Revenue - Schedule Of Deferred contract acquisition costs (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2020	Jan. 31, 2020
Capitalized Contract Cost [Roll Forward]
Beginning balance	$ 3,314
Additions to deferred contract acquisition costs	714
Amortization of deferred contract acquisition costs	(525)	$ (484)
Ending balance	3,503
Deferred contract acquisition costs, current (to be amortized in next 12 months)			$ 1,788	$ 1,720
Deferred contract acquisition costs, non current			1,715	1,594
Total deferred contract acquisition costs	$ 3,503		$ 3,503	$ 3,314