Note 6 - Fair Value - Schedule of Balance Sheet Grouping (Details) - USD ($)		Sep. 30, 2025	Dec. 31, 2024
Investments, fair value		$ 256,934	$ 1,060,474
Fair Value, Inputs, Level 1 [Member]
Investments, fair value		59,009
Fair Value, Inputs, Level 2 [Member]
Investments, fair value		0
Fair Value, Inputs, Level 3 [Member]
Investments, fair value		197,925
Advanced Materials Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Investments, fair value	[1]	0.2
Equipment Leasing Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Investments, fair value		0
Medical Devices Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Investments, fair value		0
Common Stock [Member] | Fair Value, Inputs, Level 1 [Member]
Investments, fair value		0
Common Stock [Member] | Fair Value, Inputs, Level 2 [Member]
Investments, fair value		0
Common Stock [Member] | Fair Value, Inputs, Level 3 [Member]
Investments, fair value		171,528
Common Stock [Member] | Advanced Materials Sector [Member] | Fair Value, Inputs, Level 1 [Member]
Investments, fair value		0
Common Stock [Member] | Advanced Materials Sector [Member] | Fair Value, Inputs, Level 2 [Member]
Investments, fair value		0
Common Stock [Member] | Advanced Materials Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Investments, fair value		171,528
Preferred Stock [Member] | Fair Value, Inputs, Level 1 [Member]
Investments, fair value		0
Preferred Stock [Member] | Fair Value, Inputs, Level 2 [Member]
Investments, fair value		0
Preferred Stock [Member] | Fair Value, Inputs, Level 3 [Member]
Investments, fair value		23,173
Preferred Stock [Member] | Equipment Leasing Sector [Member] | Fair Value, Inputs, Level 1 [Member]
Investments, fair value		0
Preferred Stock [Member] | Equipment Leasing Sector [Member] | Fair Value, Inputs, Level 2 [Member]
Investments, fair value		0
Preferred Stock [Member] | Equipment Leasing Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Investments, fair value		23,173
Debt [Member] | Fair Value, Inputs, Level 1 [Member]
Investments, fair value		0
Debt [Member] | Fair Value, Inputs, Level 2 [Member]
Investments, fair value		0
Debt [Member] | Fair Value, Inputs, Level 3 [Member]
Investments, fair value		3,224
Debt [Member] | Medical Devices Sector [Member] | Fair Value, Inputs, Level 1 [Member]
Investments, fair value		0
Debt [Member] | Medical Devices Sector [Member] | Fair Value, Inputs, Level 2 [Member]
Investments, fair value		0
Debt [Member] | Medical Devices Sector [Member] | Fair Value, Inputs, Level 3 [Member]
Investments, fair value		3,224
Mutual Fund [Member] | Fair Value, Inputs, Level 1 [Member]
Investments, fair value		59,009
Mutual Fund [Member] | Fair Value, Inputs, Level 2 [Member]
Investments, fair value		0
Mutual Fund [Member] | Fair Value, Inputs, Level 3 [Member]
Investments, fair value		$ 0

[1] An increase in the input would result in an increase in the security’s valuation; a decrease in the input would result in a decrease in the security’s valuation.