Note 6 - Related-party Transactions - Transactions Between the Company and Affiliates (Details) - USD ($) $ in Thousands		Mar. 31, 2022	Dec. 31, 2021
Due to affiliates		$ 3,333	$ 3,270
Loans Due to Affiliates [Member] | Local Investors in Australia [Member]
Due to affiliates	[1]	656	597
Loans Due to Affiliates [Member] | Local Investors in Mexico [Member]
Due to affiliates	[1]	623	623
Loans Due to Affiliates [Member] | Local Investors Related to Resource Plus [Member]
Due to affiliates	[1]	266	266
Loans Due from Affiliates [Member] | Local Investors in China [Member]
Due from affiliates		$ 1,788	$ 1,784

[1] Represent loans from the local investors into the Company's subsidiaries (representing their proportionate share of working capital loans). The loans have no payment terms and are due on demand and as such have been classified as current liabilities in the Company's consolidated financial statements.