Restructuring, other exit costs, and facility reductions - Schedule of Restructuring and Other Exist Costs (Details) $ in Millions	12 Months Ended
	Jan. 31, 2026 USD ($)
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 15
Restructuring Charges, Statement of Income or Comprehensive Income [Extensible Enumeration]	Restructuring, other exit costs, and facility reductions
Additions	$ 197
Payments	(112)
Ending Balance	100
Employee termination costs | January 2026 Plan
Restructuring Reserve [Roll Forward]
Beginning Balance	0
Additions	98
Payments	(1)
Ending Balance	97
Employee termination costs | 2026 Plan
Restructuring Reserve [Roll Forward]
Beginning Balance	15
Additions	93
Payments	(107)
Ending Balance	1
Other exit costs | January 2026 Plan
Restructuring Reserve [Roll Forward]
Beginning Balance	0
Additions	2
Payments	0
Ending Balance	2
Other exit costs | 2026 Plan
Restructuring Reserve [Roll Forward]
Beginning Balance	0
Additions	4
Payments	(4)
Ending Balance	$ 0