Operating Segment Information (Narrative) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
AT & T [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of sales revenue from major customer	16.00%	22.00%	15.00%	17.00%
Carso Global Telecom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of sales revenue from major customer	12.00%
Verizon [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of sales revenue from major customer	11.00%	10.00%	13.00%
Brazil [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of sales revenue from major geographical region	15.00%		12.00%
India [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of sales revenue from major geographical region		14.00%	10.00%	12.00%