Note 2 - Accounts Receivable - Allowance for Doubtful Accounts (Details) - USD ($)	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Allowance for credit losses, beginning of period	$ 73,728	$ 68,620
Current period provision	(8,236)	(3,936)
Write-off	(856)	0
Allowance for credit losses, end of period	$ 64,636	$ 64,684