XML 77 R63.htm IDEA: XBRL DOCUMENT
v3.24.3

Contracts Accounted for as Insurance - Reconciliation of Net Expected Loss to be Paid and Expensed (Details) - USD ($) $ in Millions | Sep. 30, 2024 | Jun. 30, 2024 | Dec. 31, 2023 | Sep. 30, 2023 | Jun. 30, 2023 | Dec. 31, 2022
--- | --- | --- | --- | --- | --- | ---
Guarantor Obligations [Line Items] |  |  |  |  |  |
Net expected loss to be paid (recovered) - financial guaranty insurance | $ 306 | $ 447 | $ 505 | $ 490 | $ 560 | $ 522
Net expected loss to be expensed (present value) | 252 |  |  |  |  |
Financial Guarantee Insurance And Other Product Line |  |  |  |  |  |
Guarantor Obligations [Line Items] |  |  |  |  |  |
Net expected loss to be paid (recovered) - financial guaranty insurance | 69 |  |  |  |  |
Contra-paid, net | 24 |  |  |  |  |
Salvage and subrogation recoverable, net | 410 |  |  |  |  |
Loss and LAE reserve - financial guaranty insurance contracts, net of reinsurance | (251) |  |  |  |  |
Net expected loss to be expensed (present value) | $ 252 |  |  |  |  |

X
- Definition Financial Guarantee Insurance Contracts, Net Loss to be Expensed, Present Value + References No definition available. + Details
Name: | ago_FinancialGuaranteeInsuranceContractsNetLosstobeExpensedPresentValue
Namespace Prefix: | ago_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of losses paid and not yet expensed on financial guaranty insurance contracts, net of ceded amounts. + References No definition available. + Details
Name: | ago_FinancialGuaranteeInsuranceContractsPaidButUnexpensedLossesNet
Namespace Prefix: | ago_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financial Guarantee Insurance Contracts, Salvage and Subrogation Recoveries, Net + References No definition available. + Details
Name: | ago_FinancialGuaranteeInsuranceContractsSalvageandSubrogationRecoveriesNet
Namespace Prefix: | ago_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Guarantor Obligations, Net Expected Loss to be Paid After Recoveries for Representations and Warranties + References No definition available. + Details
Name: | ago_GuarantorObligationsNetExpectedLosstobePaidAfterRecoveriesforRepresentationsandWarranties
Namespace Prefix: | ago_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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 460 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482425/460-10-50-4 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 460 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482425/460-10-50-4 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 460 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482425/460-10-50-4 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 460 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482425/460-10-50-4 + Details
Name: | us-gaap_GuaranteeObligationsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Liability as of the balance sheet date for amounts representing estimated cost of settling unpaid claims under the terms of the underlying insurance policies, less estimated reinsurance recoveries on such claims. This includes an estimate for claims which have been incurred but not reported. Claim adjustment expenses represent the costs estimated to be incurred in the settlement of unpaid claims. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(13)(a)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (cc) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-3 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480081/944-40-50-3 + Details
Name: | us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | srt_ProductOrServiceAxis=ago_FinancialGuaranteeInsuranceAndOtherProductLineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |