Benefit Plans - Schedule of Changes in the Fair value of the Plan's Level 3 Valued Assets (Details) (Pension Plans, Defined Benefit, USD $) In Thousands, unless otherwise specified	12 Months Ended
Aug. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balances at beginning of period	$ 18,252
Unrealized gains (losses)	1,897
Realized losses (gains)	72
Sales	(24)
Purchases	3,418
Transfers into level 3	6
Total	23,621
Real Estate Funds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balances at beginning of period	16,257
Unrealized gains (losses)	1,894
Realized losses (gains)	(10)
Sales
Purchases	15
Total	18,156
Hedge funds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balances at beginning of period	127
Unrealized gains (losses)	7
Realized losses (gains)
Sales	(12)
Purchases
Total	122
Mutual Funds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balances at beginning of period	1,868
Unrealized gains (losses)	(4)
Realized losses (gains)	82
Sales	(12)
Transfers into level 3	6
Total	1,940
Partnership and joint venture interests
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balances at beginning of period
Unrealized gains (losses)
Realized losses (gains)
Sales
Purchases	3,403
Transfers into level 3
Total	$ 3,403

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Amount of gain (loss) recognized in earnings, arising from assets measured at fair value on a recurring basis using unobservable inputs (level 3).

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- Definition

Amount of gain (loss) recognized in other comprehensive income, arising from assets measured at fair value on a recurring basis using unobservable inputs (level 3).

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- Definition

Purchases that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

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- Definition

Sales that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

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- Definition

Transfers into assets measured at fair value and categorized within Level 3 of the fair value hierarchy that have taken place during the period.

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- Definition

This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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