Number of equity-based compensation plans.

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- Definition

Number of legacy plans.

+ References

No definition available.

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- Definition

Share-based compensation arrangement by share-based payment award, recurring grants vesting period.

+ References

No definition available.

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- Definition

Aggregate number of common shares reserved for future issuance.

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-Topic 210
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- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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- Definition

Amount of cost to be recognized for option under share-based payment arrangement.

+ References

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- Definition

Amount of cash inflow from exercise of option under share-based payment arrangement.

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- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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- Definition

Date the equity-based award expires, in CCYY-MM-DD format.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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- Definition

Percentage of vesting of award under share-based payment arrangement.

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- Definition

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Stock-Based Compensation - Additional Information (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Apr. 30, 2020 USD ($) Plan $ / shares shares	Apr. 30, 2019 USD ($) $ / shares	Apr. 30, 2018 USD ($) $ / shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of equity-based compensation plans \| Plan	3
Number of legacy plans \| Plan	2
Weighted-average grant date fair value of stock options granted \| $ / shares	$ 15.76	$ 9.62	$ 4.87
Total intrinsic value of stock options exercised \| $	$ 431,000	$ 950,000	$ 131,000
Total cash received as a result of employee stock option exercises \| $	216,000	$ 242,000	$ 36,000
Unrecognized compensation expense related to unvested awards \| $	$ 10,200
Unrecognized compensation expense related to unvested awards expected to be recognized over a weighted-average period	2 years 3 months 18 days
2017 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options, available for grant \| shares	942,122
Common stock reserved for issuance upon exercise or settlement of stock options or other awards \| shares	3,538,090
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grants vest percentage	25.00%
Recurring grants vesting period	4 years
Scheme termination period	10 years
Stock Options [Member] \| Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted, vesting period	1 year
Stock Options [Member] \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted, vesting period	3 years
Performance Based Restricted Stock Unit [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Performance-based restricted stock unit awards outstanding \| shares	45,000
Performance period expiration date	Jun. 30, 2022