Financial Guaranty Variable Interest Entities and Consolidated Investment Vehicles - Schedule of Redeemable Noncontrolling Interest of Consolidated Investment Vehicle (Details) - Variable Interest Entity, Primary Beneficiary - Consolidated Investment Vehicles - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Redeemable Noncontrolling Interest, Equity, Other, Fair Value, Rollforward [Roll Forward]
Beginning balance	$ 22	$ 21	$ 7
Net income (loss) attributable to the redeemable NCI	(1)	1	(1)
Reallocation of ownership interests	0	0	(10)
Reclassification to liabilities as mandatorily redeemable NCI	(21)	0	0
Contributions	21	0	25
Distributions	(21)	0	0
Ending balance	$ 0	$ 22	$ 21