Note 5 - Leases (Details Textual) - USD ($)	1 Months Ended	3 Months Ended	9 Months Ended
	Jan. 31, 2019	Sep. 30, 2019	Sep. 30, 2019	Sep. 30, 2018
Operating Lease, Weighted Average Remaining Lease Term		4 years 255 days	4 years 255 days
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 966,000		$ 966,000
Operating Lease, Payments		$ 74,000	217,000
Operating Lease, Cost		$ 103,000	$ 309,000