XML 55 R42.htm IDEA: XBRL DOCUMENT
v3.24.2.u1

Outstanding Exposure - Financial Guaranty Portfolio by Internal Rating (Details) - USD ($) $ in Millions | Jun. 30, 2024 | Dec. 31, 2023
--- | --- | ---
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 254,396 | $ 249,153
% of total net par outstanding | 100.00% | 100.00%
AAA |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 3,220 | $ 3,504
% of total net par outstanding | 1.20% | 1.40%
AA |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 26,961 | $ 25,868
% of total net par outstanding | 10.60% | 10.40%
A |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 121,607 | $ 118,123
% of total net par outstanding | 47.80% | 47.40%
BBB |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 97,106 | $ 96,221
% of total net par outstanding | 38.20% | 38.60%
BIG |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 5,502 | $ 5,437
% of total net par outstanding | 2.20% | 2.20%
Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 244,176 | $ 239,296
Public finance | United States |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 194,593 | $ 190,289
% of total net par outstanding | 100.00% | 100.00%
Public finance | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 49,583 | $ 49,007
% of total net par outstanding | 100.00% | 100.00%
Public finance | AAA | United States |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 27 | $ 110
% of total net par outstanding | 0.00% | 0.10%
Public finance | AAA | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 2,066 | $ 2,062
% of total net par outstanding | 4.20% | 4.20%
Public finance | AA | United States |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 18,100 | $ 17,883
% of total net par outstanding | 9.30% | 9.40%
Public finance | AA | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 3,164 | $ 3,379
% of total net par outstanding | 6.30% | 6.90%
Public finance | A | United States |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 106,415 | $ 102,945
% of total net par outstanding | 54.70% | 54.10%
Public finance | A | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 13,437 | $ 12,968
% of total net par outstanding | 27.10% | 26.50%
Public finance | BBB | United States |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 66,561 | $ 66,080
% of total net par outstanding | 34.20% | 34.70%
Public finance | BBB | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 29,831 | $ 29,467
% of total net par outstanding | 60.20% | 60.10%
Public finance | BIG |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 4,575 | $ 4,402
Public finance | BIG | United States |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 3,490 | $ 3,271
% of total net par outstanding | 1.80% | 1.70%
Public finance | BIG | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 1,085 | $ 1,131
% of total net par outstanding | 2.20% | 2.30%
Structured finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 10,220 | $ 9,857
Structured finance | United States |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 8,759 | $ 8,632
% of total net par outstanding | 100.00% | 100.00%
Structured finance | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 1,461 | $ 1,225
% of total net par outstanding | 100.00% | 100.00%
Structured finance | AAA | United States |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 682 | $ 867
% of total net par outstanding | 7.80% | 10.00%
Structured finance | AAA | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 445 | $ 465
% of total net par outstanding | 30.50% | 38.00%
Structured finance | AA | United States |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 5,623 | $ 4,517
% of total net par outstanding | 64.20% | 52.30%
Structured finance | AA | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 74 | $ 89
% of total net par outstanding | 5.00% | 7.30%
Structured finance | A | United States |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 902 | $ 1,639
% of total net par outstanding | 10.30% | 19.00%
Structured finance | A | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 853 | $ 571
% of total net par outstanding | 58.40% | 46.60%
Structured finance | BBB | United States |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 625 | $ 574
% of total net par outstanding | 7.10% | 6.70%
Structured finance | BBB | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 89 | $ 100
% of total net par outstanding | 6.10% | 8.10%
Structured finance | BIG |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 927 | $ 1,035
Structured finance | BIG | United States |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 927 | $ 1,035
% of total net par outstanding | 10.60% | 12.00%
Structured finance | BIG | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 0 | $ 0
% of total net par outstanding | 0.00% | 0.00%

X
- Definition Represents the outstanding principal amounts of the underlying insured obligations for financial guaranty contracts, after netting out ceded contracts. + References No definition available. + Details
Name: | ago_InsuredFinancialObligationsOutstandingPrincipalAmountNet
Namespace Prefix: | ago_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Represents the net outstanding principal amounts of the underlying insured obligations for each category of financial guaranty contracts, as a percentage of the total outstanding principal amount within the identified asset class. + References No definition available. + Details
Name: | ago_InsuredFinancialObligationsOutstandingPrincipleAmountPercentage
Namespace Prefix: | ago_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition [Line Items] for Schedule of Insured Financial Obligations [Table] + References No definition available. + Details
Name: | ago_ScheduleofInsuredFinancialObligationsLineItems
Namespace Prefix: | ago_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=ago_InternalInvestmentGradeAAAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=ago_InternalInvestmentGradeAAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=ago_InternalInvestmentGradeAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=ago_InternalInvestmentGradeBBBMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_InternalNoninvestmentGradeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_UnderlyingAssetClassAxis=ago_PublicFinanceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_US
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=us-gaap_NonUsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_UnderlyingAssetClassAxis=us-gaap_StructuredFinanceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |