Goodwill And Other Intangible Assets (Carrying Amount In Goodwill By Segments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2016	Aug. 31, 2015
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 76,801	$ 37,021
Foreign currency translation	2	(1,099)
Goodwill, Ending Balance	76,803	76,801
Elecsys [Member]
Goodwill [Line Items]
Acquisition		39,986
SPF Water Engineering [Member]
Goodwill [Line Items]
Acquisition		893
Irrigation [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	60,905	20,293
Foreign currency translation	37	(267)
Goodwill, Ending Balance	60,942	60,905
Irrigation [Member] | Elecsys [Member]
Goodwill [Line Items]
Acquisition		39,986
Irrigation [Member] | SPF Water Engineering [Member]
Goodwill [Line Items]
Acquisition		893
Infrastructure [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	15,896	16,728
Foreign currency translation	(35)	(832)
Goodwill, Ending Balance	$ 15,861	$ 15,896