Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2021	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 882,485	$ 777,196	$ 663,520	$ 328,167	$ 188,251	$ 166,593	$ 145,826	$ 121,988	$ 2,651,368	$ 622,658	$ 330,517
Gross profit	615,201	518,469	471,249	224,460	155,704	135,748	117,926	97,884	1,829,379	507,262	269,516
Income (loss) from operations	256,117	192,242	188,104	23,385	10,553	(1,679)	2,265	1,557	659,848	12,696	6,167
Net income attributable to common stockholders	$ 260,393	$ 198,440	$ 185,742	$ 27,036	$ 15,313	$ 2,207	$ 5,521	$ 198	$ 671,527	$ 21,750	$ 0
Net income per share attributable to common stockholders:
Basic (in dollars per share)	$ 0.91	$ 0.70	$ 0.66	$ 0.10	$ 0.06	$ 0.01	$ 0.02	$ 0.00	$ 2.37	$ 0.09	$ 0.00
Diluted (in dollars per share)	$ 0.87	$ 0.66	$ 0.63	$ 0.09	$ 0.05	$ 0.01	$ 0.02	$ 0.00	$ 2.25	$ 0.09	$ 0.00