Net Income (Loss) Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Aug. 31, 2013	May 31, 2013	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	May 31, 2012	Feb. 29, 2012	Nov. 30, 2011	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Earnings Per Share [Abstract]
Income (loss) from continuing operations									$ (280,023)	$ 28,917	$ 123,637
Net income attributable to noncontrolling interests									(1,419)	(1,513)	(5,181)
Income (loss) from continuing operations attributable to SSI									(281,442)	27,404	118,456
Loss from discontinued operations, net of tax									0	0	(101)
Net income (loss) attributable to SSI	$ (289,234)	$ 820	$ 8,643	$ (1,671)	$ (485)	$ 11,241	$ 9,630	$ 7,018	$ (281,442)	$ 27,404	$ 118,355
Computation of shares:
Weighted average common shares outstanding, basic									26,656,000	27,317,000	27,649,000
Incremental common shares attributable to dilutive stock options, performance share awards, DSUs and RSUs									0	236,000	310,000
Weighted average common shares outstanding, diluted									26,656,000	27,553,000	27,959,000
Antidilutive securities excluded from computation of earnings per share									957,235	69,081	39,820