Insurance Company Regulatory Requirements - Dividends and Surplus Notes By Insurance Company Subsidiaries (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Statutory Accounting Practices [Line Items]
Dividends paid	$ 68	$ 67	$ 64
Stock redemptions by insurance subsidiaries	502	199	500
Related Party
Statutory Accounting Practices [Line Items]
Stock redemptions by insurance subsidiaries	400	200	0
AG Re \| Assured Guaranty LTD \| Related Party
Statutory Accounting Practices [Line Items]
Dividends paid	97	53	0
AGUK \| AG (U.S. domiciled) \| Related Party
Statutory Accounting Practices [Line Items]
Dividends paid	128	127	0
US Insurance Subsidiaries \| US Holding Companies \| Related Party
Statutory Accounting Practices [Line Items]
Dividends paid	$ 400	$ 358	$ 473

The cash outflow to reacquire common stock during the period.

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