Trade Accounts Receivable Securitization and Sale Programs - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2013	May 31, 2012
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Valuation allowance established for accounts receivable		$ 10,149,000		$ 10,149,000
Trade Accounts Receivable Factoring Agreement
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Trade accounts receivable sold	8,500,000	19,200,000	31,200,000	62,600,000
Cash proceeds for sale of trade accounts receivable	8,500,000	19,200,000	31,200,000	62,600,000
Trade Accounts Receivable Sale Programs
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Trade accounts receivable sold	500,000,000	500,000,000	1,900,000,000	1,600,000,000
Cash proceeds for sale of trade accounts receivable	500,000,000	500,000,000	1,900,000,000	1,600,000,000
Asset-Backed Securitization Programs
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Percentage of trade accounts receivable sold to conduits by special purpose entities			100.00%
Trade accounts receivable sold	2,200,000,000	2,100,000,000	6,400,000,000	6,200,000,000
Cash proceeds for sale of trade accounts receivable	1,700,000,000	1,600,000,000	5,900,000,000	5,600,000,000
Deferred purchases price receivable	524,500,000	542,200,000	524,500,000	542,200,000
Valuation allowance established for accounts receivable				10,100,000
Pretax losses on sale of trade accounts receivable	1,100,000	1,400,000	3,200,000	4,500,000
North American Asset-Backed Securitization Program
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Trade accounts receivable sale agreement expiration date			Oct. 31, 2014
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program	300,000,000		300,000,000
Foreign Asset-Backed Securitization Program
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Trade accounts receivable sale agreement expiration date			May 31, 2015
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program	200,000,000		200,000,000
200.0 Million Dollar Trade Accounts Receivable Sale Program | Trade Accounts Receivable Sale Programs
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Trade accounts receivable sale agreement expiration date			Nov. 30, 2013
200.0 Million Dollar Trade Accounts Receivable Sale Program | Trade Accounts Receivable Sale Programs | After 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	200,000,000		200,000,000
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		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]
Trade accounts receivable sale agreement expiration date			Nov. 28, 2013
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program	150,000,000		150,000,000
40.0 Million Dollar Trade Accounts Receivable Sale Program | Trade Accounts Receivable Sale Programs
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Trade accounts receivable sale agreement expiration date			Jun. 01, 2015
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program	$ 40,000,000		$ 40,000,000
Minimum number of days notice required to cancel receivable sale agreements			30 days