CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019
Income Statement [Abstract]
Revenue	$ 663,520	$ 145,826	$ 991,687	$ 267,814
Cost of revenue	192,271	27,900	295,978	52,004
Gross profit	471,249	117,926	695,709	215,810
Operating expenses:
Research and development	42,734	15,054	69,123	28,837
Sales and marketing	159,173	79,652	280,729	143,693
General and administrative	81,238	20,955	134,368	39,458
Total operating expenses	283,145	115,661	484,220	211,988
Income from operations	188,104	2,265	211,489	3,822
Interest income and other, net	2,081	4,492	7,871	5,465
Net income before provision for income taxes	190,185	6,757	219,360	9,287
Provision for income taxes	4,196	1,216	6,296	1,532
Net income	185,989	5,541	213,064	7,755
Undistributed earnings attributable to participating securities	(247)	(20)	(305)	(2,794)
Net income attributable to common stockholders	$ 185,742	$ 5,521	$ 212,759	$ 4,961
Net income per share attributable to common stockholders:
Basic (in dollars per share)	$ 0.66	$ 0.02	$ 0.76	$ 0.03
Diluted (in dollars per share)	$ 0.63	$ 0.02	$ 0.72	$ 0.02
Weighted-average shares used in computing net income per share attributable to common stockholders:
Basic (in shares)	282,850,805	271,813,141	281,394,901	192,130,510
Diluted (in shares)	297,162,309	292,185,665	296,408,229	215,774,619