Loans Held for Investment and the Allowance for Credit Losses - Summary of Loans Held for Investment Portfolio Activity (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($)
Loans and Leases Receivable, Related Parties [Roll Forward]
Balance as of January 1, 2023	$ 4,781,402
Loans originated and acquired	109,922
Additional fundings	84,544
Amortization of origination fees and discounts	7,705
Collection of principal	(503,244)
Collection of accrued PIK interest	(542)
Collection of interest applied to reduce principal under the cost-recovery method	(3,167)
Loan sale	(71,269)
Loan extinguishment upon conversion to REO	(55,029)
Increase of allowance for credit losses	(52,972)
Balance as of March 31, 2023	$ 4,297,350