Purchase price paid by employees for common stock through an employee stock purchase plan.

No definition available.

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- Definition

Full Value Stock to Stock Options Ratio

+ References

No definition available.

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- Definition

The maximum value that an employee can purchase of shares through the ESPP in an annual period.

+ References

No definition available.

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- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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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.

+ References

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- Definition

Amount of cash outflow to satisfy grantee's tax withholding obligation for award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
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-Subparagraph (a)
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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.

+ References

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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.

+ References

No definition available.

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- Definition

The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

+ References

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- Definition

Number of additional shares authorized for issuance under share-based payment arrangement.

+ References

No definition available.

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- Definition

Number of shares authorized for issuance under share-based payment arrangement.

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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.

+ References

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- Definition

Purchase price of common stock expressed as a percentage of its fair value.

+ References

No definition available.

+ Details

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- Definition

Number of shares used to settle grantee's tax withholding obligation for award under share-based payment arrangement.

+ References

No definition available.

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- Definition

Number of shares issued during the period as a result of an employee stock purchase plan.

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- Definition

Number of shares that have been repurchased during the period and are being held in treasury.

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- Definition

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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Employee Stock Plans - Additional Information (Detail)	3 Months Ended
Employee Stock Plans - Additional Information (Detail)	Jul. 31, 2019 USD ($) $ / shares shares	Jul. 31, 2018 USD ($) $ / shares shares	Apr. 30, 2019 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payments of tax withholdings on restricted stock \| $	$ 8,591,000	$ 13,054,000
Shares repurchased during the period, value \| $	$ 21,329,000	$ 13,054,000
Treasury Stock, Common
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares repurchased during the period	324,100	0
Shares repurchased during the period, value \| $	$ 12,700,000
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares reserved for issuance	3,000,000.0
Authorized payroll deductions	15.00%
Fair market price of common stock	85.00%
Authorized payroll deductions, value \| $	$ 25,000
Shares available for future issuance	800,000
Employees stock purchased	126,604	75,106
Employees stock purchased, price per share \| $ / shares	$ 34.06	$ 52.64
Time Based Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Market Based Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Shares outstanding	500,000
Total unrecognized compensation cost related to non-vested awards \| $	$ 17,900,000
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding	1,409,000		1,460,000
Total unrecognized compensation cost related to non-vested awards \| $	$ 51,200,000
Expected cost recognized over weighted-average period	2 years 9 months 18 days
Shares repurchased during the period to pay for taxes	221,654	199,795
Payments of tax withholdings on restricted stock \| $	$ 8,600,000	$ 13,100,000
Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock incentive plan, additional number of shares	5,500,000
Maximum number of shares reserved for issuance	11,200,000
Issuance of full-value stock awards limitation, required ratio to stock options	2.3