XML 52 R41.htm IDEA: XBRL DOCUMENT
v3.23.2

Business and Basis of Presentation - Assets and Liabilities Held for Sale (Details) - USD ($) $ in Millions | Jun. 30, 2023 | Dec. 31, 2022 | Jun. 30, 2022
--- | --- | --- | ---
Long-Lived Assets Held-for-sale [Line Items] |  |  |
Cash | $ 20 |  | $ 0
Assets held for sale | 221 | $ 0 |
Liabilities held for sale | 50 | $ 0 |
Disposal Group, Held-for-sale, Not Discontinued Operations | Sound Point Agreement |  |  |
Long-Lived Assets Held-for-sale [Line Items] |  |  |
Short-term investments | 1 |  |
Cash | 20 |  |
Goodwill and other intangible assets | 156 |  |
Deferred tax assets | 3 |  |
Other | 41 |  |
Assets held for sale | 221 |  |
Other liabilities | 50 |  |
Liabilities held for sale | $ 50 |  |

X
- Definition Disposal Group, Including Discontinued Operation, Intangible Assets, Net (Including Goodwill) + References No definition available. + Details
Name: | ago_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsNetIncludingGoodwill
Namespace Prefix: | ago_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Disposal Group, Including Discontinued Operation, Short Term Investments + References No definition available. + Details
Name: | ago_DisposalGroupIncludingDiscontinuedOperationShortTermInvestments
Namespace Prefix: | ago_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount classified as assets attributable to disposal group held for sale or disposed of. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 10 -SubTopic 20 -Topic 205 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483475/205-20-45-10 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483499/205-20-50-7 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5C -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483499/205-20-50-5C Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5B -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483499/205-20-50-5B Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 360 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482099/360-10-50-3 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483475/205-20-45-11 + Details
Name: | us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount classified as cash and cash equivalents attributable to disposal group held for sale or disposed of. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 10 -SubTopic 20 -Topic 205 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483475/205-20-45-10 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5B -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483499/205-20-50-5B Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 360 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482099/360-10-50-3 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483475/205-20-45-11 + Details
Name: | us-gaap_DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount classified as deferred tax assets attributable to disposal group held for sale or disposed of. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 10 -SubTopic 20 -Topic 205 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483475/205-20-45-10 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5B -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483499/205-20-50-5B Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 360 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482099/360-10-50-3 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483475/205-20-45-11 + Details
Name: | us-gaap_DisposalGroupIncludingDiscontinuedOperationDeferredTaxAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount classified as other assets attributable to disposal group held for sale or disposed of. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 10 -SubTopic 20 -Topic 205 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483475/205-20-45-10 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5B -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483499/205-20-50-5B Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 360 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482099/360-10-50-3 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483475/205-20-45-11 + Details
Name: | us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount classified as other liabilities attributable to disposal group held for sale or disposed of. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 10 -SubTopic 20 -Topic 205 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483475/205-20-45-10 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5B -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483499/205-20-50-5B Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 360 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482099/360-10-50-3 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483475/205-20-45-11 + Details
Name: | us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount classified as liabilities attributable to disposal group held for sale or disposed of. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 10 -SubTopic 20 -Topic 205 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483475/205-20-45-10 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483499/205-20-50-7 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5C -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483499/205-20-50-5C Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5B -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483499/205-20-50-5B Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 360 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482099/360-10-50-3 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483475/205-20-45-11 + Details
Name: | us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation
Namespace Prefix: | us-gaap_
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 No definition available. + Details
Name: | us-gaap_LongLivedAssetsHeldForSaleLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=ago_SoundPointAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |