Costs to Obtain a Contract with a Customer (Details) - USD ($)	3 Months Ended
	Apr. 30, 2026	Apr. 30, 2025	Jan. 31, 2026
Capitalized Contract Cost [Line Items]
Costs to obtain a contract	$ 820,000,000		$ 913,000,000
Current liability	382,000,000		$ 550,000,000
Amortization of costs to obtain a contract with a customer	172,000,000	$ 96,000,000
Impairment losses	0	0
Revision of Prior Period, Reclassification, Adjustment
Capitalized Contract Cost [Line Items]
Amortization of costs to obtain a contract with a customer	$ 172,000,000	$ 96,000,000