Industry Segment Information (Schedule of Segment Reporting Information Impacts on Statement of Operations, by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2022	May 31, 2021
Segment Reporting Information [Line Items]
Total operating revenues	$ 214,259	$ 161,936	$ 580,547	$ 413,998
Total operating income	35,162	21,341	66,861	44,684
Interest and other expense, net	394	(187)	(2,625)	(2,087)
Earnings before income taxes	35,556	21,154	64,236	42,597
Irrigation [Member]
Segment Reporting Information [Line Items]
Total operating revenues	188,693	140,175	515,360	346,104
Total operating income	39,567	23,925	81,513	52,603
Irrigation [Member] | North America [Member]
Segment Reporting Information [Line Items]
Total operating revenues	96,153	87,364	275,601	220,332
Irrigation [Member] | International [Member]
Segment Reporting Information [Line Items]
Total operating revenues	92,540	52,811	239,759	125,772
Infrastructure [Member]
Segment Reporting Information [Line Items]
Total operating revenues	25,566	21,761	65,187	67,894
Total operating income	3,779	3,767	6,869	14,364
Corporate Segment
Segment Reporting Information [Line Items]
Total operating income	$ (8,184)	$ (6,351)	$ (21,521)	$ (22,283)