Significant Customers (Details Textual) - customer	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues attributable to sales [Line Items]
Numbers of customers	2	2	2	2
Total	37.90%	34.30%	37.40%	36.20%
Avnet [Member]
Revenues attributable to sales [Line Items]
Total	21.10%	26.90%	25.50%	27.40%
Enel [Member]
Revenues attributable to sales [Line Items]
Total	16.80%	7.40%	11.90%	8.80%