Net Income Per Share - Reconciliation of Denominator Used in Calculation of Basic and Diluted Earnings Per Share (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2020
Numerator:
Net income	$ 1,444	$ 4,072	$ 126
Denominator:
Weighted-average shares outstanding for basic earnings per share (in shares)	955	908	829
Dilutive effect of employee stock awards (in shares)	19	22	21
Adjusted weighted-average shares outstanding and assumed conversions for diluted earnings per share (in shares)	974	930	850