Net Income (Loss) Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Feb. 28, 2014	Feb. 28, 2013
Earnings Per Share [Abstract]
Net income (loss)	$ 2,640	$ 8,743	$ (2,728)	$ 7,299
Net income attributable to noncontrolling interests	(851)	(100)	(1,712)	(329)
Net income (loss) attributable to SSI	$ 1,789	$ 8,643	$ (4,440)	$ 6,970
Computation of shares:
Weighted average common shares outstanding, basic	26,825,000	26,640,000	26,790,000	26,597,000
Incremental common shares attributable to dilutive stock options, performance share awards, DSUs and RSUs	122,000	141,000	0	154,000
Weighted average common shares outstanding, diluted	26,947,000	26,781,000	26,790,000	26,751,000
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	591,662	599,184	1,175,976	622,664