Income Taxes (Provision For Income Taxes Computed By Applying The Statutory Federal Income Tax Rate) (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2016	Aug. 31, 2015	Aug. 31, 2014
Income Taxes [Abstract]
Amount computed by applying a tax rate of 35%	$ 32,377	$ 32,103	$ 25,818
State income taxes (net of federal income tax benefit)	2,553	1,330	2,562
Employment related and other tax credits, net	(2,324)	(2,096)	(1,537)
Change in uncertain tax positions	(3,027)
Federal tax benefit of statutory tax deduction		(4,093)
Other	(1,142)	(7)	(995)
Provision for income taxes	$ 28,437	$ 27,237	$ 25,848
Statutory federal income tax rate	35.00%