Insurance Company Regulatory Requirements - Dividends and Surplus Notes By Insurance Company Subsidiaries (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statutory Accounting Practices [Line Items]
Dividends paid	$ 67	$ 64	$ 66
Redemption of common stock by AGC from AGUS	199	500	496
AGC \| AGC \| Related Party
Statutory Accounting Practices [Line Items]
Dividends paid	102	207	94
Redemption of common stock by AGC from AGUS	200	0	0
Assured Guaranty Municipal Corp \| AGMH \| Related Party
Statutory Accounting Practices [Line Items]
Dividends paid	257	266	291
AG Re \| Assured Guaranty LTD
Statutory Accounting Practices [Line Items]
Dividend from a subsidiary in the form of fixed-maturity securities	0	0	46
AG Re \| Assured Guaranty LTD \| Related Party
Statutory Accounting Practices [Line Items]
Dividends paid	53	0	150
AGUK \| Assured Guaranty Municipal Corp \| Related Party
Statutory Accounting Practices [Line Items]
Dividends paid	$ 127	$ 0	$ 0

The cash outflow to reacquire common stock during the period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-15

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Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests.

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Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.

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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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(23)(c))
-Publisher FASB
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