Income Taxes - Schedule of Differences between the U.S. statutory rate and the aggregate income tax provision (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2026	Jan. 31, 2025	Jan. 31, 2024
Income Tax Disclosure [Abstract]
Income tax provision(benefit) at U.S. Federal statutory rate	$ 337	$ 291	$ 239
State income tax benefit, net of the U.S. federal benefit	13	10	24
Foreign income taxed at rate different from the U.S. statutory rate		(34)	(12)
Valuation allowance adjustment	19	(15)	1
Tax effect of nondeductible stock-based compensation	65	25	38
Stock compensation windfall/shortfall		(28)	2
Research and development tax credit benefit	(30)	(18)	(17)
Closure of income tax audits and changes in uncertain tax positions		52	13
Tax effect of officer compensation in excess of $1M		9	8
Nondeductible expenses	13	5	2
Cross-board tax effect		(30)	(39)
Acquisition-related integration		1	(29)
Other		4	0
Income tax provision	$ 479	$ 272	$ 230