Earnings Per Share and Dividends (Earnings Per Share) (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Feb. 29, 2020	Feb. 28, 2019	Feb. 29, 2020	Feb. 28, 2019
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common shares excluded from computation of diluted earnings per share	4,499	1,348	1,035	1,348
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	164	0	0	0
Stock appreciation rights
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common shares excluded from computation of diluted earnings per share	28	0	0	0