XML 110 R86.htm IDEA: XBRL DOCUMENT
v3.24.1.u1

Income Taxes - Deferred and Current Tax Liabilities (Details) - USD ($) $ in Millions | Mar. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Income Tax Disclosure [Abstract] |  |
Net deferred tax assets (liabilities) | $ 256 | $ 250
Net current tax assets (liabilities) | $ (39) | $ (9)

X
- Definition Deferred Tax Assets (Liabilities), Net, Current1 + References No definition available. + Details
Name: | ago_DeferredTaxAssetsLiabilitiesNetCurrent1
Namespace Prefix: | ago_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, without jurisdictional netting. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-2 + Details
Name: | us-gaap_DeferredTaxAssetsLiabilitiesNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_IncomeTaxDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration