Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue:
Total revenue	$ 306,500	$ 217,045	$ 571,903	$ 425,277
Costs and expenses:
Cost of revenue	126,872	74,182	248,515	143,224
Research and development	102,094	67,391	263,974	128,216
Sales and marketing	113,529	52,878	215,540	103,733
General and administrative	25,239	25,580	46,743	48,833
Total costs and expenses	367,734	220,031	774,772	424,006
Income (loss) from operations	(61,234)	(2,986)	(202,869)	1,271
Interest income	889	1,800	1,332	3,610
Interest expense	(2,167)	(9)	(3,430)	(14)
Other income (expense), net	3,877	2,614	7,252	6,020
Income (loss) before income taxes	(58,635)	1,419	(197,715)	10,887
Provision for (benefit from) income taxes	(2,805)	2,330	(13,057)	6,189
Net income (loss)	$ (55,830)	$ (911)	$ (184,658)	$ 4,698
Net income (loss) per share attributable to common stockholders:
Basic	$ (0.06)	$ 0.00	$ (0.20)	$ 0.01
Diluted	$ (0.06)	$ 0.00	$ (0.20)	$ 0.01
Weighted-average common shares used to compute net income (loss) per share attributable to common stockholders:
Basic	937,334	858,666	931,813	864,117
Diluted	937,334	858,666	931,813	890,285
Online Game [Member]
Revenue:
Total revenue	$ 240,708	$ 164,680	$ 440,872	$ 326,233
Advertising and Other [Member]
Revenue:
Total revenue	$ 65,792	$ 52,365	$ 131,031	$ 99,044