Variable Interest Entities - Income and Expense Amounts Related to the Consolidated VIE (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]
Interest income	$ 23,900	$ 30,148	$ 71,403	$ 86,959
Interest expense, non-recourse liabilities	(16,490)	(18,408)	(50,742)	(41,849)
NET INTEREST INCOME	7,410	11,740	20,661	45,110
VIE - Primary Beneficiary
Variable Interest Entity [Line Items]
Interest income	15,733	12,759	41,213	34,646
Interest expense, non-recourse liabilities	(10,956)	(6,983)	(26,121)	(17,245)
NET INTEREST INCOME	4,777	5,776	15,092	17,401
Net unrealized gain (loss) on mortgage loans in securitization trusts - at fair value	(16,863)	(73,178)	(9,404)	(152,931)
Unrealized gain (loss) on mark-to-market of non-recourse securitization obligation - at fair value	22,183	34,357	3,620	67,030
Securitization costs	(416)	(1,115)	(2,326)	(3,405)
Realized losses and operating expenses	(967)	(247)	(2,163)	(695)
Net gain/(loss) from consolidated VIEs	$ 8,714	$ (34,407)	$ 4,819	$ (72,600)