Long-Term Debt (Schedule of Long-Term Debt) (Details) - USD ($) $ in Thousands	Feb. 28, 2019	Aug. 31, 2018	Feb. 28, 2018
Debt Instrument [Line Items]
Total debt	$ 116,673	$ 116,775	$ 116,876
Less current portion	(207)	(205)	(203)
Total long-term debt	116,466	116,570	116,673
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total debt	0	0	0
Elecsys Series 2006A Bonds [Member]
Debt Instrument [Line Items]
Total debt	1,673	1,775	1,876
Series A Senior Notes [Member]
Debt Instrument [Line Items]
Total debt	$ 115,000	$ 115,000	$ 115,000

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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