Composition of certain financial statement captions - Schedule of Finite Lived Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2021	Jan. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangibles	$ 3,250	$ 3,250
Less accumulated amortization	(653)	(525)
Net carrying value	$ 2,597	2,725
Acquired technology
Finite-Lived Intangible Assets [Line Items]
Useful life (years)	5 years
Finite-lived intangibles	$ 1,410	1,410
Customer relationship
Finite-Lived Intangible Assets [Line Items]
Useful life (years)	10 years
Finite-lived intangibles	$ 1,840	$ 1,840