Note 2 - Basis of Presentation and Revenue Recognition Policy (Details Textual) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Contract with Customer, Liability, Current	$ 6,475,000		[1]

[1] The condensed consolidated balance sheet as of December 31, 2019 has been prepared using information from the audited consolidated balance sheet as of that date.