Net Earnings Per Share (Schedule of Computation of Basic and Diluted Net Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Feb. 28, 2021	Feb. 29, 2020	Feb. 28, 2021	Feb. 29, 2020
Earnings Per Share [Abstract]
Net earnings	$ 11,876	$ 5,516	$ 18,971	$ 13,861
Weighted average shares outstanding	10,884	10,825	10,865	10,810
Diluted effect of stock awards	97	32	69	33
Weighted average shares outstanding assuming dilution	10,981	10,857	10,934	10,843
Basic net earnings per share	$ 1.09	$ 0.51	$ 1.75	$ 1.28
Diluted net earnings per share	$ 1.08	$ 0.51	$ 1.74	$ 1.28