Loans Held for Investment and Loans Held for Investment at Fair Value - Summary of UPB and Amortized Cost Basis of Loans in COVID-19 Forbearance Program (Details) - COVID 19 Forbearance Program - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Jun. 30, 2022	Dec. 31, 2021	Mar. 31, 2022
Accounts Notes And Loans Receivable [Line Items]
UPB Beginning balance	$ 260,709	$ 292,429	$ 392,073
UPB Additions			2,616
UPB Foreclosures	(1,427)	(1,427)	(402)
UPB Repayments	(22,968)	(54,688)	(101,858)
UPB Ending balance	236,314	236,314	292,429
UPB Performing/Accruing, Amount	187,872	187,872	233,307
UPB Nonperforming/Nonaccrual, Amount	$ 48,442	$ 48,442	$ 59,122
UPB Performing/Accruing, Percentage	79.50%	79.50%	79.80%	79.50%
UPB Nonperforming/Nonaccrual, Percentage	20.50%	20.50%	20.20%	20.50%
Amortized Cost Beginning balance	$ 263,860	$ 295,990	$ 396,918
Amortized Cost Additions			2,615
Amortized Cost Foreclosures	(1,438)	(1,438)	(408)
Amortized Cost Repayments	(23,349)	(55,479)	(103,135)
Amortized Cost Ending balance	239,073	239,073	295,990
Amortized Cost Performing/Accruing, Amount	190,101	190,101	236,076
Amortized Cost Nonperforming/Nonaccrual, Amount	$ 48,972	$ 48,972	$ 59,914
Amortized Cost Performing/Accruing, Percentage	79.50%	79.50%	79.80%	79.50%
Amortized Cost Nonperforming/Nonaccrual, Percentage	20.50%	20.50%	20.20%	20.50%