Note 5 - Leases (Details Textual) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2019	Jan. 01, 2019
Operating Lease, Right-of-Use Asset	$ 765,000	$ 765,000	$ 859,000
Operating Lease, Payments		225,000
Operating Lease, Cost	$ 135,000	$ 343,000
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset				$ 966,000