Note 6 - Concentration of Revenue (Tables)

6 Months Ended

Jun. 30, 2017

Notes Tables

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

	Three Months Ended June 30,						Six Months Ended June 30,
	201 7			2016			2017			2016
Customer A		6.1	%		14.7	%		8.1	%		19.0	%
Customer B		8.9	%		3.0	%		10.6	%		2.5	%
Customer C		9.1	%		15.5	%		11.3	%		12.4	%
Customer D		46.6	%		14.9	%		35.1	%		14.8	%
Customer E		5.8	%		10.6	%		7.0	%		9.5	%