Deferred Compensation (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 31, 2024	Jul. 31, 2023	Jul. 31, 2024	Jul. 31, 2023	Jan. 31, 2024
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Costs to obtain a contract	$ 240,000,000		$ 240,000,000		$ 210,000,000
Amortization of costs to obtain a contract with a customer	44,000,000	$ 33,000,000	85,000,000	$ 63,000,000
Impairment losses	0	$ 0	0	$ 0
Prepaid expenses and other current assets
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Costs to obtain a contract	133,000,000		133,000,000
Long-term other assets
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Costs to obtain a contract	107,000,000		107,000,000
Rabbi Trust
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Deferred compensation liability	116,000,000		116,000,000		100,000,000
Deferred compensation liability, current	12,000,000		12,000,000		10,000,000
Deferred compensation liability, non-current	$ 104,000,000		$ 104,000,000		$ 90,000,000