Net Income Per Share - Computation of Net Income Per Share Amounts (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended						9 Months Ended
	Oct. 31, 2023	Jul. 31, 2023	Apr. 30, 2023	Oct. 31, 2022	Jul. 31, 2022	Apr. 30, 2022	Oct. 31, 2023	Oct. 31, 2022
Numerator:
Net income	$ 241	$ 222	$ 161	$ 198	$ 186	$ 146	$ 624	$ 530
Denominator:
Denominator for basic net income per share—weighted average shares (in shares)	214			216			214	217
Effect of dilutive securities (in shares)	2			1			2	1
Denominator for dilutive net income per share (in shares)	216			217			216	218
Basic net income per share (in usd per share)	$ 1.13			$ 0.92			$ 2.92	$ 2.44
Diluted net income per share (in usd per share)	$ 1.12			$ 0.91			$ 2.89	$ 2.43