Leases - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 31, 2022	Jul. 31, 2021	Jul. 31, 2022	Jul. 31, 2021
Leases [Line Items]
Operating lease expense	$ 3	$ 3	$ 7	$ 7
Maximum
Leases [Line Items]
Operating leases, options to extend leases term	9 years		9 years
Finance leases, options to extend leases term	9 years		9 years