Significant Customers (Details Textual) - customer	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenues attributable to sales [Line Items]
Numbers of customers	2	2	2	2
Total	38.90%	31.20%	37.00%	37.00%
Avnet [Member]
Revenues attributable to sales [Line Items]
Total	28.20%	27.70%	27.70%	27.60%
Enel [Member]
Revenues attributable to sales [Line Items]
Total	10.70%	3.50%	9.30%	9.40%