Note 9 - Segment Information - Geographic Data (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net revenues	$ 58,865	$ 66,440	$ 171,157	$ 191,823
BRAZIL
Net revenues	$ 11,252	$ 16,829	$ 37,355	$ 48,974
BRAZIL | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	19.10%	25.30%	21.80%	25.50%
SOUTH AFRICA
Net revenues	$ 6,325	$ 6,589	$ 19,327	$ 19,565
SOUTH AFRICA | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	10.70%	9.90%	11.30%	10.20%
MEXICO
Net revenues	$ 5,006	$ 5,676	$ 15,673	$ 16,627
MEXICO | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	8.50%	8.50%	9.20%	8.70%
CHINA
Net revenues	$ 3,019	$ 2,889	$ 8,339	$ 9,348
CHINA | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	5.10%	4.30%	4.90%	4.90%
JAPAN
Net revenues	$ 2,335	$ 2,777	$ 6,766	$ 8,372
JAPAN | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	4.00%	4.20%	4.00%	4.40%
INDIA
Net revenues	$ 2,128	$ 2,267	$ 6,335	$ 6,538
INDIA | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	3.60%	3.40%	3.70%	3.40%
CANADA
Net revenues	$ 1,571	$ 2,107	$ 4,291	$ 6,670
CANADA | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	2.70%	3.20%	2.50%	3.50%
AUSTRALIA
Net revenues	$ 188	$ 759	$ 618	$ 2,386
AUSTRALIA | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	0.30%	1.10%	0.40%	1.20%
TURKEY
Net revenues		$ 67		$ 201
TURKEY | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue		0.10%		0.10%
International [Member]
Net revenues	$ 31,824	$ 39,960	$ 98,704	$ 118,681
International [Member] | Geographic Concentration Risk [Member] | Revenue Benchmark [Member]
Percent of consolidated net revenue	54.00%	60.00%	57.80%	61.90%