Leases - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Apr. 30, 2021	Apr. 30, 2020
Lessee Lease Description [Line Items]
Operating lease expense	$ 0.8	$ 0.7
Weighted-average remaining lease term – operating leases	4 years 2 months 12 days
Weighted-average discount rate – operating leases	3.82%
Extended Office Lease [Member]
Lessee Lease Description [Line Items]
Increase to operating lease right-of-use assets	$ 1.7
Increase to operating lease liabilities	$ 1.7
Shanghai [Member] | Extended Office Lease [Member]
Lessee Lease Description [Line Items]
Inception date	Dec. 01, 2021
Expiration date	Nov. 30, 2024
Lease term	3 years
Shanghai [Member] | Additional Office Space [Member]
Lessee Lease Description [Line Items]
Expiration date	Nov. 30, 2024
Lease term	40 months
Commencement date	Aug. 01, 2021
Future undiscounted cash payments	$ 1.7