Condensed Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Capital In Excess Of Stated Value [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss) Income, Net [Member]
Beginning balance, value at Aug. 31, 2017	$ 270,055	$ 18,780	$ (277,238)	$ 63,006	$ 477,615	$ (12,108)
Beginning balance, shares at Aug. 31, 2017		18,780	8,083
Net earnings (loss)	4,920	$ 0	$ 0	0	4,920	0
Other comprehensive income	849	0	0	0	0	849
Total comprehensive income (loss)	5,769	0	0	0	0	0
Cash dividends per share	(6,444)	0	0	0	(6,444)	0
Issuance of common shares under share compensation plans:
Proceeds from exercise of stock options	2,788	$ 61	0	2,727	0	0
Proceeds from exercise of stock options, shares		61
Common stock withheld for payroll tax obligations	(833)	$ 0	0	(833)	0	0
Share-based compensation expense	1,725	0	0	1,725	0	0
Ending Balance, shares at Feb. 28, 2018	273,060	$ 18,841	$ (277,238)	66,625	476,091	(11,259)
Ending Balance, shares at Feb. 28, 2018		18,841	8,083
Beginning balance, value at Aug. 31, 2018	276,866	$ 18,841	$ (277,238)	68,465	484,886	(18,088)
Beginning balance, shares at Aug. 31, 2018		18,841	8,083
Net earnings (loss)	(2,228)	$ 0	$ 0	0	(2,228)	0
Other comprehensive income	2,025	0	0	0	0	2,025
Total comprehensive income (loss)	(203)	0	0	0	0	0
Cash dividends per share	(6,688)	0	0	0	(6,688)	0
Issuance of common shares under share compensation plans:
Proceeds from exercise of stock options	177	$ 29	0	148	0	0
Proceeds from exercise of stock options, shares		29
Common stock withheld for payroll tax obligations	(1,124)	$ 0	0	(1,124)	0	0
Share-based compensation expense	2,283	0	0	2,283	0	0
Cumulative impact of ASC/ASU adoption | ASC 606 [Member]	532	0	0	0	532	0
Cumulative impact of ASC/ASU adoption | ASU 2018-02 [Member]	0	0	0	0	525	(525)
Ending Balance, shares at Feb. 28, 2019	$ 271,843	$ 18,870	$ (277,238)	$ 69,772	$ 477,027	$ (16,588)
Ending Balance, shares at Feb. 28, 2019		18,870	8,083