Note 4 - Credit Facilities - Summary of Credit and Other Debt Facilities (Details) $ in Thousands	Dec. 31, 2021 USD ($)
Repayments of Principal, 2022	$ 11,042
Repayments of Principal, 2023	$ 700
North Mill, LLC [Member]
Interest Rate	5.38%
Repayments of Principal, 2022	$ 9,680
USA - Resource Plus Sellers [Member]
Interest Rate	1.87%
Repayments of Principal, 2022	$ 300
Repayments of Principal, 2023	$ 700
National Australia Bank [Member]
Interest Rate	6.76%
Repayments of Principal, 2022	$ 118
People's Bank of China [Member]
Interest Rate	3.71%
Repayments of Principal, 2022	$ 157
Industrial Bank [Member]
Interest Rate	6.17%
Repayments of Principal, 2022	$ 472
Industrial Bank and Commericao Bank of China [Member]
Interest Rate	4.23%
Repayments of Principal, 2022	$ 315
China Construction Bank [Member]
Interest Rate	5.33%
Ve Por Mas [Member]
Interest Rate	7.76%
Bancomer Bank [Member]
Interest Rate	9.92%