Note 2 - Revenue from Contracts with Customers (Details Textual) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Contract with Customer, Asset, Net, Current, Total	$ 498,681	$ 498,681	$ 0
Contract with Customer, Liability, Current	486,362	486,362	318,552
Contract with Customer, Liability, Revenue Recognized	63,366	318,552
Capitalized Contract Cost, Net, Total	0	0	3,480
Prepaid Expenses and Other Current Assets [Member]
Deferred Costs of Revenue	$ 532,791	$ 532,791	$ 294,115