Changes in Equity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	May. 31, 2015	May. 31, 2014	May. 31, 2015	May. 31, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance - September 1 (Beginning of period)			$ 775,977	$ 781,199
Net income (loss)	$ (8,941)	$ 4,124	(206,422)	1,398
Other comprehensive loss, net of tax	2,411	3,077	(21,096)	(3,521)
Distributions to noncontrolling interests			(2,263)	(1,794)
Restricted stock withheld for taxes			(1,360)	(676)
Stock options exercised			0	240
Share-based compensation			7,596	10,257
Excess tax deficiency from stock options exercised and restricted stock units vested			(703)	(692)
Dividends			(15,415)	(15,185)
Balance - May 31 (End of period)	536,314	771,226	536,314	771,226
SSI Shareholders’ Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance - September 1 (Beginning of period)			770,784	776,558
Net income (loss)			(207,740)	(1,328)
Other comprehensive loss, net of tax			(21,096)	(3,521)
Distributions to noncontrolling interests			0	0
Restricted stock withheld for taxes			(1,360)	(676)
Stock options exercised			0	240
Share-based compensation			7,596	10,257
Excess tax deficiency from stock options exercised and restricted stock units vested			(703)	(692)
Dividends			(15,415)	(15,185)
Balance - May 31 (End of period)	532,066	765,653	532,066	765,653
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance - September 1 (Beginning of period)			5,193	4,641
Net income (loss)			1,318	2,726
Other comprehensive loss, net of tax			0	0
Distributions to noncontrolling interests			(2,263)	(1,794)
Restricted stock withheld for taxes			0	0
Stock options exercised			0	0
Share-based compensation			0	0
Excess tax deficiency from stock options exercised and restricted stock units vested			0	0
Dividends			0	0
Balance - May 31 (End of period)	$ 4,248	$ 5,573	$ 4,248	$ 5,573