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Equity - Additional Information (Detail) - USD ($) | 12 Months Ended |
--- | --- | ---
Aug. 31, 2021 | Aug. 31, 2020 | Aug. 31, 2019 | Jan. 06, 2021
Stockholders Equity Note [Line Items] |  |  |  |
Shares repurchased | $ 20,000,000.0 |  |  |
Shares available for grant | 1,618,230 | 465,636 | 849,522 |
Performance based share based compensation and dividend equivalent rights | 538,260 | 469,825 | 313,540 |
Share based compensation, non vested shares | 622,528 |  |  |
Additional shares available for grant | 622,528 |  |  |
Unamortized compensation cost of restricted stock unit grants | $ 13,300,000 |  |  |
Share Repurchase Program - 2014 |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |
Remaining authorized repurchase amount | $ 100,000,000.0 |  |  |
Repurchase program expiration date | Jan. 31, 2023 |  |  |
Repurchase of common stock, shares | 0 | 0 |  |
Selling, Administrative and Cost of Revenue |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |
Restricted stock compensation expense | $ 14,700,000 | $ 8,700,000 | $ 12,400,000 |
Restricted Stock | Minimum |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |
Vesting period of compensation expense | 1 year |  |  |
Restricted Stock | Maximum |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |
Vesting period of compensation expense | 3 years |  |  |
Unvested Restricted Stock Grants |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |
Share based compensation, non vested shares | 1,023,504 | 883,933 |  |
Fair value of awards granted | $ 18,000,000.0 | $ 14,500,000 | $ 17,400,000 |
2021 Stock Incentive Plan and 2017 Amended and Restated Stock Incentive Plan |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |
Number of shares reserved for future issuance |  |  |  | 1,500,000
2021 Stock Incentive Plan and 2017 Amended and Restated Stock Incentive Plan | Maximum |  |  |  |
Stockholders Equity Note [Line Items] |  |  |  |
Shares available for grant |  |  |  | 465,636
Number of common shares outstanding |  |  |  | 883,933

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- Definition Aggregate number of common shares reserved for future issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
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