Note 8 - Leases - Lease Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Operating lease right-of-use assets	$ 200	$ 395
Accrued Liabilities [Member]
Current operating lease liabilities	203	268
Other Noncurrent Liabilities [Member]
Noncurrent operating lease liabilities		132
Accrued Liabilities and Other Noncurrent Liabilities [Member]
Operating Lease, Liability, Total	$ 203	$ 400