Significant Customers (Details Textual) - customer	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Significant Customers (Textual) [Abstract]
Numbers of customers	2	2	2	2
Revenues attributable to sales [Line Items]
Percentage of net revenue	35.90%	35.50%	38.20%	35.10%
Avnet
Revenues attributable to sales [Line Items]
Percentage of net revenue	27.70%	29.40%	27.60%	27.40%
Engenuity
Revenues attributable to sales [Line Items]
Percentage of net revenue	8.20%	6.10%	10.60%	7.70%