Pensions and Other Postretirement Benefits - Changes in Fair Value of Pension Plan's Real Estate Equity Fund (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Aug. 31, 2013
Actual return on plan assets:
Balance, August 31, 2013	$ 46,726
Real estate equity funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance, August 31, 2012	2,102
Actual return on plan assets:
Relating to assets still held at the reporting date	246
Relating to assets sold during the period
Purchases and sales
Transfers in (out) of Level 3
Balance, August 31, 2013	$ 2,348

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Actual return on plan assets, separately identifying the amount related to assets sold during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (d)(iv)(02)(A)

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Actual return on plan assets, separately identifying the amount related to assets still held at the reporting date.

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Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)

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Amount of increase (decrease) in plan assets from purchases, sales and settlement of plan obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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Transfers in and out of Level 3. For example, transfers due to changes in the observability of significant inputs.

+ References

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