Components of Operating Expenses - Components of General and Administrative Expenses and Other Expenses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Business Acquisition [Line Items]
Fixed compensation expense	$ 15,359	$ 14,628
Annual variable compensation expense	4,005	3,357
Long-term incentive award expense	7,942	5,660
Systems and consulting	3,112	3,184
Office costs	2,040	2,025
Accounting and legal	919	1,675
Corporate costs	929	864
Other	1,249	1,883
Total General and Administrative Expenses	35,555	33,276
Portfolio Management Costs	3,510	1,578
Loan Acquisition Costs	1,289	4,465
Amortization of purchase-related intangible assets	3,107	3,534
Other	577	551
Total Other Expenses	3,684	4,085
Total Operating Expenses	44,038	43,404
Severance and transition-related expenses	1,000
Settlement in Common Stock
Business Acquisition [Line Items]
Long-term incentive award expense	6,000	5,000
Settlement in Cash
Business Acquisition [Line Items]
Long-term incentive award expense	$ 2,000	$ 1,000