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
	Mar. 31, 2018	Mar. 31, 2017
Wireless [Member] | Sprint and Affiliates [Member]
Revenue, Major Customer [Line Items]
Customer concentrating on 10% or more of net revenue	75.30%	61.80%
Graphics [Member] | FastSpring [Member]
Revenue, Major Customer [Line Items]
Customer concentrating on 10% or more of net revenue	10.00%	13.90%