Income Taxes - Uncertain Tax Positions (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2015
Deferred tax assets:
Allowance for doubtful accounts	$ 228	$ 236
Inventories	1,462	1,623
Accruals	800	531
Warranty reserve	120	31
Pension accrual	5,078	5,655
Deferred compensation	358	608
Deferred revenue	334
Loan finance costs	27	32
Restricted stock grants	792	589
Non-qualified stock options	26	15
Foreign other		428
Other	280	11
Deferred tax assets, net	9,505	9,759
Deferred tax liabilities:
Prepaid liabilities	29	44
Unrepatriated earnings	2,298	2,486
Unrealized gain/loss on restricted investments	(177)	(141)
Depreciation and amortization	5,362	8,078
Other	25	16
Noncurrent deferred tax liabilities	(7,891)	(10,765)
Net deferred tax liabilities		(1,006)
Net deferred tax assets	1,614
Adjustments to uncertain tax positions
Balance, at beginning of the year	1,229	1,249	$ 1,030
Increase for tax positions related to the current year	65	37	75
Increase / (decrease) for tax positions related to prior years	16	98
Increase for interest and penalties	6	102	144
Decrease for lapses of statute of limitations	(59)	(257)
Balance, at end of year	1,257	$ 1,229	$ 1,249
Accrued balances related to uncertain tax positions
Accrued interest and penalty	647
Increase in accrued interest and penalty charges recorded as tax benefit	$ 40