PORTFOLIO INVESTMENTS AND FAIR VALUE - Geographical concentration of investment portfolio (Details) - USD ($)	Sep. 30, 2022	Dec. 31, 2021
Investment Holdings [Line Items]
Investments, amortized cost	$ 899,059,872	$ 785,005,957
Fair value of investments	$ 871,733,280	772,873,326
% of Total Investments at fair value	100.00%
Texas
Investment Holdings [Line Items]
Fair value of investments	$ 179,543,296	$ 142,657,160
% of Total Investments at fair value	20.60%	18.46%
California
Investment Holdings [Line Items]
Fair value of investments	$ 159,142,278	$ 157,446,299
% of Total Investments at fair value	18.26%	20.37%
Illinois
Investment Holdings [Line Items]
Fair value of investments	$ 60,270,478	$ 71,066,882
% of Total Investments at fair value	6.91%	9.20%
Florida
Investment Holdings [Line Items]
Fair value of investments	$ 55,461,152	$ 13,220,344
% of Total Investments at fair value	6.36%	1.71%
Arizona
Investment Holdings [Line Items]
Fair value of investments	$ 43,543,647	$ 31,117,284
% of Total Investments at fair value	4.99%	4.03%
Pennsylvania
Investment Holdings [Line Items]
Fair value of investments	$ 41,965,443	$ 42,604,002
% of Total Investments at fair value	4.81%	5.51%
Washington
Investment Holdings [Line Items]
Fair value of investments	$ 28,411,087	$ 40,790,941
% of Total Investments at fair value	3.26%	5.28%
Ohio
Investment Holdings [Line Items]
Fair value of investments	$ 37,284,222	$ 38,218,517
% of Total Investments at fair value	4.28%	4.94%
Wisconsin
Investment Holdings [Line Items]
Fair value of investments	$ 32,737,796	$ 25,893,643
% of Total Investments at fair value	3.75%	3.35%
New Jersey
Investment Holdings [Line Items]
Fair value of investments	$ 25,077,935	$ 23,548,670
% of Total Investments at fair value	2.88%	3.05%
District Of Columbia
Investment Holdings [Line Items]
Fair value of investments	$ 20,718,474	$ 13,137,892
% of Total Investments at fair value	2.38%	1.70%
Georgia
Investment Holdings [Line Items]
Fair value of investments	$ 19,016,228	$ 19,045,442
% of Total Investments at fair value	2.18%	2.46%
United Kingdom
Investment Holdings [Line Items]
Fair value of investments	$ 16,880,158	$ 19,537,231
% of Total Investments at fair value	1.94%	2.53%
South Carolina
Investment Holdings [Line Items]
Fair value of investments	$ 19,020,058	$ 13,270,530
% of Total Investments at fair value	2.18%	1.71%
Maryland
Investment Holdings [Line Items]
Fair value of investments	$ 16,738,333	$ 16,974,999
% of Total Investments at fair value	1.92%	2.20%
Minnesota
Investment Holdings [Line Items]
Fair value of investments	$ 15,915,549	$ 15,688,073
% of Total Investments at fair value	1.83%	2.03%
Colorado
Investment Holdings [Line Items]
Fair value of investments	$ 14,555,303	$ 14,980,283
% of Total Investments at fair value	1.67%	1.94%
Indiana
Investment Holdings [Line Items]
Fair value of investments	$ 14,334,657
% of Total Investments at fair value	1.64%
Canada
Investment Holdings [Line Items]
Fair value of investments	$ 13,244,350	$ 13,265,324
% of Total Investments at fair value	1.52%	1.71%
New York
Investment Holdings [Line Items]
Fair value of investments	$ 15,055,505	$ 27,334,823
% of Total Investments at fair value	1.73%	3.54%
Idaho
Investment Holdings [Line Items]
Fair value of investments	$ 10,238,234
% of Total Investments at fair value	1.17%
North Carolina
Investment Holdings [Line Items]
Fair value of investments	$ 10,621,949	$ 10,360,521
% of Total Investments at fair value	1.22%	1.34%
Massachusetts
Investment Holdings [Line Items]
Fair value of investments	$ 10,567,200	$ 10,348,341
% of Total Investments at fair value	1.21%	1.34%
Missouri
Investment Holdings [Line Items]
Fair value of investments	$ 10,117,698	$ 10,600,866
% of Total Investments at fair value	1.16%	1.37%
Virginia
Investment Holdings [Line Items]
Fair value of investments	$ 1,100,000	$ 616,212
% of Total Investments at fair value	0.13%	0.08%
Michigan
Investment Holdings [Line Items]
Fair value of investments	$ 172,250
% of Total Investments at fair value	0.02%
Puerto Rico
Investment Holdings [Line Items]
Fair value of investments		$ 1,149,047
% of Total Investments at fair value		0.15%