Segment, Customer Concentration and Geographical Information - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2014 Location	Sep. 30, 2013 Location	Sep. 30, 2014 Business_Unit Location Customer	Sep. 30, 2013 Customer Location
Revenue, Major Customer [Line Items]
Number of primary business units			2
Number of customers that contribute more than 10% of revenue			3	3
Number of geographic locations	3	3	3	3
Credit Concentration Risk [Member] | Accounts receivable [Member] | Sprint, Verizon Wireless and Fast Spring [Member]
Revenue, Major Customer [Line Items]
Percentage of concentration			94.00%	88.00%