Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue:
Online game	$ 665,593	$ 547,291	$ 590,755
Advertising and other	195,797	194,129	173,962
Total revenue	861,390	741,420	764,717
Costs and expenses:
Cost of revenue	258,971	238,546	235,985
Research and development	256,012	320,300	361,931
Sales and marketing	212,030	183,637	169,573
General and administrative	108,653	92,509	143,284
Impairment of intangible assets		20,677
Total costs and expenses	835,666	855,669	910,773
Income (loss) from operations	25,724	(114,249)	(146,056)
Interest income	5,309	3,057	2,568
Other income (expense), net	6,550	6,461	13,306
Income (loss) before income taxes	37,583	(104,731)	(130,182)
Provision for (benefit from) income taxes	10,944	3,442	(8,672)
Net income (loss)	$ 26,639	$ (108,173)	$ (121,510)
Net income (loss) per share attributable to common stockholders:
Basic	$ 0.03	$ (0.12)	$ (0.13)
Diluted	$ 0.03	$ (0.12)	$ (0.13)
Weighted average common shares used to compute net income (loss) per share attributable to common stockholders:
Basic	869,067	878,827	913,511
Diluted	897,165	878,827	913,511