CONDENSED CONSOLIDATED STATEMENTS OF EARNINGS (UNAUDITED) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		May 31, 2020	May 31, 2019	May 31, 2020		May 31, 2019
Income Statement [Abstract]
Net sales		$ 1,341,683	$ 1,605,872	$ 4,067,354		$ 4,285,997
Costs and expenses:
Cost of goods sold		1,116,353	1,364,242	3,385,963		3,735,168
Selling, general and administrative expenses		115,965	115,446	342,502		331,389
Interest expense		15,409	18,513	47,875		53,671
Asset impairments		5,983	15	6,513		15
Total costs and expenses		1,253,710	1,498,216	3,782,853		4,120,243
Earnings from continuing operations before income taxes		87,973	107,656	284,501		165,754
Income taxes		23,804	29,105	73,981		52,855
Earnings from continuing operations		64,169	78,551	210,520		112,899
Earnings (loss) from discontinued operations before income taxes		745	(190)	1,941		(808)
Income taxes (benefit)		180	(29)	581		109
Earnings (loss) from discontinued operations		565	(161)	1,360		(917)
Net earnings		$ 64,734	$ 78,390	$ 211,880		$ 111,982
Basic earnings per share*
Earnings from continuing operations (in USD per share)	[1]	$ 0.54	$ 0.67	$ 1.77		$ 0.96
Earnings (loss) from discontinued operations (in USD per share)		0	0	0.01	[1]	(0.01)	[1]
Net earnings (in USD per share)		0.54	0.66	1.78	[1]	0.95	[1]
Diluted earnings per share*
Earnings from continuing operations (in USD per share)	[1]	0.53	0.66	1.75		0.95
Earnings (loss) from discontinued operations (in USD per share)		0	0	0.01	[1]	(0.01)	[1]
Net earnings (in USD per share)		$ 0.54	$ 0.66	$ 1.76	[1]	$ 0.94	[1]
Average basic shares outstanding		119,192,962	118,045,362	118,828,870		117,762,945
Average diluted shares outstanding		120,278,741	119,145,566	120,277,737		119,013,014

[1] *Earnings Per Share ("EPS") is calculated independently for each component and may not sum to Net EPS due to rounding