Borrowings - SBA Debentures Interest Expense and Average Outstanding Balance (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Debt Instrument [Line Items]
Amortization of debt issuance costs			$ 1,134	$ 1,153
Cash paid for interest expense			$ 13,550	$ 15,602
Effective interest rate	6.46%	6.07%	6.39%	5.95%
Average outstanding balance	$ 249,100	$ 323,781	$ 265,043	$ 331,792
SBA Debentures | Debentures
Debt Instrument [Line Items]
Stated interest expense	0	328	151	1,006
Amortization of debt issuance costs	0	43	20	133
Total interest and debt financing costs	0	371	171	1,139
Cash paid for interest expense	$ 0	$ 694	$ 457	$ 1,419
Effective interest rate	0.00%	3.27%	3.26%	3.24%
Average outstanding balance	$ 0	$ 45,311	$ 6,990	$ 46,795