Note 6 - Fair Value - Reconciliation of Level 3 Assets (Details) - USD ($)		12 Months Ended
		Dec. 31, 2025		Dec. 31, 2024
Unrealized appreciation (depreciation)		$ 116,619		$ 9,611,866
Fair Value, Inputs, Level 3 [Member]
Fair value, balance		315,250		4,797,872
Purchases		0		2,441
Sales		(8,623)		(6,272,666)
Realized gains (losses)		(26,070,392)		(11,686,668)
Unrealized appreciation (depreciation)		25,932,930	[1]	9,611,866	[2]
Transfers		0		3,862,405
Fair value, balance		169,165		315,250
Common Stock [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value, balance		260,497		299,987
Purchases		0		0
Sales		0		0
Realized gains (losses)		(20,000)		0
Unrealized appreciation (depreciation)		(72,855)	[1]	(3,901,895)	[2]
Transfers		0		3,862,405
Fair value, balance		167,642		260,497
Common Stock [Member] | Advanced Materials Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value, balance		260,497		299,932
Purchases		0		0
Sales		0		0
Realized gains (losses)		0		0
Unrealized appreciation (depreciation)		(92,855)	[1]	(39,435)	[2]
Transfers		0		0
Fair value, balance		167,642		260,497
Common Stock [Member] | Equipment Leasing Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value, balance		0		55
Purchases		0		0
Sales		0		0
Realized gains (losses)		(20,000)		0
Unrealized appreciation (depreciation)		20,000	[1]	(55)	[2]
Transfers		0		0
Fair value, balance		0		0
Common Stock [Member] | Semiconductor Equipment Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value, balance		0		0
Purchases				0
Sales				0
Realized gains (losses)				0
Unrealized appreciation (depreciation)	[2]			(3,862,405)
Transfers				3,862,405
Fair value, balance				0
Common Stock [Member] | Automotive Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value, balance		0		0
Purchases				0
Sales				(40,000)
Realized gains (losses)				0
Unrealized appreciation (depreciation)	[2]			40,000
Transfers				0
Fair value, balance				0
Preferred Stock [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value, balance		29,466		110,172
Purchases		0		2,441
Sales		(8,623)		(176,405)
Realized gains (losses)		(1,921,377)		(11,083,138)
Unrealized appreciation (depreciation)		1,900,534	[1]	11,176,396	[2]
Transfers		0		0
Fair value, balance		0		29,466
Preferred Stock [Member] | Equipment Leasing Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value, balance		29,466		110,172
Purchases		0		0
Sales		(8,623)		(20,000)
Realized gains (losses)		(1,921,377)		0
Unrealized appreciation (depreciation)		1,900,534	[1]	(60,706)	[2]
Transfers		0		0
Fair value, balance		0		29,466
Preferred Stock [Member] | Aerospace Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value, balance		0		0
Purchases				2,441
Sales				(156,405)
Realized gains (losses)				(11,083,138)
Unrealized appreciation (depreciation)	[2]			11,237,102
Transfers				0
Fair value, balance				0
Debt [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value, balance		25,287
Purchases		0
Sales		0
Realized gains (losses)		(24,129,015)
Unrealized appreciation (depreciation)	[1]	24,105,251
Transfers		0
Fair value, balance		1,523		25,287
Debt [Member] | Automotive Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value, balance		0
Purchases		0
Sales		0
Realized gains (losses)		(24,129,015)
Unrealized appreciation (depreciation)	[1]	24,129,015
Transfers		0
Fair value, balance		0		0
Debt [Member] | Medical Devices Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value, balance		25,287
Purchases		0
Sales		0
Realized gains (losses)		0
Unrealized appreciation (depreciation)	[1]	(23,764)
Transfers		0
Fair value, balance		1,523		25,287
Convertible Debt [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value, balance		25,287		4,387,713
Purchases				0
Sales				(6,096,261)
Realized gains (losses)				(603,530)
Unrealized appreciation (depreciation)	[2]			2,337,365
Transfers				0
Fair value, balance				25,287
Convertible Debt [Member] | Advanced Materials Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value, balance		0		100,000
Purchases				0
Sales				(100,000)
Realized gains (losses)				0
Unrealized appreciation (depreciation)	[2]			0
Transfers				0
Fair value, balance				0
Convertible Debt [Member] | Aerospace Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value, balance		0		4,200,000
Purchases				0
Sales				(5,956,261)
Realized gains (losses)				(603,530)
Unrealized appreciation (depreciation)	[2]			2,359,791
Transfers				0
Fair value, balance				0
Convertible Debt [Member] | Medical Devices Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Fair value, balance		$ 25,287		87,713
Purchases				0
Sales				0
Realized gains (losses)				0
Unrealized appreciation (depreciation)	[2]			(62,426)
Transfers				0
Fair value, balance				$ 25,287

[1] The net change in unrealized appreciation (depreciation) from Level 3 instruments held as of December 31, 2025 was $(116,619).

[2] The net change in unrealized appreciation (depreciation) from Level 3 instruments held as of December 31, 2024 was $9,611,866