Revenue Recognition (Schedule of Disaggregation of Revenue by Segment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2021	Aug. 31, 2020	Aug. 31, 2019
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	$ 551,283	$ 463,207
Lease revenue	16,363	11,485
Total operating revenues	567,646	474,692	$ 444,072
Irrigation [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	471,358	349,346
Lease revenue	0	0
Total operating revenues	471,358	349,346	358,548
Infrastructure [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	79,925	113,861
Lease revenue	16,363	11,485
Total operating revenues	96,288	125,346	$ 85,524
Point in Time [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	512,822	409,380
Point in Time [Member] | Irrigation [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	438,594	304,326
Point in Time [Member] | Infrastructure [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	74,228	105,054
Over Time [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	38,461	53,827
Over Time [Member] | Irrigation [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	32,764	45,020
Over Time [Member] | Infrastructure [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	$ 5,697	$ 8,807