v3.21.1

Equity-based compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019	Jun. 30, 2019	Jan. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			0	1,230,382
Intrinsic value			$ 33,575	$ 13,960	$ 1,355
Unrecognized compensation cost to stock option	$ 3,972		$ 3,972
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term			10 years
Vesting term			4 years
Percentage of vest option			25.00%
Stock-based compensation expense			$ 2,703	$ 2,780	$ 1,447
Weighted average term for recognition (in years)			1 year 9 months 25 days
Incremental expense associated with the modification of stock options			$ 385
Weighted average fair market value of grants (in USD per share)				$ 4.99	$ 3.47
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant (in shares)	855,873		855,873
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term			7 years
Vesting term			4 years
Stock-based compensation expense			$ 10,693	$ 3,356
Weighted average term for recognition (in years)			3 years 3 months 18 days
Shares granted (in shares)			972,271	1,493,678	0
Unrecognized compensation costs	$ 48,588		$ 48,588
Shares available to vest (in shares)	2,053,038	1,447,418	2,053,038	1,447,418	20,164
Restricted Stock Units (RSUs) | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)			0
Restricted Stock Units (RSUs) | Vital Score
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			$ 33	$ 40
Unrecognized compensation costs	$ 58		$ 58
Weighted average fair market value of grants (in USD per share)			$ 32.78	$ 21.31
Restricted Stock Units (RSUs) | Share-based Payment Arrangement, Year 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of vest option			10.00%
Restricted Stock Units (RSUs) | Share-based Payment Arrangement, Year 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of vest option			20.00%
Restricted Stock Units (RSUs) | Share-based Payment Arrangement, Year 3
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of vest option			30.00%
Restricted Stock Units (RSUs) | Share-based Payment Arrangement, Year 4
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of vest option			40.00%
Performance based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of vest option	100.00%
Stock-based compensation expense			$ 93
Weighted average term for recognition (in years)			3 years
Shares granted (in shares)		70,806
Unrecognized compensation costs	$ 5,882		$ 5,882
Weighted average fair market value of grants (in USD per share)			$ 84.38
Shares available to vest (in shares)		141,612		141,612
Performance based restricted stock units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of vest option	0.00%
Performance based restricted stock units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of vest option	200.00%
2018 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for issuance (in shares)							3,048,490
2019 Stock Option And Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserve for future issuance (in shares)						2,139,683
Percentage increase in shares reserved for future issuance			5.00%
Shares available for future grant (in shares)	2,256,810		2,256,810
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant (in shares)	855,873		855,873

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