Net Income Per Share - Computation of Net Income Per Share Amounts (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Numerator:
Net income	$ 161	$ 146
Denominator:
Denominator for basic net income per share—weighted average shares (in shares)	215	217
Effect of dilutive securities (in shares)	1	2
Denominator for dilutive net income per share (in shares)	216	219
Basic net income per share (in dollars per share)	$ 0.75	$ 0.67
Diluted net income per share (in dollars per share)	$ 0.75	$ 0.67