XML 63 R43.htm IDEA: XBRL DOCUMENT
v3.22.1

Outstanding Exposure - Financial Guaranty Portfolio by Internal Rating (Details) - USD ($) $ in Millions | Mar. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 233,379 | $ 236,392
% of total net par outstanding | 100.00% | 100.00%
AAA |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 3,611 | $ 3,788
% of total net par outstanding | 1.50% | 1.60%
AA |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 25,101 | $ 25,359
% of total net par outstanding | 10.80% | 10.70%
A |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 105,781 | $ 106,091
% of total net par outstanding | 45.30% | 44.90%
BBB |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 93,247 | $ 93,798
% of total net par outstanding | 40.00% | 39.70%
BIG |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 5,639 | $ 7,356
% of total net par outstanding | 2.40% | 3.10%
Public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 224,463 | $ 227,164
Public finance | UNITED STATES |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 175,957 | $ 177,219
% of total net par outstanding | 100.00% | 100.00%
Public finance | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 48,506 | $ 49,945
% of total net par outstanding | 100.00% | 100.00%
Public finance | AAA | UNITED STATES |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 270 | $ 272
% of total net par outstanding | 0.20% | 0.20%
Public finance | AAA | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 2,102 | $ 2,217
% of total net par outstanding | 4.30% | 4.50%
Public finance | AA | UNITED STATES |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 16,472 | $ 16,372
% of total net par outstanding | 9.40% | 9.20%
Public finance | AA | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 3,975 | $ 4,205
% of total net par outstanding | 8.20% | 8.40%
Public finance | A | UNITED STATES |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 94,442 | $ 94,459
% of total net par outstanding | 53.60% | 53.30%
Public finance | A | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 10,382 | $ 10,659
% of total net par outstanding | 21.40% | 21.30%
Public finance | BBB | UNITED STATES |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 61,039 | $ 60,744
% of total net par outstanding | 34.70% | 34.30%
Public finance | BBB | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 31,486 | $ 32,264
% of total net par outstanding | 64.90% | 64.60%
Public finance | BIG |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 4,295 | $ 5,972
Public finance | BIG | UNITED STATES |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 3,734 | $ 5,372
% of total net par outstanding | 2.10% | 3.00%
Public finance | BIG | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 561 | $ 600
% of total net par outstanding | 1.20% | 1.20%
Structured finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 8,916 | $ 9,228
Structured finance | UNITED STATES |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 8,101 | $ 8,374
% of total net par outstanding | 100.00% | 100.00%
Structured finance | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 815 | $ 854
% of total net par outstanding | 100.00% | 100.00%
Structured finance | AAA | UNITED STATES |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 757 | $ 806
% of total net par outstanding | 9.30% | 9.60%
Structured finance | AAA | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 482 | $ 493
% of total net par outstanding | 59.10% | 57.70%
Structured finance | AA | UNITED STATES |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 4,633 | $ 4,760
% of total net par outstanding | 57.20% | 56.80%
Structured finance | AA | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 21 | $ 22
% of total net par outstanding | 2.70% | 2.60%
Structured finance | A | UNITED STATES |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 801 | $ 813
% of total net par outstanding | 9.90% | 9.70%
Structured finance | A | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 156 | $ 160
% of total net par outstanding | 19.10% | 18.70%
Structured finance | BBB | UNITED STATES |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 566 | $ 611
% of total net par outstanding | 7.00% | 7.30%
Structured finance | BBB | Non-U.S. public finance |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 156 | $ 179
% of total net par outstanding | 19.10% | 21.00%
Structured finance | BIG |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 1,344 | $ 1,384
Structured finance | BIG | UNITED STATES |  |
Schedule of Insured Financial Obligations [Line Items] |  |
Net | $ 1,344 | $ 1,384
% of total net par outstanding | 16.60% | 16.60%
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-types: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: |