CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Total revenues	$ 1,330,576	$ 1,088,743	$ 863,893
Cost of revenues	464,125	388,573	300,450
Gross profit	866,451	700,170	563,443
Operating expenses:
Research and development	414,875	360,344	365,878
Sales and marketing	162,726	148,553	150,457
General and administrative	79,473	68,870	52,170
Restructuring and impairment charges	1,457	10,329	12,019
Total operating expenses	658,531	588,096	580,524
Income (loss) from operations	207,920	112,074	(17,081)
Interest and other, net	16,009	137	(4,822)
Income (loss) before taxes on income	223,929	112,211	(21,903)
Provision for (benefit from) taxes on income	18,834	(22,047)	(2,478)
Net income (loss)	$ 205,095	$ 134,258	$ (19,425)
Net income (loss) per share - basic (in USD per share)	$ 3.73	$ 2.54	$ (0.39)
Net income (loss) per share - diluted (in USD per share)	$ 3.62	$ 2.46	$ (0.39)
Shares used in computing net income (loss) per share:
Basic (in shares)	54,946	52,863	50,310
Diluted (in shares)	56,662	54,646	50,310