Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Feb. 28, 2022	Aug. 31, 2021	Feb. 28, 2021
Statement of Financial Position [Abstract]
Receivables, allowance	$ 3,726	$ 3,422	$ 3,021
Preferred stock, par value	$ 1	$ 1	$ 1
Preferred stock, authorized	2,000,000	2,000,000	2,000,000
Preferred stock, issued	0	0	0
Preferred stock, outstanding	0	0	0
Common stock, par value	$ 1	$ 1	$ 1
Common stock, authorized	25,000,000	25,000,000	25,000,000
Common stock, issued	19,061,000	18,991,000	18,990,000
Treasury stock, shares	8,083,000	8,083,000	8,083,000