Financial Guaranty Variable Interest Entities and Consolidated Investment Vehicles - Number of Consolidated CIVs by Type (Details) - Variable Interest Entity, Primary Beneficiary - Consolidated Investment Vehicles	3 Months Ended
	Mar. 31, 2023 consolidatedCLO cLOWarehouse consolidatedInvestmentVehicle Entity consolidatedInvestmentFund	Dec. 31, 2022 cLOWarehouse consolidatedCLO consolidatedInvestmentVehicle consolidatedInvestmentFund
Variable Interest Entity [Line Items]
Total number of entities consolidated | consolidatedInvestmentVehicle	21	22
Number of entities deconsolidated in the period | Entity	1
Investment Managed Funds
Variable Interest Entity [Line Items]
Total number of entities consolidated | consolidatedInvestmentFund	7	8
Collateralized Loan Obligations
Variable Interest Entity [Line Items]
Total number of entities consolidated | consolidatedCLO	10	10
Collateralized Loan Obligation Warehouses
Variable Interest Entity [Line Items]
Total number of entities consolidated | cLOWarehouse	4	4