Senior Securities - Summary of Senior Securities (Details) - USD ($)	Jun. 30, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Facility
Line Of Credit Facility [Line Items]
Total Amount Outstanding	$ 7,924	$ 163,169	$ 123,890	$ 154,480	$ 120,454	$ 108,498	$ 82,000	$ 57,000	$ 100,500	$ 124,500
Asset Coverage Per Unit	10,735	5,244	6,906	11,020	9,508	5,812	5,221	6,513	4,056	3,076
Involuntary Liquidating Preference Per Unit	0	0	0	0	0	0	0	0	0	0
Funding Facility I
Line Of Credit Facility [Line Items]
Total Amount Outstanding						158,000	212,000	175,000	175,000	229,000
Asset Coverage Per Unit						5,812	5,221	6,513	4,056	3,076
Involuntary Liquidating Preference Per Unit	0	0	0	0	0	0	0	0	0	0
Funding Facility II
Line Of Credit Facility [Line Items]
Total Amount Outstanding			100,000	0	36,000
Asset Coverage Per Unit			6,906		9,508
Involuntary Liquidating Preference Per Unit	0		0	0	0
Merger Sub Facility
Line Of Credit Facility [Line Items]
Total Amount Outstanding	182,000
Asset Coverage Per Unit	10,735
Involuntary Liquidating Preference Per Unit	0
SBA Debentures
Line Of Credit Facility [Line Items]
Total Amount Outstanding	150,000	150,000	150,000	150,000	138,000	138,000	98,000	83,000	61,000	42,800
Asset Coverage Per Unit	10,735	5,244	6,906	11,020	9,508	5,812	5,221	6,513	4,056	3,076
Involuntary Liquidating Preference Per Unit	0	0	0	0	0	0	0	0	0	0
2019 Convertible Notes
Line Of Credit Facility [Line Items]
Total Amount Outstanding							108,000	108,000	108,000	108,000
Asset Coverage Per Unit							2,157	2,335	2,352	2,429
Involuntary Liquidating Preference Per Unit	0	0	0	0	0	0	0	0	0	$ 0
2022 Convertible Notes
Line Of Credit Facility [Line Items]
Total Amount Outstanding				140,000	140,000	140,000	140,000	140,000	140,000
Asset Coverage Per Unit				1,948	2,058	1,992	2,157	2,335	2,352
Involuntary Liquidating Preference Per Unit		0	0	0	0	0	0	0	$ 0
2022 Notes
Line Of Credit Facility [Line Items]
Total Amount Outstanding					175,000	175,000	175,000	175,000
Asset Coverage Per Unit					2,058	1,992	2,157	2,335
Involuntary Liquidating Preference Per Unit	0	0	0	0	0	0	$ 0	$ 0
2024 Notes
Line Of Credit Facility [Line Items]
Total Amount Outstanding	250,000	250,000	250,000	250,000	250,000	200,000
Asset Coverage Per Unit	1,738	1,643	1,929	1,948	2,058	1,992
Involuntary Liquidating Preference Per Unit	0	0	0	0	$ 0	$ 0
2025 Notes
Line Of Credit Facility [Line Items]
Total Amount Outstanding	92,000
Asset Coverage Per Unit	1,738
Involuntary Liquidating Preference Per Unit	0
2026 Notes
Line Of Credit Facility [Line Items]
Total Amount Outstanding	325,000	325,000	325,000	325,000
Asset Coverage Per Unit	1,738	1,643	1,929	1,948
Involuntary Liquidating Preference Per Unit	0	$ 0	$ 0	$ 0
2029 Notes
Line Of Credit Facility [Line Items]
Total Amount Outstanding	325,000
Asset Coverage Per Unit	1,738
Involuntary Liquidating Preference Per Unit	$ 0