Note 1 - Business Description and Significant Accounting Policies - Schedule of Accounts Receivable (Details) - USD ($)	Dec. 31, 2024	Dec. 31, 2023
Accounts receivable	$ 186,000	$ 577,000
Allowance for estimated credit losses	0	(153,000)
Accounts receivable, net	$ 186,000	$ 424,000