Leases - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2021	Oct. 31, 2020	Oct. 31, 2021	Oct. 31, 2020
Lessee Lease Description [Line Items]
Operating lease expense	$ 0.9	$ 0.8	$ 2.5	$ 2.2
Weighted-average remaining lease term - operating leases	3 years 9 months 21 days		3 years 9 months 21 days
Weighted-average discount rate - operating leases	3.55%		3.55%
Extended Office Lease [Member]
Lessee Lease Description [Line Items]
Increase to operating lease right-of-use assets			$ 4.4
Increase to operating lease liabilities			$ 4.4
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		3 years
Shanghai [Member] | Additional Office Space [Member]
Lessee Lease Description [Line Items]
Expiration date			Nov. 30, 2024
Lease term	40 months		40 months
Commencement date			Aug. 01, 2021
Hong Kong [Member] | Extended Office Lease [Member]
Lessee Lease Description [Line Items]
Inception date			Dec. 01, 2021
Expiration date			Nov. 30, 2026
Lease term	5 years		5 years