Revenue Recognition (Schedule of Disaggregation of Revenue by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
May 31, 2020	May 31, 2019	May 31, 2020	May 31, 2019
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	$ 120,643	$ 119,636	$ 339,511	$ 337,959
Lease revenue	2,463	1,418	6,776	4,228
Operating revenues	123,106	121,054	346,287	342,187
Irrigation [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	93,523	98,618	267,948	281,994
Lease revenue	0	0	0	0
Operating revenues	93,523	98,618	267,948	281,994
Infrastructure [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	27,120	21,018	71,563	55,965
Lease revenue	2,463	1,418	6,776	4,228
Operating revenues	29,583	22,436	78,339	60,193
Point in Time [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	107,627	108,871	293,786	308,059
Point in Time [Member] \| Irrigation [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	83,128	89,442	229,529	256,466
Point in Time [Member] \| Infrastructure [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	24,499	19,429	64,257	51,593
Over Time [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	13,016	10,765	45,725	29,900
Over Time [Member] \| Irrigation [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	10,395	9,176	38,419	25,528
Over Time [Member] \| Infrastructure [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	$ 2,621	$ 1,589	$ 7,306	$ 4,372

Amount of direct financing lease revenue.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 5
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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-Section 50
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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