Note 10 - Leases (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Operating Lease, Right-of-Use Asset	$ 730,000	$ 859,000
Operating Lease, Payments	301,000	291,000
Operating Lease, Cost	450,000	410,000
Operating Lease, Interest Expense	182,000	204,000
Operating Lease, Right-of-Use Asset, Amortization Expense	129,000	108,000
Variable Lease, Cost	111,000	72,000
Short-term Lease, Cost	$ 28,000	$ 26,000
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset			$ 966,000