Note 12 - Contingencies and Commitments (Details Textual) - USD ($)	3 Months Ended						6 Months Ended
	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2023
Statement [Line Items]
Dividends, Common Stock, Cash	$ 329,000	$ 335,000	$ 335,000	$ 337,000	$ 338,000	$ 338,000
Monthly Dividend [Member] | Forecast [Member]
Statement [Line Items]
Common Stock, Dividends, Per Share, Declared (in dollars per share)							$ 0.0075
Dividends, Common Stock, Cash							$ 332,000