Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		May 31, 2019	May 31, 2018	May 31, 2019	May 31, 2018
Income Statement [Abstract]
Revenues		$ 547,396	$ 652,416	$ 1,584,981	$ 1,695,138
Operating expense:
Cost of goods sold		474,598	549,164	1,379,418	1,427,877
Selling, general and administrative		48,575	54,185	139,483	158,866
(Income) from joint ventures		(311)	(772)	(980)	(1,328)
Asset impairment charges (recoveries), net		0	(1,465)	63	(1,553)
Restructuring charges and other exit-related activities		75	70	813	261
Operating income		24,459	51,234	66,184	111,015
Interest expense		(2,294)	(2,483)	(6,267)	(6,823)
Other income, net		29	403	373	1,353
Income from continuing operations before income taxes		22,194	49,154	60,290	105,545
Income tax expense		(5,762)	(10,650)	(13,733)	(6,030)
Income from continuing operations		16,432	38,504	46,557	99,515
Income (loss) from discontinued operations, net of tax		8	(56)	(202)	72
Net income		16,440	38,448	46,355	99,587
Net income attributable to noncontrolling interests		(750)	(1,046)	(1,585)	(2,806)
Net income attributable to SSI		$ 15,690	$ 37,402	$ 44,770	$ 96,781
Net income per share attributable to SSI Basic:
Income per share from continuing operations attributable to SSI (in dollars per share)		$ 0.57	$ 1.35	$ 1.63	$ 3.49
Loss per share from discontinued operations attributable to SSI (in dollars per share)		0	0	(0.01)	0
Net income per share attributable to SSI (in dollars per share)	[1]	0.57	1.35	1.63	3.49
Net income per share attributable to SSI Diluted:
Income per share from continuing operations attributable to SSI (in dollars per share)		0.56	1.31	1.60	3.38
Loss per share from discontinued operations attributable to SSI (in dollars per share)		0	0	(0.01)	0
Net income per share attributable to SSI (in dollars per share)		$ 0.56	$ 1.31	$ 1.59	$ 3.38
Weighted average number of common shares:
Basic (shares)		27,510	27,676	27,548	27,719
Diluted (Shares)		28,074	28,636	28,184	28,646
Dividends declared per common share (in dollars per share)		$ 0.1875	$ 0.1875	$ 0.5625	$ 0.5625

[1] May not foot due to rounding.