Stockholders' Equity - Narrative (Details)	12 Months Ended
	Jan. 31, 2026 USD ($) plan $ / shares shares	Jan. 31, 2025 USD ($) $ / shares shares	Jan. 31, 2024 USD ($) $ / shares shares	Feb. 01, 2026 shares	May 31, 2025 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock-based compensation plans | plan	2
Shares granted in period (in shares) | shares	0	0	0
Unrecognized compensation cost, options | $	$ 0
Intrinsic value of options exercised | $	4,900,000	$ 73,600,000	$ 23,600,000
Employee stock purchase plan, compensation expense | $	$ 622,321,000	$ 610,335,000	$ 616,847,000
Reserved for future issuance (in shares) | shares	83,521,000	78,557,000
Stock repurchase program, authorized amount | $					$ 2,500,000,000
2003 Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards outstanding (in shares) | shares	0
2018 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual increase in shares reserved, percentage of total shares	5.00%
2018 Plan | Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in shares reserved for issuance (in shares) | shares				9,900,000
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards outstanding (in shares) | shares	23,792,000	27,268,000
Weighted average grant date fair value of RSUs (in usd per share) | $ / shares	$ 83.61	$ 60.89	$ 54.15
Grant date fair value | $	$ 632,400,000	$ 627,900,000	$ 631,800,000
Unrecognized compensation cost, RSUs | $	$ 1,100,000,000
Unrecognized compensation cost, remaining weighted-average period for recognition	2 years 3 months 18 days
Reserved for future issuance (in shares) | shares	23,792,000	27,268,000
RSUs | Market Based and Performance Based Vesting Conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value | $	$ 170,500,000
Performance vesting percentage	100.00%
RSUs | 2018 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
RSUs | 2018 Plan | Alternate vesting option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
Annual vesting percentage	25.00%
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual increase in shares reserved, percentage of total shares	1.00%
Increase in shares reserved for issuance (in shares) | shares	3,800,000
Employee contribution, maximum percentage of earnings	15.00%
Percent of purchase price of fair value of common stock	85.00%
ESPP offering period	6 months
Employee stock purchase plan, compensation expense | $	$ 17,700,000	$ 13,400,000	$ 16,000,000.0
Reserved for future issuance (in shares) | shares	13,115,000	11,819,000