Note 5 - Investments - Major Categories of Net Interest and Dividend Income (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Short term investments and cash and cash equivalents	$ 352	$ 1,400	$ 1,122	$ 1,452
Net investment income	$ 352	$ 1,400	$ 1,122	$ 1,452