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Business and Basis of Presentation (Details) $ in Millions			1 Months Ended	3 Months Ended		6 Months Ended
	Aug. 05, 2024 USD ($)	Jul. 01, 2023 rISK	May 31, 2024 USD ($)	Jun. 30, 2024 USD ($) Company	Jun. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)
Long-Lived Assets Held-for-sale [Line Items]
Number of holding companies with outstanding public debt | Company				2
Assured Guaranty Municipal Corp.
Long-Lived Assets Held-for-sale [Line Items]
Stock redeemed or during period			$ 100
Subsequent Event | AGC
Long-Lived Assets Held-for-sale [Line Items]
Stock redeemed or during period	$ 300
Proceeds in exchange for redemption of common stock	$ 172
Consolidated Investment Vehicles
Long-Lived Assets Held-for-sale [Line Items]
Number of remaining CIVs | rISK		3
Disposal Group, Held-for-sale, Not Discontinued Operations
Long-Lived Assets Held-for-sale [Line Items]
Assets held for sale				$ 28
Liabilities held for sale				$ 2
Disposal Group, Held-for-sale, Not Discontinued Operations | Sound Point Agreement
Long-Lived Assets Held-for-sale [Line Items]
Participation percentage		30.00%
Term to make new investments				2 years
Term to reinvest all returns of capital		15 years
Expenses recognized					$ 24	$ 31

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