Industry Segment Information (Schedule of Segment Reporting Information, by Segment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2022	Aug. 31, 2021	Aug. 31, 2020
Segment Reporting Information [Line Items]
Total operating revenues	$ 770,743	$ 567,646	$ 474,692
Total operating income	94,643	54,107	54,202
Total other expense	(6,775)	(3,721)	(5,359)
Earnings before income taxes	87,868	50,386	48,843
Capital expenditures	15,595	26,511	21,445
Depreciation and amortization	20,178	19,177	19,396
Irrigation [Member]
Segment Reporting Information [Line Items]
Total operating revenues	665,829	471,358	349,346
Total operating income	105,763	63,181	41,263
Capital expenditures	10,679	19,188	9,254
Depreciation and amortization	13,011	12,245	12,906
Irrigation [Member] | North America [Member]
Segment Reporting Information [Line Items]
Total operating revenues	355,683	273,871	224,771
Irrigation [Member] | International [Member]
Segment Reporting Information [Line Items]
Total operating revenues	310,146	197,487	124,575
Infrastructure [Member]
Segment Reporting Information [Line Items]
Total operating revenues	104,914	96,288	125,346
Total operating income	18,328	20,174	42,722
Capital expenditures	3,798	6,866	11,275
Depreciation and amortization	3,781	3,748	3,495
Corporate Segment
Segment Reporting Information [Line Items]
Total operating income	(29,448)	(29,248)	(29,783)
Capital expenditures	1,118	457	916
Depreciation and amortization	$ 3,386	$ 3,183	$ 2,994