Note 9 - Segment Information - Geographic Data (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net revenues	$ 50,944	$ 68,223	$ 112,292	$ 125,383
BRAZIL
Net revenues	$ 10,539	$ 16,612	$ 26,103	$ 32,145
BRAZIL | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	20.70%	24.30%	23.20%	25.60%
SOUTH AFRICA
Net revenues	$ 6,088	$ 6,442	$ 13,002	$ 12,976
SOUTH AFRICA | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	12.00%	9.40%	11.60%	10.30%
MEXICO
Net revenues	$ 4,820	$ 5,664	$ 10,667	$ 10,951
MEXICO | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	9.50%	8.30%	9.50%	8.70%
CHINA
Net revenues	$ 2,756	$ 3,180	$ 5,320	$ 6,459
CHINA | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	5.40%	4.70%	4.70%	5.20%
INDIA
Net revenues	$ 1,915	$ 2,065	$ 4,207	$ 4,271
INDIA | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	3.80%	3.00%	3.70%	3.40%
JAPAN
Net revenues	$ 1,649	$ 2,865	$ 4,431	$ 5,595
JAPAN | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	3.20%	4.20%	3.90%	4.50%
CANADA
Net revenues	$ 1,004	$ 2,459	$ 2,720	$ 4,563
CANADA | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	2.00%	3.60%	2.40%	3.60%
AUSTRALIA
Net revenues	$ 50	$ 863	$ 430	$ 1,627
AUSTRALIA | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	0.10%	1.30%	0.40%	1.30%
TURKEY
Net revenues		$ 67		$ 134
TURKEY | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue		0.10%		0.10%
International [Member]
Net revenues	$ 28,821	$ 40,217	$ 66,880	$ 78,721
International [Member] | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	56.70%	58.90%	59.40%	62.70%