Common stock decreases in capital shares reserved for future issuance.

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

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

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

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

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

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

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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

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

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No definition available.

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

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

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

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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) - USD ($)		3 Months Ended						9 Months Ended
	Oct. 03, 2019	Jan. 31, 2021	Oct. 31, 2020	Jul. 31, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Jan. 31, 2021	Jan. 31, 2020	Apr. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payments of tax withholdings on restricted stock								$ 4,712,000	$ 8,862,000
Shares repurchased during the period, value		$ 7,779,000	$ 22,878,000	$ 4,442,000	$ 6,263,000	$ 49,325,000	$ 21,329,000
Treasury Stock, Common
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares repurchased during the period		220,000			154,100			973,451	1,787,292
Shares repurchased during the period, value		$ 7,600,000			$ 6,200,000			$ 30,400,000	$ 68,100,000
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future issuance		500,000						500,000
Authorized payroll deductions		15.00%						15.00%
Authorized payroll deductions, value								$ 25,000
Maximum number of shares reserved for issuance		3,000,000.0						3,000,000.0
Employees stock purchased		59,561			93,557			188,608	220,161
Employees stock purchased, price per share		$ 39.15			$ 36.04			$ 30.25	$ 34.90
ESPP \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair market price of common stock								85.00%
ESPP \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair market price of common stock								100.00%
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		300,000						300,000
Total unrecognized compensation cost related to non-vested awards		$ 5,300,000						$ 5,300,000
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding		2,382,000						2,382,000		1,365,000
Total unrecognized compensation cost related to non-vested awards		$ 57,100,000						$ 57,100,000
Expected cost recognized over weighted-average period								2 years 10 months 24 days
Shares repurchased during the period to pay for taxes		3,695			3,343			168,341	228,579
Payments of tax withholdings on restricted stock		$ 200,000			$ 100,000			$ 4,700,000	$ 8,800,000
Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available for stock-based awards	2,141,807
Shares available for future issuance	3,600,000
Vesting period	1 year