Income Taxes - Uncertain Tax Positions (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2019	Aug. 31, 2018	Aug. 31, 2017
Deferred tax assets:
Allowance for doubtful accounts	$ 432	$ 154
Inventories	1,193	982
Accruals	541	584
Warranty reserve	22	50
Pension accrual	2,623	2,567
Deferred compensation	300	260
Foreign currency loss on previously taxed income	96	96
Loan finance costs	34	27
Restricted stock grants	456	547
Non-qualified stock options	258	94
Other	353	296
Deferred tax assets, net	6,308	5,657
Deferred tax liabilities:
Prepaid liabilities	8	25
Unrealized gain/loss on restricted investments		(112)
Depreciation and amortization	2,496	4,173
Noncurrent deferred tax liabilities	(2,504)	(4,310)
Net deferred tax assets	3,804	1,347
Adjustments to uncertain tax positions
Balance, at beginning of the year	1,889	1,257	$ 1,229
Increase for tax positions related to the current year	55	47	65
Increase for tax positions related to prior years	300	595	16
Increase for interest and penalties	106	71	6
Decrease for lapses of statute of limitations	(26)	(81)	(59)
Balance, at end of year	2,324	$ 1,889	$ 1,257
Accrued balances related to uncertain tax positions
Accrued interest and penalty	877
Increase in accrued interest and penalty charges recorded as tax benefit	$ 106