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Income Taxes - Narrative (Details) - USD ($) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Feb. 29, 2020 | Feb. 23, 2019 | Feb. 29, 2020 | Feb. 23, 2019
Income Tax Disclosure [Abstract] |  |  |  |
Effective income tax rate | 24.20% | 24.90% | 23.00% | 25.50%
Discrete tax benefit due to stock option exercises | $ 700,000 |  | $ 1,400,000 |
Discrete tax benefit resulting from release of tax reserves |  |  | 1,300,000 |
Decrease in unrecognized tax benefits of due to release of tax reserves | $ 0 |  | $ 1,300,000 |

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