Capital Stock (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended
Feb. 28, 2015	Feb. 28, 2014	Feb. 28, 2015	Feb. 28, 2014
Earnings Per Share [Abstract]
Earnings (loss) from continuing operations	$ (64,838)	$ 22,304	$ (40,164)	$ 55,309
Weighted average common shares outstanding - basic	61,759	72,227	63,045	72,656
Net effect of dilutive securities—stock based compensation plans (1)	0	1,546	0	1,736
Weighted average common shares outstanding - diluted	61,759	73,773	63,045	74,392
Basic (in dollars per share)	$ (1.05)	$ 0.31	$ (0.64)	$ 0.76
Diluted (in dollars per share)	$ (1.05)	$ 0.30	$ (0.64)	$ 0.74
Anti-dilutive securities stock based compensation plans (excluded from earnings per share calculation)	4,761	403	4,761	201

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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The amount of net income (loss) from continuing operations per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) derived from continuing operations during the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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