Note 3 - Revenue From Contracts With Customers - Changes in Contract Assets and Liabilities (Details) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024
Balance at December 31, 2023	$ 85,035	$ 114,540	$ 127,091	$ 182,756	$ 114,540
Contract liabilities added	1,732	26,026
Revenue recognized		(55,531)	(55,088)	(55,665)	(31,237)
Balance at March 31, 2024	$ 55,531	$ 85,035	$ 72,003	$ 127,091	$ 55,531