Share-Based Compensation (Summary Of Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2015
Share-Based Compensation [Abstract]
Stock options outstanding, number of stock options	127,286	96,376
Granted, number of stock options	47,223	39,999
Exercised, number of stock options	(43,556)	(4,456)
Forfeited/ cancelled, number of stock options	(8,434)	(4,633)
Stock options outstanding, number of stock options	122,519	127,286	96,376
Stock options outstanding, average exercise price	$ 71.24	$ 70.65
Granted, average exercise price	78.23	67.68
Exercised, average exercise price	69.33	25.47
Forfeited/ cancelled, average exercise price	73.90	72.14
Stock options outstanding, average exercise price	$ 74.43	$ 71.24	$ 70.65
Average remaining contractual term (years)	7 years 6 months	7 years 4 months 24 days	7 years 3 months 18 days
Aggregate intrinsic value outstanding	$ 521	$ 710
Exercised aggregate intrinsic value	681	181
Aggregate intrinsic value outstanding	$ 1,487	$ 521	$ 710
Exercisable number of stock options	36,348	57,250	39,449
Exercisable average exercise price	$ 71.37	$ 68.57	$ 61.47
Exercisable average remaining contractual term (years)	5 years 9 months 18 days	6 years 1 month 6 days	6 years 1 month 6 days
Exercisable aggregate intrinsic value	$ 553	$ 362	$ 583