Note 10 - Segment Information - Geographic Data (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Net revenues	$ 58,994	$ 61,097
Revenue Benchmark [Member] | Geographic Concentration Risk [Member]
Percent of consolidated net revenue	100.00%	100.00%
UNITED STATES
Net revenues	$ 23,353	$ 23,676
UNITED STATES | Revenue Benchmark [Member] | Geographic Concentration Risk [Member]
Percent of consolidated net revenue	39.70%	38.80%
BRAZIL
Net revenues	$ 15,568	$ 12,300
BRAZIL | Revenue Benchmark [Member] | Geographic Concentration Risk [Member]
Percent of consolidated net revenue	26.40%	20.10%
SOUTH AFRICA
Net revenues	$ 9,198	$ 7,722
SOUTH AFRICA | Revenue Benchmark [Member] | Geographic Concentration Risk [Member]
Percent of consolidated net revenue	15.60%	12.60%
MEXICO
Net revenues	$ 2,410	$ 7,259
MEXICO | Revenue Benchmark [Member] | Geographic Concentration Risk [Member]
Percent of consolidated net revenue	4.10%	11.90%
CHINA
Net revenues	$ 2,860	$ 3,263
CHINA | Revenue Benchmark [Member] | Geographic Concentration Risk [Member]
Percent of consolidated net revenue	4.80%	5.30%	6.00%
JAPAN
Net revenues	$ 2,023	$ 2,450
JAPAN | Revenue Benchmark [Member] | Geographic Concentration Risk [Member]
Percent of consolidated net revenue	3.40%	4.00%
CANADA
Net revenues	$ 1,647	$ 1,878
CANADA | Revenue Benchmark [Member] | Geographic Concentration Risk [Member]
Percent of consolidated net revenue	2.80%	3.10%
INDIA
Net revenues	$ 1,616	$ 2,226
INDIA | Revenue Benchmark [Member] | Geographic Concentration Risk [Member]
Percent of consolidated net revenue	2.70%	3.60%
AUSTRALIA
Net revenues	$ 319	$ 323
AUSTRALIA | Revenue Benchmark [Member] | Geographic Concentration Risk [Member]
Percent of consolidated net revenue	0.50%	0.60%