Revenue Recognition (Schedule of Disaggregation of Revenue by Segment) (Details) - USD ($)	12 Months Ended
	Aug. 31, 2022	Aug. 31, 2021	Aug. 31, 2020
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	$ 760,263,000	$ 551,283,000
Lease revenue	10,480,000	16,363,000
Total operating revenues	770,743,000	567,646,000	$ 474,692,000
Irrigation [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	665,829,000	471,358,000
Lease revenue	0	0
Total operating revenues	665,829,000	471,358,000	349,346,000
Infrastructure [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	94,434,000	79,925,000
Lease revenue	10,480,000	16,363,000
Total operating revenues	104,914,000	96,288,000	$ 125,346,000
Point in Time [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	731,850,000	512,822,000
Point in Time [Member] | Irrigation [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	643,169,000	438,594,000
Point in Time [Member] | Infrastructure [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	88,681,000	74,228,000
Over Time [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	28,413,000	38,461,000
Over Time [Member] | Irrigation [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	22,660,000	32,764,000
Over Time [Member] | Infrastructure [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	$ 5,753,000	$ 5,697,000