Operating Segment Information (Narrative) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
AT & T [Member]
Percentage of sales revenue from major customer	19.00%	14.00%	14.00%	14.00%
Verizon [Member]
Percentage of sales revenue from major customer	11.00%	12.00%	15.00%
Brazil [Member]
Percentage of sales revenue from major geographical region	12.00%		10.00%
India [Member]
Percentage of sales revenue from major geographical region		14.00%	14.00%	12.00%