Segment, Customer Concentration and Geographical Information - Company's Customers that Represent 10% or More of Company's Net Revenues (Detail) - Revenues [Member] - Customer Concentration Risk [Member]	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Wireless [Member] | Sprint and Affiliates [Member]
Revenue, Major Customer [Line Items]
Customer concentrating on 10% or more of net revenue	86.00%	59.00%	81.00%	60.00%
Graphics [Member] | FastSpring [Member]
Revenue, Major Customer [Line Items]
Customer concentrating on 10% or more of net revenue	3.00%	13.00%	5.00%	14.00%