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Income Taxes Income Taxes (Tables) | 3 Months Ended
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Nov. 30, 2017
Income Tax Disclosure [Abstract] |
Income Tax Effective Tax Rate [Table Text Block] | Comparative earnings before income taxes, income tax expense (benefit) and effective income tax rates are as follows (amounts in thousands):
| Three Months Ended November 30, |
| 2017 |  | 2016 |
Earnings before income taxes | $ | 6,830 |  |  | $ | 1,967 |  |
Income tax expense (benefit) | 1,604 |  |  | (2,998 | ) |
Effective income tax rate | 23.5 | % |  | (152.4 | )% |

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