Aggregate proceeds received by the entity during the annual period from exercises of stock or unit options and conversion of similar instruments granted under equity-based payment arrangements.

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Unrecognized cost of unvested share-based compensation awards.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Disclosure of the aggregate tax benefit realized from the exercise of stock options and the conversion of similar instruments during the annual period.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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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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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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Net number of share options (or share units) granted during the period.

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

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Share-based Compensation Expense - Additional Information (Detail) - USD ($) $ in Millions		12 Months Ended
	Nov. 04, 1985	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014	Jan. 21, 2014	Jan. 23, 2012	Jan. 29, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of stock options exercised		$ 0.9	$ 4.3	$ 1.9
Cash received from exercise of stock options		4.2	7.3	4.9
Total fair value of restricted stock grants vested in period		8.2	9.8	24.9
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax benefit realized for tax deduction from option exercises		$ 0.1	$ 0.1	$ 0.1
Outstanding Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted		0
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares authorized to be granted	700,000
Share-based compensation arrangement by share-based payment award, purchase price of common stock, percent	85.00%
Total Shareholders Return Performance-based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, grants in period		24,821	28,455	27,450
Non-GAAP EPS Performance-Based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, grants in period		32,444	36,641	35,686
Time Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vesting Period		3 years
2009 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares authorized to be granted					4,453,518	2,200,000	1,600,000
Remaining number of shares available for issuance		2,828,781
Stock Option and Restricted Stock Bonus Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to non-vested share-based compensation arrangements		$ 9.1
Unrecognized compensation cost related to non-vested share-based compensation arrangements, weighted average period		1 year