Revenue - Schedule Of Rollforward of contract assets and contract liabilities (Detail) $ in Thousands	9 Months Ended
	Oct. 31, 2020 USD ($)
Contract With Customer Asset [Roll Forward]
Beginning balance - Contract assets (unbilled accounts receivable)	$ 676
Amount transferred to receivables from beginning balance of contract assets	(676)
Contract asset additions, net of reclassification to receivables	2,344
Ending balance - Contract assets (unbilled accounts receivable)	2,344
Contract With Customer Liability [Roll Forward]
Beginning balance - Contract liabilities (deferred revenue)	5,401
Revenue recognized that was included in deferred revenue at the beginning of the period	(5,004)
Revenue recognized that was not included in deferred revenue at the beginning of the period	(1,168)
Increases due to invoicing prior to satisfaction of performance obligations	7,394
Ending balance - Contract liabilities (deferred revenue)	$ 6,623