XML 66 R52.htm IDEA: XBRL DOCUMENT
v3.24.3

Expected Loss to be Paid (Recovered) - Net Expected Loss to be Paid (Recovered) and Net Economic Loss Development (Benefit) by Accounting Model (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2024 | Sep. 30, 2023 | Jun. 30, 2024 | Dec. 31, 2023 | Jun. 30, 2023 | Dec. 31, 2022
Schedule of Expected Losses to be Paid [Line Items] |  |  |  |  |  |  |  |
Net Expected Loss to be Paid (Recovered) | $ 306 | $ 490 | $ 306 | $ 490 | $ 447 | $ 505 | $ 560 | $ 522
Net economic loss development (benefit) | (34) | 87 | (20) | 147 |  |  |  |
Insurance |  |  |  |  |  |  |  |
Schedule of Expected Losses to be Paid [Line Items] |  |  |  |  |  |  |  |
Net Expected Loss to be Paid (Recovered) | 70 |  | 70 |  |  | 263 |  |
Net economic loss development (benefit) | (31) | 92 | (19) | 160 |  |  |  |
FG VIEs' assets |  |  |  |  |  |  |  |
Schedule of Expected Losses to be Paid [Line Items] |  |  |  |  |  |  |  |
Net Expected Loss to be Paid (Recovered) | 236 |  | 236 |  |  | 240 |  |
Net economic loss development (benefit) | (1) | (6) | 0 | (15) |  |  |  |
Credit derivatives |  |  |  |  |  |  |  |
Schedule of Expected Losses to be Paid [Line Items] |  |  |  |  |  |  |  |
Net Expected Loss to be Paid (Recovered) | 0 |  | 0 |  |  | $ 2 |  |
Net economic loss development (benefit) | $ (2) | $ 1 | $ (1) | $ 2 |  |  |  |

X
- Definition Guarantor Obligations, Net Expected Loss Development After Recoveries for Representations and Warranties + References No definition available. + Details
Name: | ago_GuarantorObligationsNetExpectedLossDevelopmentAfterRecoveriesforRepresentationsandWarranties
Namespace Prefix: | ago_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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] for Schedule of Expected Losses to be Paid [Table] + References No definition available. + Details
Name: | ago_ScheduleofExpectedLossestobePaidLineItems
Namespace Prefix: | ago_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=ago_InsuranceContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=ago_FinancialGuaranteeVariableInterestEntitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=ago_FinancialGuaranteeAccountedforasCreditDerivativesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |