CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Total
Balance at Aug. 31, 2018	$ 939	$ 13,104	$ (12,336)	$ 245,049	$ 246,756
Balance (in shares) at Aug. 31, 2018	9,396,947
Increase (Decrease) in Stockholders' Equity
Restricted stock grants, net of forfeitures	$ 1	(1)
Restricted stock grants, net of forfeitures (in shares)	4,709
Amortization of restricted stock grants		380			380
Amortization of stock option grants		125			125
Exercise of stock options		120			120
Exercise of stock options (in shares)	2,004
Common stock received for payment of stock option exercises		(120)			(120)
Common stock received for payment of stock option exercises (in shares)	(954)
Cash dividend accrued				(7,522)	(7,522)
Change in funded status of pension plans, net of tax			236		236
Foreign currency translation adjustment			(606)		(606)
Net unrealized gain (loss) on restricted investments, net of tax			(21)		(21)
Net income				8,823	8,823
Balance at Nov. 30, 2018	$ 940	13,608	(12,727)	246,372	248,193
Balance (in shares) at Nov. 30, 2018	9,402,706
Increase (Decrease) in Stockholders' Equity
Adoption of new accounting standard | ASU 2014-09				22	22
Balance at Aug. 31, 2019	$ 940	14,351	(14,324)	270,260	271,227
Balance (in shares) at Aug. 31, 2019	9,400,748
Increase (Decrease) in Stockholders' Equity
Restricted stock grants, net of forfeitures	$ 2	(2)
Restricted stock grants, net of forfeitures (in shares)	20,637
Amortization of restricted stock grants		486			486
Amortization of stock option grants		228			228
Exercise of stock options		123			123
Exercise of stock options (in shares)	3,618
Common stock received for payment of stock option exercises		(123)			(123)
Common stock received for payment of stock option exercises (in shares)	(1,057)
Cash dividend accrued				(7,539)	(7,539)
Change in funded status of pension plans, net of tax			131		131
Foreign currency translation adjustment			1,537		1,537
Net unrealized gain (loss) on restricted investments, net of tax			41		41
Net income				7,362	7,362
Balance at Nov. 30, 2019	$ 942	$ 15,063	(14,003)	271,471	$ 273,473
Balance (in shares) at Nov. 30, 2019	9,423,946
Increase (Decrease) in Stockholders' Equity
Adoption of new accounting standard | ASU 2018-02			(1,388)	$ 1,388
Adoption of new accounting standard			$ (1,388)