Stockholders' Equity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended						9 Months Ended
	Oct. 31, 2025	Jul. 31, 2025	Apr. 30, 2025	Oct. 31, 2024	Jul. 31, 2024	Apr. 30, 2024	Oct. 31, 2025	Oct. 31, 2024
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 2,715	$ 2,617	$ 2,621	$ 2,474	$ 2,161	$ 1,855	$ 2,621	$ 1,855
Common shares issued under stock plans	14	(47)	(73)	13	(38)	(62)
Stock-based compensation expense	191	194	233	184	170	151
Settlement of liability-classified restricted common shares						3	0	3
Net income	343	313	152	275	282	252	808	809
Other comprehensive income (loss)	(9)	(6)	37	(11)	14	(29)	22	(26)
Repurchase and retirement of common shares	(361)	(356)	(353)	(319)	(115)	(9)
Ending balance	$ 2,893	$ 2,715	$ 2,617	$ 2,616	$ 2,474	$ 2,161	$ 2,893	$ 2,616
Common Stock Repurchase Program
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock repurchased and retired (in shares)	1,000			1,200			3,000	1,700
Repurchased shares of its common stock on the open market, average repurchase price per share (in usd per share)	$ 306.35			$ 269.30			$ 290.04	$ 262.15
November 2022 Common Stock Repurchase Program
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Amount remained available for repurchase under repurchase plans	$ 2,810			$ 4,300			$ 2,810	$ 4,300
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)	213,000	214,000	214,000	215,000	215,000	214,000	214,000	214,000
Beginning balance	$ 4,456	$ 4,324	$ 4,239	$ 4,009	$ 3,894	$ 3,802	$ 4,239	$ 3,802
Common shares issued under stock plans (in shares)	0		1,000	1,000		1,000
Common shares issued under stock plans	$ 14	(47)	$ (73)	$ 13	(38)	$ (62)
Stock-based compensation expense	$ 191	$ 194	$ 233	$ 184	170	151
Settlement of liability-classified restricted common shares						$ 3
Repurchase and retirement of common shares (in shares)	(1,000)	(1,000)	(1,000)	(1,000)		0
Repurchase and retirement of common shares	$ (73)	$ (15)	$ (75)	$ (106)	$ (17)	$ 0
Ending balance (in shares)	212,000	213,000	214,000	215,000	215,000	215,000	212,000	215,000
Ending balance	$ 4,588	$ 4,456	$ 4,324	$ 4,100	$ 4,009	$ 3,894	$ 4,588	$ 4,100
Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(254)	(248)	(285)	(249)	(263)	(234)	(285)	(234)
Other comprehensive income (loss)	(9)	(6)	37	(11)	14	(29)
Ending balance	(263)	(254)	(248)	(260)	(249)	(263)	(263)	(260)
Accumulated deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,487)	(1,459)	(1,333)	(1,286)	(1,470)	(1,713)	(1,333)	(1,713)
Net income	343	313	152	275	282	252
Repurchase and retirement of common shares	(288)	(341)	(278)	(213)	(98)	(9)
Ending balance	$ (1,432)	$ (1,487)	$ (1,459)	$ (1,224)	$ (1,286)	$ (1,470)	$ (1,432)	$ (1,224)