign [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
International Finance [Member] | IV [Member] | Investor-owned and Public Utilities [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |
International Finance [Member] | IV [Member] | Other International [Member] |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |
Premiums Receivable, Gross | $ 0 |  |  | $ 0 |  |  |  |

X
- Definition Financial Guarantee Insurance Contracts, Consolidation of VIE + References No definition available. + Details
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Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Insurance [Line Items] + References No definition available. + Details
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Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Past Due Premiums + References No definition available. + Details
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Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The valuation allowance as of the balance sheet date to reduce the gross amount of receivables to estimated net realizable value, which would be presented in parentheses on the face of the balance sheet. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-4 + Details
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Namespace Prefix: | us-gaap_
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Balance Type: | credit
Period Type: | instant

X
- Definition Amount of the premium receivable for financial guarantee insurance contracts reported in the statement of financial position. This element primarily would consist of those financial guarantee insurance contracts which premiums are to be collected over the contract period, but may, on occasion, include premiums which are to be collected in full at inception, but which straddle a financial reporting period. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 310 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479584/944-310-50-3 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 310 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c)(5) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479584/944-310-50-3 + Details
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