Consolidated Securitization Vehicles and Other Variable Interest Entities - Income, OTTI and Expense Amounts Related to Consolidated VIEs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Variable Interest Entity [Line Items]
Net interest income	$ 63,398	$ 104,839	$ 198,712	$ 359,432
(Increase) decrease in provision for credit losses			(9,041)	(3,203)
Servicing and asset manager fees	8,139	8,516	24,965	27,122
Variable Interest Entities, Primary Beneficiary
Variable Interest Entity [Line Items]
(Increase) decrease in provision for credit losses	(1,560)	2,284	(3,519)	(859)
Servicing and asset manager fees	7,199	6,701	21,403	20,256
Non Agency Residential Mortgage Backed Securities And Securitized Loans | Variable Interest Entities, Primary Beneficiary
Variable Interest Entity [Line Items]
Interest income, Assets of consolidated VIEs	153,710	139,598	443,286	410,873
Interest expense, Non-recourse liabilities of VIEs	75,902	50,030	208,678	142,714
Net interest income	$ 77,808	$ 89,568	$ 234,608	$ 268,159