Supplemental Cash Flow Disclosures (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Nov. 30, 2014	Nov. 30, 2013
Supplemental Cash Flow Disclosures [Abstract]
Capital lease obligation additions	$ 32wag_CapitalLeaseObligationAdditions
Cash paid for interest	43us-gaap_InterestPaid	41us-gaap_InterestPaid
Cash paid for income taxes	$ 18us-gaap_IncomeTaxesPaid	$ 45us-gaap_IncomeTaxesPaid

The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4297-108586

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3536-108585

Name:	us-gaap_IncomeTaxesPaid
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration