Stocks Plans - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
Aug. 31, 2015	Aug. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Class A Common Stock were authorized for issuance	9,400,000
Shares available for future grants	2,700,793
Exercise price as percentage of fair market value at grant date	100.00%
Unrecognized compensation cost related to share-based compensation for stock options and restricted stock outstanding	$ 23.8
Unrecognized compensation cost related to share-based compensation for stock options and restricted stock outstanding, recognition period	3 years 22 days
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period	3 years
Performance Shares \| Free Cash Flow Conversion Target
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	50.00%
Performance Shares \| Total Shareholders Return
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	50.00%
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of shares vested	$ 14.2	$ 17.9
After Three Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	50.00%
After Five Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	100.00%
Maximum \| Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options term	10 years

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Unrecognized cost of unvested share-based compensation awards.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

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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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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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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 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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Percentage of vesting of share-based compensation awards.

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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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