v3.21.1

Summary of significant accounting policies (Detail)		1 Months Ended	3 Months Ended	12 Months Ended
	Oct. 23, 2020 USD ($) $ / shares shares	Oct. 31, 2020 USD ($) $ / shares shares	Apr. 30, 2020	Jan. 31, 2021 USD ($) processors segment		Jan. 31, 2020 USD ($)		Jan. 31, 2019 USD ($)	Feb. 01, 2020 USD ($)
Accounting Policies [Line Items]
Number of third party payment processors | processors				1
Advertising expense				$ 558,000		$ 251,000		$ 134,000
Allowance for doubtful accounts				699,000		943,000
Asset impairment charges				$ 0		0		0
Number of operating segment | segment				1
Issuance of common stock, net of issuance costs (in shares) | shares	5,750,000	5,750,000
Issue price per share (in USD per share) | $ / shares	$ 32.00	$ 32.00
Net proceeds after discounts and offering expenses	$ 174,510,000	$ 174,800,000		$ 174,800,000		130,781,000		$ 0
Lease right-of-use assets				2,654,000	[1]	$ 0	[1]		$ 2,741,000
Total operating lease liabilities				$ 2,986,000
Customer Concentration Risk | Accounts Receivable | One entity
Accounting Policies [Line Items]
Accounts receivable concentration percentage				10.00%
Topic 842
Accounting Policies [Line Items]
Lease right-of-use assets									2,741,000
Total operating lease liabilities									$ 2,928,000
Internal-use software
Accounting Policies [Line Items]
Estimated useful life (in years)			3 years
Minimum
Accounting Policies [Line Items]
Settlement period (in days)				1 day
Useful life (years)				3 years
Maximum
Accounting Policies [Line Items]
Settlement period (in days)				2 days
Useful life (years)				7 years
[1] Figures as of January 31, 2021 reflect the Company's February 1, 2020 adoption of Accounting Standards Codification No. 842, Leases (ASC 842). For additional details, see Note 3(ac), "Summary of significant accounting policies — Impact of recently adopted accounting pronouncements."

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