Earnings Per Share and Dividends (Earnings Per Share) (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	May 31, 2020	May 31, 2019	May 31, 2020	May 31, 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	3,717	1,345	3,379	1,338
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	57	0	92	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	5	0	28	0