Note 13 - Accrued Liabilities - Components of Other Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Contract liabilities (Note 3)	$ 787	$ 850
Accrued remediation contingency (Note 14)	50	176
Other accrued liabilities	743	1,073
Total other accrued liabilities	$ 1,580	$ 2,099