Note 8 - Geographic Information and Major Customer Data - Major Customers Data As Percentage of Total Revenues (Details) - Revenue from Contract with Customer Benchmark [Member] - Customer Concentration Risk [Member]	3 Months Ended
	Mar. 31, 2020		Mar. 31, 2019
Customer A [Member]
Percentage of total revenues	16.00%		21.00%
Customer B [Member]
Percentage of total revenues		[1]	12.00%
Customer C [Member]
Percentage of total revenues		[1]	12.00%
Customer D [Member]
Percentage of total revenues		[1]	10.00%

[1] Less than 10%