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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 |  |
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Dec. 31, 2022 USD ($) | Dec. 31, 2022 GBP (£) | Dec. 31, 2022 EUR (€) | Dec. 31, 2021 USD ($) | Dec. 31, 2021 GBP (£) | Dec. 31, 2021 EUR (€) | Dec. 31, 2020 USD ($) | Jan. 01, 2020 USD ($) | Dec. 31, 2019 USD ($)
Insurance [Line Items] |  |  |  |  |  |  |  |  |
Premium Receivable, Allowance for Credit Loss | $ 5 |  |  | $ 9 |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Beginning premium receivable | 320 |  |  | 370 |  |  | $ 416 |  |
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest | 1,305 |  |  | 1,098 |  |  | 1,140 |  | $ 1,536
Premium receipts | 36 |  |  | 35 |  |  | (46) |  |
Adjustments for changes in expected and contractual cash flows | (31) |  |  | (27) |  |  | (6) |  |
Accretion of premium receivable discount | 8 |  |  | 8 |  |  | 9 |  |
Uncollectable premiums | 4 |  |  | 8 |  |  | (4) |  |
Other adjustments (including foreign exchange) | (12) |  |  | (4) |  |  | 5 |  |
Ending premium receivable | 254 |  |  | 320 |  |  | 370 |  |
Allowance for Doubtful Accounts, Premiums and Other Receivables | 5 |  |  | 9 |  |  | 17 |  |
Premium Receivable, Credit Loss Expense (Reversal) | (4) |  |  | (6) |  |  |  |  |
Premium Receivable, Allowance for Credit Loss, Writeoff | 0 |  |  | (2) |  |  |  |  |
Premiums Receivable, Gross | 259 |  |  | 329 |  |  |  |  |
Premium Receivable, Allowance for Credit Loss, Recovery | 0 |  |  | 0 |  |  |  |  |
Financial Guarantee Insurance Contracts, Premiums Receivable, Increase (Decrease), Foreign Exchange | (13) |  |  | (2) |  |  | 4 |  |
Past Due Premiums | 0 |  |  | 0 |  |  |  |  |
Specialty Property & Casualty Program [Domain] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 16 |  |  | 2 |  |  |  |  |
Surveillance Category One [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 217 |  |  | 277 |  |  |  |  |
IA [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 10 |  |  | 12 |  |  |  |  |
II [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 5 |  |  | 6 |  |  |  |  |
III [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 16 |  |  | 22 |  |  |  |  |
IV [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 11 |  |  | 12 |  |  |  |  |
Premiums Receivable [Member] | Accounting Standards Update 2016-13 [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest |  |  |  |  |  |  |  | $ (3) |
United Kingdom, Pounds |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Beginning premium receivable | 108 | £ 80 |  | 117 | £ 86 |  |  |  |
Ending premium receivable | 71 | £ 59 |  | 108 | £ 80 |  | 117 |  |
Euro Member Countries, Euro |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Beginning premium receivable | 16 |  | € 14 | 19 |  | € 16 |  |  |
Ending premium receivable | 14 |  | € 13 | 16 |  | € 14 | $ 19 |  |
Structured Finance [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 24 |  |  | 45 |  |  |  |  |
Structured Finance [Member] | Mortgage-backed and Home Equity [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 11 |  |  | 16 |  |  |  |  |
Structured Finance [Member] | Student Loan [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 8 |  |  | 12 |  |  |  |  |
Structured Finance [Member] | Structured Insurance [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 10 |  |  |  |  |
Structured Finance [Member] | Other Structured Finance [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 4 |  |  | 7 |  |  |  |  |
Structured Finance [Member] | Surveillance Category One [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 5 |  |  | 19 |  |  |  |  |
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 |  |  | 1 |  |  |  |  |
Structured Finance [Member] | Surveillance Category One [Member] | Student Loan [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 1 |  |  | 1 |  |  |  |  |
Structured Finance [Member] | Surveillance Category One [Member] | Structured Insurance [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 10 |  |  |  |  |
Structured Finance [Member] | Surveillance Category One [Member] | Other Structured Finance [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 4 |  |  | 7 |  |  |  |  |
Structured Finance [Member] | IA [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 1 |  |  | 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 | 1 |  |  | 1 |  |  |  |  |
Structured Finance [Member] | IA [Member] | Structured Insurance [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |  |
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 |  |  | 1 |  |  |  |  |
Structured Finance [Member] | II [Member] | Mortgage-backed and Home Equity [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 1 |  |  |  |  |
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] | Structured Insurance [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 |  |  | 12 |  |  |  |  |
Structured Finance [Member] | III [Member] | Mortgage-backed and Home Equity [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 2 |  |  |  |  |
Structured Finance [Member] | III [Member] | Student Loan [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 7 |  |  | 9 |  |  |  |  |
Structured Finance [Member] | III [Member] | Structured Insurance [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 0 |  |  | 0 |  |  |  |  |
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 |  |  | 12 |  |  |  |  |
Structured Finance [Member] | IV [Member] | Mortgage-backed and Home Equity [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 11 |  |  | 12 |  |  |  |  |
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] | Structured Insurance [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 | 150 |  |  | 159 |  |  |  |  |
Public Finance [Member] | Housing Revenue [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 148 |  |  | 157 |  |  |  |  |
Public Finance [Member] | Other Public Finance Sectors [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 2 |  |  | 2 |  |  |  |  |
Public Finance [Member] | Surveillance Category One [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 142 |  |  | 151 |  |  |  |  |
Public Finance [Member] | Surveillance Category One [Member] | Housing Revenue [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 140 |  |  | 149 |  |  |  |  |
Public Finance [Member] | Surveillance Category One [Member] | Other Public Finance Sectors [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 2 |  |  | 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 |  |  | 125 |  |  |  |  |
International Finance [Member] | Sovereign/Sub-sovereign [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 64 |  |  | 93 |  |  |  |  |
International Finance [Member] | Investor-owned and Public Utilities [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 18 |  |  | 28 |  |  |  |  |
International Finance [Member] | Other International [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 2 |  |  | 5 |  |  |  |  |
International Finance [Member] | Surveillance Category One [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 70 |  |  | 107 |  |  |  |  |
International Finance [Member] | Surveillance Category One [Member] | Sovereign/Sub-sovereign [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 49 |  |  | 74 |  |  |  |  |
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 |  |  | 28 |  |  |  |  |
International Finance [Member] | Surveillance Category One [Member] | Other International [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 2 |  |  | 5 |  |  |  |  |
International Finance [Member] | IA [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 7 |  |  | 8 |  |  |  |  |
International Finance [Member] | IA [Member] | Sovereign/Sub-sovereign [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 7 |  |  | 8 |  |  |  |  |
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 | 9 |  |  | 11 |  |  |  |  |
International Finance [Member] | III [Member] | Sovereign/Sub-sovereign [Member] |  |  |  |  |  |  |  |  |
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward] |  |  |  |  |  |  |  |  |
Premiums Receivable, Gross | 9 |  |  | 11 |  |  |  |  |
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] |  |  |  |  |  |  |  |  |
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