Note 12 - Accrued Liabilities - Components of Other Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Contract liabilities (Note 3)	$ 357	$ 712
Accrued remediation contingency (Note 13)	238	146
Other accrued liabilities	971	1,118
Total other accrued liabilities	$ 1,566	$ 1,976