Revenue from Contracts with Customers - Summary of Revenue Disaggregated by Platform (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation Of Revenue [Line Items]
Total revenue	$ 217,045	$ 209,231	$ 425,277	$ 403,515
Mobile Online Game [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	143,026	139,250	282,856	266,489
Web Online Game [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	21,654	24,495	43,377	50,737
Online Game [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	164,680	163,745	326,233	317,226
Mobile Advertising and Other [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	49,718	40,618	92,489	74,992
Web Advertising and Other [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	2,528	3,825	4,582	9,505
Other Advertising [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	119	1,043	1,973	1,792
Advertising and Other [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	$ 52,365	$ 45,486	$ 99,044	$ 86,289