XML 133 R106.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Financial Guaranty Variable Interest Entities and Consolidated Investment Vehicles - Unpaid Principal (Details) (Details) - Variable Interest Entity, Primary Beneficiary - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Financial Guaranty Variable Interest Entities |  |
Variable Interest Entity [Line Items] |  |
FG VIEs’ liabilities with recourse | $ 38 | $ 25
FG VIEs’ liabilities without recourse | 16 | 16
Unpaid principal for FG VIEs’ liabilities with recourse | 193 | 568
Financial Guaranty Variable Interest Entities |  |
Variable Interest Entity [Line Items] |  |
FG VIEs’ assets | 264 | 259
Unpaid principal balance for FG VIEs’ assets that were 90 days or more past due | $ 27 | $ 29

X
- Definition Fair Value, Option, Liabilities with Recourse, Unpaid Principal Balance + References No definition available. + Details
Name: | ago_FairValueOptionLiabilitieswithRecourseUnpaidPrincipalBalance
Namespace Prefix: | ago_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair Value, Option, Loans Held as Liabilities, Aggregate Difference, With Recourse + References No definition available. + Details
Name: | ago_FairValueOptionLoansHeldasLiabilitiesAggregateDifferenceWithRecourse
Namespace Prefix: | ago_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair Value, Option, Loans Held as Liabilities, Aggregate Difference, Without Recourse + References No definition available. + Details
Name: | ago_FairValueOptionLoansHeldasLiabilitiesAggregateDifferenceWithoutRecourse
Namespace Prefix: | ago_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition This item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of loans and long-term receivables (other than securities categorized as trading, available-for-sale or held-to-maturity) that have contractual principal amounts and for which the fair value option has been elected. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (d)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-28 + Details
Name: | us-gaap_FairValueOptionAggregateDifferencesLoansAndLongTermReceivables
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the aggregate fair value of loans held as assets that are 90 days or more past due for which the fair value option has been elected. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (e)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-28 + Details
Name: | us-gaap_FairValueOptionLoansHeldAsAssets90DaysOrMorePastDue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 810 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481203/810-10-50-3 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 810 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 25 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481231/810-10-45-25 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 810 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (bb) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481203/810-10-50-3 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 810 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 25 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481231/810-10-45-25 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (b)(1)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481420/860-30-50-1A Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (b)(1)(ii) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481420/860-30-50-1A Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481420/860-30-50-1A + Details
Name: | us-gaap_VariableInterestEntityLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByLiabilityClassAxis=ago_FinancialGuarantyVariableInterestEntitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=ago_FinancialGuarantyVariableInterestEntitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |