Revenue - Schedule Of Deferred contract acquisition costs (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Jan. 31, 2020
Capitalized Contract Cost [Roll Forward]
Beginning balance, January 31, 2020			$ 3,314
Additions to deferred contract acquisition costs			1,901
Amortization of deferred contract acquisition costs	$ (505)	$ (491)	(2,280)	$ (1,465)
Ending balance, October 31, 2020	2,935		2,935
Deferred contract acquisition costs, current (to be amortized in next 12 months)					$ 1,708	$ 1,720
Deferred contract acquisition costs, non-current					1,227	1,594
Total deferred contract acquisition costs	$ 2,935		$ 2,935		$ 2,935	$ 3,314