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Earnings Per Share - Reconciliation of Shares Used in Computation of Basic and Diluted Earnings Per Common Share (Detail) - shares shares in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
May 31, 2021 | May 31, 2020 | May 31, 2021 | May 31, 2020
Earnings Per Share Disclosure [Line Items] |  |  |  |  |
Weighted average basic common shares outstanding | [1] | 32,573 | 32,690 | 32,726 | 32,660
Dilutive effect of restricted stock units | [2] | 1,032 | 788 | 1,021 | 754
Weighted average diluted common shares outstanding |  | 33,605 | 33,478 | 33,747 | 33,414
2.875% Convertible senior notes, due 2024 |  |  |  |  |
Earnings Per Share Disclosure [Line Items] |  |  |  |  |
Dilutive effect of convertible notes | [3] | 0 | 0 | 0 | 0
2.875% Convertible Notes Due 2028 |  |  |  |  |
Earnings Per Share Disclosure [Line Items] |  |  |  |  |
Dilutive effect of convertible notes | [4] | 0 | 0 | 0 | 0
2.25% Convertible Notes Due 2024 |  |  |  |  |
Earnings Per Share Disclosure [Line Items] |  |  |  |  |
Dilutive effect of convertible notes | [5] | 0 | 0 | 0 | 0
[1] | Restricted stock grants and restricted stock units that are considered participating securities, including some grants subject to certain performance criteria, are included in weighted average basic common shares outstanding when the Company is in a net earnings position.
[2] | Restricted stock units that are not considered participating securities and restricted stock units subject to performance criteria, for which actual levels of performance above target have been achieved, are included in weighted average diluted common shares outstanding when the Company is in a net earnings position.
[3] | The dilutive effect of the 2.875% convertible notes, due 2024 was excluded for the three and nine months ended May 31, 2021 and 2020 as the average stock price was less than the applicable conversion price and therefore was considered anti-dilutive.
[4] | The dilutive effect of the 2.875% convertible notes, due 2028 was excluded for the three and nine months ended May 31, 2021 as the average stock price was less than the applicable conversion price and therefore was considered anti-dilutive. These convertible notes were issued in April 2021.
[5] | The dilutive effect of the 2.25% convertible notes, due 2024 was excluded for the three and nine months ended May 31, 2021 and 2020 as the average stock price was less than the applicable conversion price and therefore was considered anti-dilutive. These convertible notes were retired in April 2021.

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- Definition Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of convertible debt securities using the if-converted method. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 40 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e1930-109256 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 42 -URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e2029-109256 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 + Details
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- Definition Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e1707-109256 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 28A -URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e1500-109256 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 23 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e1757-109256 + Details
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