Note 8 - Commitments and Contingencies (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Purchase Obligation, Total	$ 5.6
Selling, General and Administrative Expenses [Member]
Operating Lease, Expense	0.2	$ 0.3
Cost of Sales [Member]
Operating Lease, Expense	$ 0.8	$ 0.8