Note 8 - Marketable Securities (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Other-than-temporary Impairment Loss, Debt Securities, Available-for-Sale			$ 0	$ 0
Investment Income, Nonoperating	$ 20,000	$ 35,000	$ 101,000	$ 74,000