Note 3 - Net Profits Interest Divestiture (Details Textual) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
Net Profits Interests Divestiture, Consideration	$ 5.7
Trade and Other Receivables [Member]
Net Profits Interests Divestiture, Consideration, Holdbacks	0.2
General and Administrative Expense [Member]
Net Profits Interests Divestiture Transaction Costs	$ 0.5