Note 7 - Related Party Transactions (Details Textual) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Oct. 07, 2022
Investment Income, Net	$ 417	$ 499
Gain (Loss) on Investments	3	(3)
Income Taxes Paid	$ 0	$ 76
GAMCO Investors, Inc. [Member]
Investment Expense Rate	0.08%	0.08%
Funds Invested in Mutual Funds	$ 34,702	$ 34,242
Income From Mutual Funds	348	408
Investment Income, Net		408
Gain (Loss) on Investments		0
MtronPTI [Member]
Percentage of Shares Distribution Under Spinoff			100.00%
Salaries and Benefits Reimbursed	26	26
MtronPTI [Member] \| Transitional Administrative and Management Services Agreement [Member]
Monthly Payment	4
Related Party Transaction, Amounts of Transaction	12	12
MtronPTI [Member] \| Tax Indemnity and Sharing Agreement [Member]
Income Taxes Paid	$ 0	$ 0

Amount of funds invested in mutual funds.

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