Income Taxes (Schedule Of Effective income Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2016	Aug. 31, 2015	Aug. 31, 2014
Income Taxes [Abstract]
U.S statutory rate	$ 10,251	$ 16,363	$ 27,529
State and local taxes, net of federal tax benefit	350	911	1,067
Foreign tax rate differences	(377)	1,311	(116)
Domestic production activities deduction	(960)	(1,548)	(2,170)
Deferred tax asset valuation allowance		2,949
Other	(243)	456	833
Total income tax provision	$ 9,021	$ 20,442	$ 27,143
U.S statutory rate, percentage	35.00%	35.00%	35.00%
State and local taxes, net of federal tax benefit, percentage	1.20%	1.90%	1.40%
Foreign tax rate differences, percentage	(1.30%)	2.80%	(0.10%)
Domestic production activities deduction, percentage	(3.30%)	(3.30%)	(2.80%)
Deferred tax asset valuation allowance, percentage		6.30%
Other, percentage	(0.80%)	1.00%	1.00%
Effective rate, percentage	30.80%	43.70%	34.50%