Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenue:
Total revenue	$ 217,045	$ 209,231	$ 425,277	$ 403,515
Costs and expenses:
Cost of revenue	74,182	64,172	143,224	129,049
Research and development	67,391	64,615	128,216	133,817
Sales and marketing	52,878	51,201	103,733	97,821
General and administrative	25,580	23,551	48,833	46,116
Total costs and expenses	220,031	203,539	424,006	406,803
Income (loss) from operations	(2,986)	5,692	1,271	(3,288)
Interest income	1,800	1,109	3,610	2,046
Other income (expense), net	2,605	1,614	6,006	3,050
Income (loss) before income taxes	1,419	8,415	10,887	1,808
Provision for (benefit from) income taxes	2,330	3,322	6,189	6,189
Net income (loss)	$ (911)	$ 5,093	$ 4,698	$ (4,381)
Net income (loss) per share attributable to common stockholders:
Basic	$ 0.00	$ 0.01	$ 0.01	$ (0.01)
Diluted	$ 0.00	$ 0.01	$ 0.01	$ (0.01)
Weighted average common shares used to compute net income (loss) per share attributable to common stockholders:
Basic	858,666	863,125	864,117	869,025
Diluted	858,666	887,991	890,285	869,025
Online Game [Member]
Revenue:
Total revenue	$ 164,680	$ 163,745	$ 326,233	$ 317,226
Advertising and Other [Member]
Revenue:
Total revenue	$ 52,365	$ 45,486	$ 99,044	$ 86,289