Note 5 - Accounts Receivable and Customer Concentrations (Tables)

12 Months Ended

Dec. 31, 2018

Notes Tables

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

	Revenue						Accounts Receivable
	2018			2017			2018			2017
Customer A		4.9	%		9.3	%		4.8	%		15.2	%
Customer B		13.2	%		26.6	%		13.9	%		25.8	%
Customer C		7.2	%		11.9	%		4.0	%		9.0	%
Customer D		3.8	%		11.3	%		0.1	%		7.6	%
Customer E		40.1	%		--	%		52.6	%		--	%