DEBT (Summary of Changes in Long-Term Debt) (Details) - USD ($)	12 Months Ended
	Aug. 31, 2018		Aug. 31, 2017		Aug. 31, 2016
Debt Instrument [Line Items]
Current portion of long-term debt	$ 18,358,000		$ 14,565,000
Long-term debt (net of current portion)	87,939,000		73,542,000
Total	106,297,000	[1]	88,107,000	[2]
Proceeds from long-term debt total	28,500,000		47,700,000		$ 14,370,000
Regularly scheduled loan payments, Current	(4,052,000)		(225,000)
Regularly scheduled loan payments, Noncurrent	12,673,000		(15,837,000)
Regularly scheduled loan payments total	(16,725,000)		(16,062,000)
Reclassification of long-term debt, Current	3,005,000
Reclassification of long-term debt, Noncurrent	(3,005,000)
Translation adjustments on foreign-currency debt of subsidiaries whose functional currency is not the U.S. dollar, Current	144,000	[3]	18,000
Translation adjustments on foreign-currency debt of subsidiaries whose functional currency is not the U.S. dollar, Noncurrent	(278,000)	[3]	(133,000)
Translation adjustments on foreign-currency debt of subsidiaries whose functional currency is not the U.S. dollar total	(134,000)	[3]	(115,000)
Current portion of long-term debt	14,855,000		18,358,000		14,565,000
Long-term debt (net of current portion)	87,720,000		87,939,000		73,542,000
Total	102,575,000	[4]	106,297,000	[1]	88,107,000	[2]
Panama Subsidiary [Member]
Debt Instrument [Line Items]
Proceeds from long-term debt incurred during the period, Current	1,500,000
Proceeds from long-term debt incurred during the period, Noncurrent	13,500,000
Proceeds from long-term debt total	15,000,000
Repayments of long-term debt, Current			(2,000,000)
Repayments of long-term debt, Noncurrent			(11,333,000)
Repayments of long-term debt total			(13,333,000)
Honduras Subsidiary [Member]
Debt Instrument [Line Items]
Proceeds from long-term debt incurred during the period, Current	1,350,000
Proceeds from long-term debt incurred during the period, Noncurrent	12,150,000
Proceeds from long-term debt total	13,500,000
Trinidad Subsidiary [Member]
Debt Instrument [Line Items]
Proceeds from long-term debt incurred during the period, Current			6,000,000
Proceeds from long-term debt incurred during the period, Noncurrent			6,000,000
Proceeds from long-term debt total			12,000,000
Repayments of long-term debt, Current	(3,000,000)
Repayments of long-term debt, Noncurrent	(3,000,000)
Repayments of long-term debt total	(6,000,000)
Cash Asset [Member]
Debt Instrument [Line Items]
Debt Instrument, Collateral amount	0		0		0
NonCash Asset [Member]
Debt Instrument [Line Items]
Debt Instrument, Collateral amount	125,900,000		128,400,000		$ 102,400,000
Union Bank [Member]
Debt Instrument [Line Items]
Proceeds from long-term debt incurred during the period, Noncurrent			35,700,000
Proceeds from long-term debt total			$ 35,700,000
Scotiabank [Member] | Honduras Subsidiary [Member]
Debt Instrument [Line Items]
Repayments of long-term debt, Current	(600,000)
Repayments of long-term debt, Noncurrent	(850,000)
Repayments of long-term debt total	(1,450,000)
Citibank [Member] | Honduras Subsidiary [Member]
Debt Instrument [Line Items]
Repayments of long-term debt, Current	(1,850,000)
Repayments of long-term debt, Noncurrent	(6,063,000)
Repayments of long-term debt total	$ (7,913,000)

[1] The carrying amount on non-cash assets assigned as collateral for these loans was $128.4 million. No cash assets were assigned as collateral for these loans.

[2] The carrying amount on non-cash assets assigned as collateral for these loans was $102.4 million. No cash assets were assigned as collateral for these loans.

[3] These foreign currency translation adjustments are recorded within other comprehensive income.

[4] The carrying amount on non-cash assets assigned as collateral for these loans was $125.9 million. No cash assets were assigned as collateral for these loans as of August 31, 2017.