Changes in Equity and Comprehensive Income (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Feb. 29, 2012		Feb. 28, 2011		Feb. 29, 2012		Feb. 28, 2011
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Beginning of Period					$ 1,101,236		$ 979,632
Net Income					18,305	[1]
Net income	10,365		32,134		18,107		51,051
Other Comprehensive Income (Loss), Net of Tax					(2,151)	[2]
Other Comprehensive Income (Loss), Net of Tax	5,266		2,965		(2,368)		3,828
Distributions to Noncontrolling Interests					(2,368)		(1,219)
Share Repurchases					(3,117)		0
Restricted Stock Withheld for Taxes					(840)		(1,880)
Stock Options Exercised					498		279
Share-based Compensation					6,271		6,692
Excess tax benefit (deficiency) from stock options exercised and restricted stock units vested					216		(299)
Cash Dividends (0.034 per share)					(927)		(936)
Dividends declared per common share	$ 0.017		$ 0.017		$ 0.034		$ 0.034
Stockholders' Equity, End of Period	1,117,123		1,037,148		1,117,123		1,037,148
Net Income (Loss) Attributable to Redeemable Noncontrolling Interest					(198)
Foreign Currency Translation Adjustments Attributable To Redeemable Noncontrolling Interest	(669)		0		217		0
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net income	10,365		32,134		18,107		51,051
Foreign Currency Translation Adjustment	5,172	[3]	2,877	[3]	(2,529)	[3]	3,537	[3]
Change in Unrealized gain on Cash Flow Hedges	28	[4]	0	[4]	28	[4]	117	[4]
Pension Obligations, Net	66	[5]	88	[5]	133	[5]	174	[5]
Other Comprehensive Income (Loss), Net of Tax	5,266		2,965		(2,368)		3,828
Total Comprehensive Income	15,631		35,099		15,739		54,879
Less: Net income attributable to Noncontrolling Interest	(735)		(1,309)		(1,462)		(2,432)
Less: Foreign Currency Translation Adjustments Attributable To Redeemable Noncontrolling Interest	(669)		0		217		0
Comprehensive Income Attributable to Noncontrolling Interest	(1,404)		(1,309)		(1,245)		(2,432)
Comprehensive Income Attributable to SSI	14,227		33,790		14,494		52,447
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	343		581		(125)		952
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	16		0		16		66
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax	39		52		78		106
Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Beginning of Period					1,094,712		975,326
Net income					16,645		48,619
Other Comprehensive Income (Loss), Net of Tax					(2,151)	[2]
Other Comprehensive Income (Loss), Net of Tax							3,828
Distributions to Noncontrolling Interests					0		0
Share Repurchases					(3,117)		0
Restricted Stock Withheld for Taxes					(840)		(1,880)
Stock Options Exercised					498		279
Share-based Compensation					6,271		6,692
Excess tax benefit (deficiency) from stock options exercised and restricted stock units vested					216		(299)
Cash Dividends (0.034 per share)					(927)		(936)
Stockholders' Equity, End of Period	1,111,307		1,031,629		1,111,307		1,031,629
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net income					16,645		48,619
Other Comprehensive Income (Loss), Net of Tax							3,828
Noncontrolling Interest [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Beginning of Period					6,524		4,306
Net Income					1,660	[1]
Net income							2,432
Other Comprehensive Income (Loss), Net of Tax					0	[2]
Other Comprehensive Income (Loss), Net of Tax							0
Distributions to Noncontrolling Interests					(2,368)		(1,219)
Share Repurchases					0		0
Restricted Stock Withheld for Taxes					0		0
Stock Options Exercised					0		0
Share-based Compensation							0
Excess tax benefit (deficiency) from stock options exercised and restricted stock units vested					0		0
Cash Dividends (0.034 per share)					0		0
Stockholders' Equity, End of Period	5,816		5,519		5,816		5,519
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net income							2,432
Other Comprehensive Income (Loss), Net of Tax							$ 0

[1] Net income attributable to noncontrolling interests for the six months ended February 29, 2012 excludes a net loss of $198 thousand allocable to the redeemable noncontrolling interest, which is reported in the mezzanine section of the Unaudited Condensed Consolidated Balance Sheets. See Note 8 - Redeemable Noncontrolling Interest.

[2] Other comprehensive income (loss), net of tax for the six months ended February 29, 2012 excludes $(217) thousand relating to foreign currency translation adjustments for the redeemable noncontrolling interest, which is reported in the mezzanine section of the Unaudited Condensed Consolidated Balance Sheets. See Note 8 - Redeemable Noncontrolling Interest.

[3] (1)Net of tax expense (benefit) of $343 thousand, $581 thousand, $(125) thousand and $952 thousand for each respective period.

[4] (2)Net of tax expense of $16 thousand, $0 thousand, $16 thousand and $66 thousand for each respective period.

[5] (3)Net of tax expense of $39 thousand, $52 thousand, $78 thousand and $106 thousand for each respective period.