Segment, Customer Concentration and Geographical Information - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2015 Location	Sep. 30, 2014 Location	Sep. 30, 2015 Customer Location Business_Unit	Sep. 30, 2014 Customer Location
Revenue, Major Customer [Line Items]
Number of primary business units | Business_Unit			2
Number of customers that contribute more than 10% of revenue			2	2
Number of geographic locations | Location	3	3	3	3
Customer Concentration Risk [Member] | Accounts receivable [Member] | Sprint and Fast Spring [Member]
Revenue, Major Customer [Line Items]
Percentage of concentration			86.00%	87.00%