Note 10 - Stock Compensation Plans (Details Textual) - USD ($)		1 Months Ended	5 Months Ended	12 Months Ended
		Aug. 30, 2000	Dec. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	May 31, 2022	Aug. 31, 2020	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2013	Aug. 31, 2000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total				$ 0
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)				0	0
The 2003 Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized								450,000
Sharebased Compensation Arrangement By Sharebased Payment Award Number Of Options Ungranted										197,500
The 2015 Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized									750,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)	[1],[2]			0	0
The Directors Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized											200,000
Sharebased Compensation Arrangement By Sharebased Payment Award Number Of Options Ungranted		60,000
Number Of Options Each Director Received At Each Annual Meeting		4,000
Options Vesting Percentage On First And Second Anniversary		50.00%
The Directors Plan [Member] | Director [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)		5,000
The 2011 Non-employee Director Stock Option Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized							200,000
Three Independent Members of the Board of Directors [Member]
Share-Based Compensation Arrangement, Stock to be Granted Per Recipient, Value			$ 50,000
The 2022 Stock Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized						750,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)	[1],[3],[4]			0	0

[1] Indicates plans with stock options.

[2] The 2015 Incentive Stock Plan (the “2015 Plan”) was approved by shareholders in June 2015, which authorizes the issuance of up to 750,000 options to purchase shares of common stock to employees and key consultants and advisors.

[3] In May 2022, shareholders approved the 2022 Employee Stock Incentive Plan (the “2022 Plan”), which replaces the 2015 Plan and authorizes the issuance of 750,000 shares of common stock to employees. No shares have been granted under the plan as of December 31, 2022.

[4] Indicates plans with stock grants.