Industry Segment Information (Schedule of Segment Reporting Information Impacts on Statement of Operations, by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021
Segment Reporting Information [Line Items]
Total operating revenues	$ 200,137	$ 143,577	$ 366,288	$ 252,062
Total operating income	18,338	15,809	31,699	23,343
Interest and other expense, net	866	(1,248)	(3,019)	(1,900)
Earnings before income taxes	19,204	14,561	28,680	21,443
Irrigation [Member]
Segment Reporting Information [Line Items]
Total operating revenues	180,759	118,572	326,667	205,929
Total operating income	24,734	18,045	41,946	28,678
Irrigation [Member] | North America [Member]
Segment Reporting Information [Line Items]
Total operating revenues	100,730	80,178	179,705	132,968
Irrigation [Member] | International [Member]
Segment Reporting Information [Line Items]
Total operating revenues	80,029	38,394	146,962	72,961
Infrastructure [Member]
Segment Reporting Information [Line Items]
Total operating revenues	19,378	25,005	39,621	46,133
Total operating income	324	6,341	3,090	10,597
Corporate Segment
Segment Reporting Information [Line Items]
Total operating income	$ (6,720)	$ (8,577)	$ (13,337)	$ (15,932)