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Stocks Plans - Additional Information (Detail) - USD ($) $ in Millions | 12 Months Ended
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Aug. 31, 2019 | Aug. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Class A Common Stock were authorized for issuance | 4,325,000 |
Common Stock Registered to Cover Shares that Become Issuable | 1,800,000 |
Shares available for future grants | 3,212,656 |
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 | $ 18.9 |
Unrecognized compensation cost related to share-based compensation for stock options and restricted stock outstanding, recognition period | 1 year 11 months |
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 | $ 11.9 | $ 14.3
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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- Definition Common Stock Registered to Cover Shares that Become Issuable, pursuant to the terms of the Plan, upon the expiration, cancellation or forfeiture of existing awards under the previously registered stock plans. + References No definition available. + Details
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- Definition Unrecognized cost of unvested share-based compensation awards. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition 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). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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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 Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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