Stockholders' Equity (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Jul. 31, 2026	Apr. 30, 2026	Jul. 31, 2025	Apr. 30, 2025	Jul. 31, 2026	Jul. 31, 2025
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 3,189	$ 3,045	$ 2,617	$ 2,621	$ 3,045	$ 2,621
Common shares issued under stock plans	(30)	(55)	(47)	(73)
Stock-based compensation expense	188	159	194	233
Net income	492	491	313	152	983	465
Other comprehensive loss	1	(2)	(6)	37	(1)	31
Repurchase and retirement of common shares	(457)	(449)	(356)	(353)
Ending balance	$ 3,383	$ 3,189	$ 2,715	$ 2,617	$ 3,383	$ 2,715
Common Stock Repurchase Program
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock repurchased and retired (in shares)	2		1		4	2
Average repurchase price per share (in dollars per share)	$ 211.89		$ 297.59		$ 224.92	$ 282.39
November 2022 Common Stock Repurchase Program
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amount remained available for repurchase	$ 1,580		$ 3,170		$ 1,580	$ 3,170
November 2024 Common Stock Repurchase Program
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amount remained available for repurchase	$ 5,000		$ 5,000		$ 5,000	$ 5,000
Common stock and additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)	211	212	214	214	212	214
Beginning balance	$ 4,726	$ 4,709	$ 4,324	$ 4,239	$ 4,709	$ 4,239
Common shares issued under stock plans (in shares)		1		1
Common shares issued under stock plans	(30)	$ (55)	(47)	$ (73)
Stock-based compensation expense	$ 188	$ 159	$ 194	$ 233
Repurchase and retirement of common shares (in shares)	(2)	(2)	(1)	(1)
Repurchase and retirement of common shares	$ (38)	$ (87)	$ (15)	$ (75)
Ending balance (in shares)	209	211	213	214	209	213
Ending balance	$ 4,846	$ 4,726	$ 4,456	$ 4,324	$ 4,846	$ 4,456
Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(234)	(232)	(248)	(285)	(232)	(285)
Other comprehensive loss	1	(2)	(6)	37
Ending balance	(233)	(234)	(254)	(248)	(233)	(254)
Accumulated deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,303)	(1,432)	(1,459)	(1,333)	(1,432)	(1,333)
Net income	492	491	313	152
Repurchase and retirement of common shares	(419)	(362)	(341)	(278)
Ending balance	$ (1,230)	$ (1,303)	$ (1,487)	$ (1,459)	$ (1,230)	$ (1,487)