Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021
Income Statement [Abstract]
Revenues	$ 783,198	$ 600,111	$ 1,581,316	$ 1,092,218
Operating expense:
Cost of goods sold	670,539	487,025	1,353,783	907,119
Selling, general and administrative	61,081	54,142	116,348	104,048
(Income) from joint ventures	(591)	(454)	(827)	(1,181)
Restructuring charges and other exit-related activities	4	814	26	878
Operating income	52,165	58,584	111,986	81,354
Interest expense	(1,901)	(1,224)	(3,273)	(3,004)
Other loss, net	(55)	(242)	(102)	(407)
Income from continuing operations before income taxes	50,209	57,118	108,611	77,943
Income tax expense	(12,073)	(11,469)	(23,170)	(17,188)
Income from continuing operations	38,136	45,649	85,441	60,755
Income (loss) from discontinued operations, net of tax	29	30		(12)
Net income	38,165	45,679	85,441	60,743
Net income attributable to noncontrolling interests	(550)	(1,091)	(1,627)	(2,051)
Net income attributable to SSI shareholders	$ 37,615	$ 44,588	$ 83,814	$ 58,692
Net income per share attributable to SSI shareholders Basic:
Income per share from continuing operations	$ 1.33	$ 1.59	$ 2.97	$ 2.10
Net income per share	1.33	1.59	2.97	2.10
Net income per share attributable to SSI shareholders Diluted:
Income per share from continuing operations	1.27	1.54	2.81	2.05
Net income per share	$ 1.27	$ 1.54	$ 2.81	$ 2.05
Weighted average number of common shares:
Basic	28,231	27,991	28,195	27,899
Diluted	29,712	28,862	29,798	28,673