Note 3 - Investments - Portfolio Composition by Industry (Details) - USD ($)	Jun. 30, 2026	Dec. 31, 2025
Investment Owned, Fair Value	$ 262,645,641	$ 262,216,317
Percentage of total investments	100.00%	100.00%
Beef Cattle, Except Feedlots [Member]
Investment Owned, Fair Value	$ 2,955,774	$ 2,955,774
Percentage of total investments	1.10%	1.10%
Boatbuilding and Repairing [Member]
Investment Owned, Fair Value	$ 4,780,946	$ 5,520,952
Percentage of total investments	1.80%	2.10%
Chemicals and Allied Products [Member]
Investment Owned, Fair Value	$ 3,919,175	$ 4,019,175
Percentage of total investments	1.50%	1.50%
Chocolate and Cocoa Products [Member]
Investment Owned, Fair Value	$ 23,514,307	$ 26,475,443
Percentage of total investments	9.00%	10.10%
Coal and Other Minerals and Ores [Member]
Investment Owned, Fair Value	$ 33,234,222	$ 33,577,527
Percentage of total investments	12.70%	12.80%
Computer Related Services, NEC [Member]
Investment Owned, Fair Value	$ 30,806,874	$ 29,092,471
Percentage of total investments	11.70%	11.10%
Corn [Member]
Investment Owned, Fair Value	$ 13,408,445	$ 13,371,613
Percentage of total investments	5.10%	5.10%
Corrugated and Solid Fiber Boxes [Member]
Investment Owned, Fair Value	$ 2,727,088	$ 2,520,135
Percentage of total investments	1.00%	1.00%
Cotton Ginning [Member]
Investment Owned, Fair Value	$ 1,792,698	$ 1,792,698
Percentage of total investments	0.70%	0.70%
Dairy Farms [Member]
Investment Owned, Fair Value	$ 3,919,677	$ 4,252,363
Percentage of total investments	1.50%	1.60%
Electric Services [Member]
Investment Owned, Fair Value	$ 1,403,608	$ 764,426
Percentage of total investments	0.50%	0.30%
Freight Transportation Arrangement [Member]
Investment Owned, Fair Value	$ 3,099,538	$ 3,099,538
Percentage of total investments	1.20%	1.20%
Frozen Fish and Seafood [Member]
Investment Owned, Fair Value	$ 2,390,516	$ 2,674,069
Percentage of total investments	0.90%	1.00%
Hotels and Motels [Member]
Investment Owned, Fair Value	$ 7,728,053	$ 9,885,644
Percentage of total investments	2.90%	3.80%
Land Subdividers and Developers [Member]
Investment Owned, Fair Value	$ 18,473,849	$ 18,029,698
Percentage of total investments	7.00%	6.90%
Motor Vehicle Parts and Accessories [Member]
Investment Owned, Fair Value	$ 9,987,459	$ 11,036,073
Percentage of total investments	3.80%	4.20%
Refuse Systems [Member]
Investment Owned, Fair Value	$ 78,074,055	$ 70,740,611
Percentage of total investments	29.70%	26.90%
Retail Bakeries [Member]
Investment Owned, Fair Value	$ 6,521,990	$ 6,982,214
Percentage of total investments	2.50%	2.70%
Short-Term Business Credit [Member]
Investment Owned, Fair Value	$ 1,777,308	$ 1,777,308
Percentage of total investments	0.70%	0.70%
Soybeans [Member]
Investment Owned, Fair Value	$ 5,944,929	$ 6,040,979
Percentage of total investments	2.30%	2.30%
Towing And Tugboat Service [Member]
Investment Owned, Fair Value	$ 520,357	$ 1,668,687
Percentage of total investments	0.20%	0.60%
Other Industry [Member]
Investment Owned, Fair Value	$ 5,664,773	$ 5,938,919
Percentage of total investments	2.20%	2.30%

Investment Owned, Fair Value

$ 262,645,641

$ 262,216,317