Income Tax (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 31, 2022	Jul. 31, 2021	Jul. 31, 2022	Jul. 31, 2021
Tax Credit Carryforward [Line Items]
Provision for income tax expense (benefit)	$ 46	$ 24	$ 95	$ (1)
(Loss) income before income taxes	232	$ 139	427	$ 270
Unrecognized tax benefits	207		207
Unrecognized tax benefits that would reduce the valuation allowance if recognized	34		34
Decrease in unrecognized tax benefits	8
SEC Schedule, 12-09, Valuation Allowance, Tax Credit Carryforward
Tax Credit Carryforward [Line Items]
Amount of gross unrecognized tax benefits that would impact the effective tax rate, if recognized	$ 173		$ 173