Stockholders' Equity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended				6 Months Ended
	Jul. 31, 2025	Apr. 30, 2025	Jul. 31, 2024	Apr. 30, 2024	Jul. 31, 2025	Jul. 31, 2024
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 2,617	$ 2,621	$ 2,161	$ 1,855	$ 2,621	$ 1,855
Common shares issued under stock plans	(47)	(73)	(38)	(62)
Stock-based compensation expense	194	233	170	151
Settlement of liability-classified restricted common shares				3	0	3
Net income	313	152	282	252	465	534
Other comprehensive income (loss)	(6)	37	14	(29)	31	(15)
Repurchase and retirement of common shares	(356)	(353)	(115)	(9)
Ending balance	$ 2,715	$ 2,617	$ 2,474	$ 2,161	$ 2,715	$ 2,474
Common Stock Repurchase Program
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock repurchased and retired (in shares)	1,200		471		2,500	504
Repurchased shares of its common stock on the open market, average repurchase price per share (in usd per share)	$ 297.59		$ 244.63		$ 282.39	$ 245.29
November 2022 Common Stock Repurchase Program
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amount remained available for repurchase under repurchase plans	$ 3,170		$ 4,620		$ 3,170	$ 4,620
November 2024 Common Stock Repurchase Program
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amount remained available for repurchase under repurchase plans	$ 5,000				$ 5,000
Common stock and additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)	214,000	214,000	215,000	214,000	214,000	214,000
Beginning balance	$ 4,324	$ 4,239	$ 3,894	$ 3,802	$ 4,239	$ 3,802
Common shares issued under stock plans (in shares)		1,000		1,000
Common shares issued under stock plans	(47)	$ (73)	(38)	$ (62)
Stock-based compensation expense	194	$ 233	170	151
Settlement of liability-classified restricted common shares				$ 3
Repurchase and retirement of common shares (in shares)		(1,000)		0
Repurchase and retirement of common shares	$ (15)	$ (75)	$ (17)	$ 0
Ending balance (in shares)	213,000	214,000	215,000	215,000	213,000	215,000
Ending balance	$ 4,456	$ 4,324	$ 4,009	$ 3,894	$ 4,456	$ 4,009
Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(248)	(285)	(263)	(234)	(285)	(234)
Other comprehensive income (loss)	(6)	37	14	(29)
Ending balance	(254)	(248)	(249)	(263)	(254)	(249)
Accumulated deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,459)	(1,333)	(1,470)	(1,713)	(1,333)	(1,713)
Net income	313	152	282	252
Repurchase and retirement of common shares	(341)	(278)	(98)	(9)
Ending balance	$ (1,487)	$ (1,459)	$ (1,286)	$ (1,470)	$ (1,487)	$ (1,286)