Note 16 - Segment Information (Details Textual)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Number of Reportable Segments	3
Product Concentration Risk [Member] | Sales Revenue, Segment [Member] | Home [Member] | Telephony [Member]
Concentration Risk, Percentage	54.00%	57.00%	72.00%
Product Concentration Risk [Member] | Sales Revenue, Segment [Member] | Home [Member] | Gateway [Member]
Concentration Risk, Percentage	9.00%	8.00%	10.00%
Product Concentration Risk [Member] | Sales Revenue, Segment [Member] | Office [Member] | VoIP [Member]
Concentration Risk, Percentage	28.00%	19.00%	15.00%
Product Concentration Risk [Member] | Sales Revenue, Segment [Member] | Mobile [Member]
Concentration Risk, Percentage	4.00%	12.00%	0.00%