Equity - Shares Outstanding (Details) - USD ($) $ / shares in Units, $ in Thousands					3 Months Ended			9 Months Ended
	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Oct. 31, 2020
Shares Available for Grant
Shares available for grant, beginning (in shares)					18,299,095	19,780,398	412,401	412,401
Shares authorized (in shares)					34,100,000		20,870,187
Shares ceased to be available for issuance (in shares)					(15,696,031)
Options granted (in shares)					(136,000)	(130,025)	(610,936)
Options forfeited (in shares)					543,634	1,216,461	1,354,238
Repurchase of unvested common stock (in shares)							40,000
Shares available for grant, ending (in shares)	34,342,175	18,299,095	19,780,398	412,401	34,342,175	18,299,095	19,780,398	34,342,175
Number of Options Outstanding
Shares outstanding, beginning (in shares)					72,228,820	75,214,178	80,903,200	80,903,200
Options granted (in shares)					136,000	130,025	610,936
Options exercised (in shares)					(2,186,819)	(1,898,922)	(4,945,720)
Options forfeited (in shares)					(543,634)	(1,216,461)	(1,354,238)
Shares outstanding, ending (in shares)	69,634,367	72,228,820	75,214,178	80,903,200	69,634,367	72,228,820	75,214,178	69,634,367
Weighted- Average Exercise Price
Shares outstanding, beginning balance (in dollars per share)					$ 6.70	$ 6.65	$ 6.21	$ 6.21
Granted (in dollars per share)					71.91	34.49	26.64
Exercises (in dollars per share)					4.74	5.19	2.23
Forfeited (in dollars per share)					7.52	8.68	5.47
Shares outstanding, ending balance (in dollars per share)	$ 6.88	$ 6.70	$ 6.65	$ 6.21	$ 6.88	$ 6.70	$ 6.65	$ 6.88
Weighted-average remaining contractual life	8 years	8 years 2 months 12 days	8 years 6 months	8 years 7 months 6 days
Aggregate Intrinsic Value (in thousands)
Aggregate intrinsic value	$ 16,930,996	$ 6,227,842	$ 2,416,057	$ 1,546,313	$ 16,930,996	$ 6,227,842	$ 2,416,057	$ 16,930,996
Vested and exercisable (in shares)	26,842,544				26,842,544			26,842,544
Vested and exercisable, weighted average share price (in dollars per share)	$ 4.86				$ 4.86			$ 4.86
Vested and exercisable, weighted average remaining contractual life	7 years 4 months 24 days
Vested and exercisable, intrinsic value	$ 6,580,709				$ 6,580,709			$ 6,580,709
RSUs
Shares Available for Grant
RSU's granted (in shares)					(2,841,823)	(2,587,289)	(2,295,492)
RSU's forfeited (in shares)					73,300	19,550	10,000