Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue:
Total revenue	$ 233,243	$ 224,595	$ 658,520	$ 628,110
Costs and expenses:
Cost of revenue	78,592	65,907	221,816	194,956
Research and development	71,124	60,966	199,340	194,783
Sales and marketing	55,613	53,944	159,346	151,765
General and administrative	23,144	23,826	71,977	69,942
Total costs and expenses	228,473	204,643	652,479	611,446
Income (loss) from operations	4,770	19,952	6,041	16,664
Interest income	1,421	1,502	5,031	3,548
Other income (expense), net	4,014	1,181	10,020	4,231
Income (loss) before income taxes	10,205	22,635	21,092	24,443
Provision for (benefit from) income taxes	5	4,544	6,194	10,733
Net income (loss)	$ 10,200	$ 18,091	$ 14,898	$ 13,710
Net income (loss) per share attributable to common stockholders:
Basic	$ 0.01	$ 0.02	$ 0.02	$ 0.02
Diluted	$ 0.01	$ 0.02	$ 0.02	$ 0.02
Weighted average common shares used to compute net income (loss) per share attributable to common stockholders:
Basic	860,988	867,377	863,062	868,707
Diluted	887,228	893,684	890,146	895,207
Online Game [Member]
Revenue:
Total revenue	$ 167,716	$ 175,253	$ 493,949	$ 492,479
Advertising and Other [Member]
Revenue:
Total revenue	$ 65,527	$ 49,342	$ 164,571	$ 135,631