Net Income Per Share - Computation of Net Income Per Share Amounts (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Jul. 31, 2023	Apr. 30, 2023	Jul. 31, 2022	Apr. 30, 2022	Jul. 31, 2023	Jul. 31, 2022
Numerator:
Net income	$ 222	$ 161	$ 186	$ 146	$ 383	$ 332
Denominator:
Denominator for basic net income per share—weighted average shares (in shares)	214		217		214	217
Effect of dilutive securities (in shares)	1		1		2	1
Denominator for dilutive net income per share (in shares)	215		218		216	218
Basic net income per share (in usd per share)	$ 1.04		$ 0.86		$ 1.79	$ 1.53
Diluted net income per share (in usd per share)	$ 1.03		$ 0.85		$ 1.77	$ 1.52