Note 3 - Revenue from Contracts with Customers (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Accounts Receivable, Allowance for Credit Loss, Ending Balance	$ 0		$ 0		$ 0
Contract with Customer, Liability, Revenue Recognized	55,088	$ 55,168	110,753	$ 111,591
Capitalized Contract Cost, Net	$ 0		$ 0		$ 0