Segment Information - Accounts Receivable (Details)	3 Months Ended		9 Months Ended			12 Months Ended	9 Months Ended
	Sep. 30, 2013 Nokia Siemens Networks [Member]	Sep. 30, 2012 Nokia Siemens Networks [Member]	Sep. 30, 2013 Nokia Siemens Networks [Member]	Sep. 30, 2012 Nokia Siemens Networks [Member]	Sep. 30, 2013 Nokia Siemens Networks [Member] Accounts Receivable [Member]	Dec. 31, 2012 Nokia Siemens Networks [Member] Accounts Receivable [Member]	Sep. 30, 2013 Arbor Networks [Member] Accounts Receivable [Member]
Concentration Risk [Line Items]
Entity-Wide Revenue, Major Customer, Percentage	20.70%	23.70%	19.50%	23.10%	27.60%	24.70%	10.10%