Revenue Recognition (Schedule of Disaggregation of Revenue by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	$ 198,236	$ 140,926	$ 359,599	$ 245,372
Lease revenue	1,901	2,651	6,689	6,690
Total operating revenues	200,137	143,577	366,288	252,062
Point in Time [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	191,261	131,633	346,106	227,195
Over Time [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	6,975	9,293	13,493	18,177
Irrigation [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	180,759	118,572	326,667	205,929
Lease revenue	0	0	0	0
Total operating revenues	180,759	118,572	326,667	205,929
Irrigation [Member] | Point in Time [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	175,251	110,814	315,383	190,926
Irrigation [Member] | Over Time [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	5,508	7,758	11,284	15,003
Infrastructure [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	17,477	22,354	32,932	39,443
Lease revenue	1,901	2,651	6,689	6,690
Total operating revenues	19,378	25,005	39,621	46,133
Infrastructure [Member] | Point in Time [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	16,010	20,819	30,723	36,269
Infrastructure [Member] | Over Time [Member]
Disaggregation Of Revenue [Line Items]
Revenue from the contracts with customers	$ 1,467	$ 1,535	$ 2,209	$ 3,174