Stock-Based Compensation (Total Cost Of Share-Based Compensation) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Feb. 28, 2018	Feb. 28, 2017	Feb. 28, 2018	Feb. 28, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	$ 779	$ 1,564	$ 1,736	$ 2,777
Performance Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	582	1,391	1,373	2,469
Unvested Share Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	160	125	292	237
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	$ 37	33	$ 71	56
Fully-Vested Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost		$ 15		$ 15