Stockholders' Equity - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Jan. 31, 2022	Jan. 31, 2021
Number of shares
Options outstanding, beginning balance (in shares)	12,761,289
Options granted (in shares)	1,155,396
Options exercised (in shares)	(1,476,898)
Options forfeited/cancelled (in shares)	(349,265)
Options outstanding, ending balance (in shares)	12,090,522	12,761,289
Options vested and exercisable (in shares)	7,203,834
Options vested and exercisable and expected to vest thereafter (in shares)	12,090,522
Weighted average exercise price
Options outstanding, beginning balance (in usd per share)	$ 57.48
Options granted (in usd per share)	277.06
Options exercised (in usd per share)	34.90
Options forfeited/cancelled (in usd per share)	172.64
Options outstanding, ending balance (in usd per share)	77.89	$ 57.48
Options vested and exercisable (in usd per share)	32.35
Options vested and exercisable and expected to vest thereafter (in usd per share)	$ 77.89
Weighted average remaining contractual term (in years), options outstanding	4 years 7 months 6 days	5 years
Weighted average remaining contractual term (in years), options vested and exercisable	2 years 9 months 18 days
Weighted average remaining contractual term (in years), options vested and exercisable and expected to vest thereafter	4 years 7 months 6 days
Aggregate intrinsic value (in millions)
Options outstanding	$ 1,964	$ 2,794
Options vested and exercisable	1,472
Options vested and exercisable and expected to vest thereafter	$ 1,964