Note 13 - Fair Value Measurements - Schedule of Carrying Value and Fair Value by Fair Value Hierarchy of Financial Instruments (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Warrant [Member]
Derivative liability, fair value	$ 84	$ 31
Warrant [Member] | Fair Value, Inputs, Level 1 [Member]
Derivative liability, fair value
Warrant [Member] | Fair Value, Inputs, Level 2 [Member]
Derivative liability, fair value
Warrant [Member] | Fair Value, Inputs, Level 3 [Member]
Derivative liability, fair value	84	31
Palladium and Finished Goods Inventory [Member]
Inventory, fair value	880
Palladium and Finished Goods Inventory [Member] | Fair Value, Inputs, Level 1 [Member]
Inventory, fair value	264
Palladium and Finished Goods Inventory [Member] | Fair Value, Inputs, Level 2 [Member]
Inventory, fair value	616
Palladium and Finished Goods Inventory [Member] | Fair Value, Inputs, Level 3 [Member]
Inventory, fair value
Corn, Palladium and Finished Goods [Member]
Inventory, fair value		866
Corn, Palladium and Finished Goods [Member] | Fair Value, Inputs, Level 1 [Member]
Inventory, fair value		235
Corn, Palladium and Finished Goods [Member] | Fair Value, Inputs, Level 2 [Member]
Inventory, fair value		631
Corn, Palladium and Finished Goods [Member] | Fair Value, Inputs, Level 3 [Member]
Inventory, fair value