Goodwill and Other Intangible Assets - Schedule of Finite-lived Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 0	$ 117
Finite-lived intangible assets, gross	1	82
Accumulated amortization	(1)	(42)
Finite-lived intangible assets, net	0	40
Indefinite-lived intangible assets (insurance licenses)	6	6
Total goodwill and other intangible assets	6	163
Assured IM
Finite-Lived Intangible Assets [Line Items]
Total goodwill and other intangible assets	$ 0
CLO Contracts
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross		$ 42
CLO Contracts | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life		1 year 2 months 12 days
Investment Management Contracts
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross		$ 24
Investment Management Contracts | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life		6 years 9 months 18 days