Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Nov. 30, 2021	Nov. 30, 2020
Income Statement [Abstract]
Revenues	$ 798,118	$ 492,107
Operating expense:
Cost of goods sold	683,244	420,094
Selling, general and administrative	55,267	49,906
(Income) from joint ventures	(236)	(727)
Restructuring charges and other exit-related activities	22	64
Operating income	59,821	22,770
Interest expense	(1,372)	(1,780)
Other loss, net	(47)	(165)
Income from continuing operations before income taxes	58,402	20,825
Income tax expense	(11,097)	(5,719)
Income from continuing operations	47,305	15,106
Loss from discontinued operations, net of tax	(29)	(42)
Net income	47,276	15,064
Net income attributable to noncontrolling interests	(1,077)	(960)
Net income attributable to SSI shareholders	$ 46,199	$ 14,104
Net income per share attributable to SSI shareholders Basic:
Income per share from continuing operations	$ 1.64	$ 0.51
Net income per share	1.64	0.51
Net income per share attributable to SSI shareholders Diluted:
Income per share from continuing operations	1.55	0.50
Net income per share	$ 1.55	$ 0.50
Weighted average number of common shares:
Basic	28,159	27,807
Diluted	29,885	28,485