Trade Accounts Receivable Securitization and Sale Programs - Additional Information (Detail) (USD $)	3 Months Ended
	Nov. 30, 2012	Nov. 30, 2011
Trade Accounts Receivable Sale Programs
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Trade accounts receivable sold	$ 700,000,000	$ 500,000,000
Cash proceeds for sale of trade accounts receivable	700,000,000	500,000,000
Asset-Backed Securitization Programs
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Percentage of trade account receivables sold to conduits by wholly-owned subsidiary	100.00%
Trade accounts receivable sold	2,100,000,000	2,100,000,000
Cash proceeds for sale of trade accounts receivable	1,700,000,000	1,600,000,000
Deferred purchases price receivable	436,900,000	497,900,000
Pretax losses on sale of trade accounts receivable	1,100,000	1,800,000
North American Asset-Backed Securitization Program
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program	300,000,000
Foreign Asset-Backed Securitization Program
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program	200,000,000
Trade Accounts Receivable Factoring Agreement
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Trade accounts receivable sold	14,200,000	21,400,000
Cash proceeds for sale of trade accounts receivable	14,200,000	21,400,000
200.0 Million Dollar Trade Accounts Receivable Sale Program | Trade Accounts Receivable Sale Programs
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program	200,000,000
Trade accounts receivable sale agreement expiration date	May 28, 2013
200.0 Million Dollar Trade Accounts Receivable Sale Program | Trade Accounts Receivable Sale Programs | Before amendment
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program	250,000,000
150.0 Million Dollar Trade Accounts Receivable Sale Program | Trade Accounts Receivable Sale Programs
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program	150,000,000
Trade accounts receivable sale agreement expiration date	Nov. 28, 2013
40.0 Million Dollar Trade Accounts Receivable Sale Program | Trade Accounts Receivable Sale Programs
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program	$ 40,000,000
Trade accounts receivable sale agreement expiration date	Jun. 01, 2015
Minimum number of days notice required to cancel receivable sale agreements	30 days