Note 7 - Related Party Transactions (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Jun. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023	Oct. 07, 2022
Investment Income, Net	$ 531	$ 544		$ 1,568	$ 1,017
Gain (Loss) on Investments	$ (2)	$ (4)		(6)	384
Income Taxes Paid				$ 76	$ 207
GAMCO Investors, Inc. [Member]
Investment Expense Rate	0.08%	0.08%		0.08%	0.16%
Funds Invested in Mutual Funds	$ 33,931			$ 33,931		$ 32,568
Income From Mutual Funds	444	$ 350		1,293	$ 1,172
Investment Income, Net					802
Gain (Loss) on Investments					370
MtronPTI [Member]
Percentage of Shares Distribution Under Spinoff							100.00%
Salaries and Benefits Reimbursed	27			80
Excess Separation Costs			$ 28
MtronPTI [Member] | Transitional Administrative and Management Services Agreement [Member]
Monthly Payment	4			4
Related Party Transaction, Amounts of Transaction	12	12		36	36
MtronPTI [Member] | Tax Indemnity and Sharing Agreement [Member]
Income Taxes Paid	$ 0	$ 0		$ 0	$ 0