Note 6 - Leases (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jan. 01, 2019
Operating Lease, Liability, Total	$ 328,000		$ 328,000
Operating Lease, Weighted Average Discount Rate, Percent	5.00%		5.00%
Lessee, Operating Lease, Liability, Payments, Due, Total	$ 347,000		$ 347,000
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	$ 19,000		$ 19,000
Operating Lease, Weighted Average Remaining Lease Term	2 years 73 days		2 years 73 days
Operating Leases, Rent Expense, Net, Total		$ 92,000		$ 275,000
Variable Lease, Cost	$ 10,000	$ 10,000	$ 32,000	$ 28,000
Operating Lease, Payments	71,000		247,000
Other Assets [Member]
Operating Lease, Right-of-Use Asset	328,000		328,000
Other Liabilities [Member]
Operating Lease, Liability, Total	$ 328,000		$ 328,000
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset					$ 565,000
Operating Lease, Liability, Total					$ 565,000