Note 5 - Related-party Transactions - Transactions Between the Company and Affiliates (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Services provided by affiliates		$ 808	$ 8,046	$ 1,476	$ 16,574
Due to affiliates		4,520		4,520		$ 4,645
Loans Due to Affiliates [Member] | Local Investors in Australia [Member]
Due to affiliates	[1]	428		428		226
Loans Due to Affiliates [Member] | Local Investors in Mexico [Member]
Due to affiliates	[1]	1,001		1,001		1,001
Loans Due to Affiliates [Member] | Local Investors in Brazil [Member]
Due to affiliates	[1]	139		139		139
Loans Due to Affiliates [Member] | Local Investors in China [Member]
Due to affiliates	[1]	1,803		1,803		2,130
Loans Due to Affiliates [Member] | Local Investors In South Africa [Member]
Due to affiliates	[1]	618		618		618
Loans Due to Affiliates [Member] | Local Investors Related to Resource Plus [Member]
Due to affiliates	[1]	531		531		$ 531
Field Specialist Expenses SBS [Member]
Services provided by affiliates	[2]		6,561		13,290
Field Administration Expenses SAS [Member]
Services provided by affiliates	[2]		1,113		2,262
NSRS [Member]
Services provided by affiliates		260		385
RJ Holdings [Member]
Services provided by affiliates		97	143	199	285
Office And Vehicle Rental MPT [Member]
Services provided by affiliates		16	6	32	25
Vehicle Rental MCPT [Member]
Services provided by affiliates		297	118	587	457
Office And Vehicle Rental MHT [Member]
Services provided by affiliates		68	9	132	62
Consulting and Administrative Services (CON) [Member]
Services provided by affiliates		37	56	74	115
Legal Services (KMSA) [Member]
Services provided by affiliates		21	28	43	54
Warehouse Rental (JFMD) [Member]
Services provided by affiliates		$ 12	$ 12	$ 24	$ 24

[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.

[2] Includes substantially all overhead (in the case of SAS and SBS), or related overhead, plus any applicable markup. The services provided by SAS and SBS were terminated as of July 2018.