Acquisitions and Divestitures (Narrative) (Details) $ in Thousands		3 Months Ended	9 Months Ended
	Apr. 08, 2020 USD ($)	Feb. 29, 2020 USD ($)	May 31, 2020 USD ($)	May 31, 2019 USD ($)	Aug. 31, 2019 USD ($)	Aug. 31, 2018 Facility
Acquisitions And Divestitures [Line Items]
Net of cash acquired, paid in cash			$ 3,034	$ 0
Goodwill			67,635	64,454	$ 64,387
Loss on sale of irrigation dealership			0	301
Note receivable from sale of business			0	5,589
Assets held-for-sale			0	2,744	$ 2,744
Net proceeds from the sale of building		$ 3,900	3,955	0
Gain from the sale of building		$ 1,200	$ 1,191	0
North America [Member] | Infrastructure [Member]
Acquisitions And Divestitures [Line Items]
Number of manufacturing facilities closed | Facility						1
General and Administrative Expense [Member]
Acquisitions And Divestitures [Line Items]
Loss on sale of irrigation dealership				$ 300
Net Irrigate, LLC [Member]
Acquisitions And Divestitures [Line Items]
Acquisition date	Apr. 08, 2020
Total purchase price	$ 4,500
Net of cash acquired, paid in cash	3,000
Cash payable	$ 300
Cash payable period	90 days
Earn-out liability payment period	1 year
Earn-out payment amount	$ 1,200
Maximum potential payout	1,500
Goodwill	3,200
Business combination, various other assets and liabilities	$ 1,300