Earnings Per Share and Dividends (Earnings Per Share) (Details) - shares |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Feb. 28, 2022 |
Feb. 28, 2021 |
Feb. 28, 2022 |
Feb. 28, 2021 |
|
| Restricted stock units | ||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
| Common shares excluded from computation of diluted earnings per share (in shares) | 465,600 | 1,103,500 | 465,600 | 1,074,200 |
| Employee stock purchase plan | ||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
| Common shares excluded from computation of diluted earnings per share (in shares) | 0 | 0 | 0 | 1,900 |