Trade Accounts Receivable Securitization and Sale Programs - Additional Information (Detail) (USD $)	12 Months Ended																3 Months Ended	12 Months Ended				12 Months Ended	3 Months Ended
	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2012 Asset-Backed Securitization Programs	Aug. 31, 2012 North American Asset-Backed Securitization Program	Aug. 31, 2011 North American Asset-Backed Securitization Program	Aug. 31, 2010 North American Asset-Backed Securitization Program	Aug. 31, 2012 Foreign Asset-Backed Securitization Program	Aug. 31, 2011 Foreign Asset-Backed Securitization Program	Aug. 31, 2010 Foreign Asset-Backed Securitization Program	Aug. 31, 2012 Asset-backed Securities	Aug. 31, 2011 Asset-backed Securities	Aug. 31, 2010 Asset-backed Securities	Aug. 31, 2012 Trade Accounts Receivable Factoring Agreement	Aug. 31, 2011 Trade Accounts Receivable Factoring Agreement	Aug. 31, 2010 Trade Accounts Receivable Factoring Agreement	Aug. 31, 2012 Trade Accounts Receivable Sale Programs	Aug. 31, 2012 Trade Accounts Receivable Sale Programs	Aug. 31, 2011 Trade Accounts Receivable Sale Programs	Aug. 31, 2010 Trade Accounts Receivable Sale Programs	May 31, 2012 Trade Accounts Receivable Sale Programs 200.0 Million Dollar Trade Accounts Receivable Sale Program Contract Termination	Aug. 31, 2012 Trade Accounts Receivable Sale Programs 250.0 Million Dollar Trade Accounts Receivable Sale Program	Aug. 31, 2012 Trade Accounts Receivable Sale Programs 40.0 Million Dollar Trade Accounts Receivable Sale Program	Aug. 31, 2012 Trade Accounts Receivable Sale Programs 40.0 Million Dollar Trade Accounts Receivable Sale Program Before amendment	Aug. 31, 2012 Trade Accounts Receivable Sale Programs 40.0 Million Dollar Trade Accounts Receivable Sale Program After amendment
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Percentage of trade account receivables sold to conduits by wholly-owned subsidiary				100.00%
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program					$ 300,000,000			$ 200,000,000													$ 200,000,000	$ 250,000,000		$ 50,000,000	$ 40,000,000
Asset-backed securitization program, amendment date								May 15, 2012
Asset-backed securitization program, expiration date								May 15, 2015
Trade account receivable sold					5,900,000,000	5,800,000,000	5,300,000,000	2,500,000,000	928,000,000					76,000,000	68,500,000	90,900,000		2,100,000,000	2,400,000,000	300,000,000
Cash proceeds for securitization of trade accounts receivable					5,600,000,000	5,500,000,000	5,100,000,000	2,400,000,000	783,900,000					76,000,000	68,400,000	90,800,000		2,100,000,000	2,400,000,000	300,000,000
Deferred purchase price receivable					364,100,000	295,600,000		113,400,000	143,500,000
Interest retained in trade accounts receivables							225,100,000
Interest expense	106,129,000	97,693,000	79,168,000			500,000			900,000	2,100,000
Secured borrowing outstanding										71,400,000
Pretax losses on sale of trade accounts receivable											$ (5,600,000)	$ (3,400,000)	$ (3,600,000)
Minimum number of days notice required to cancel receivable sale agreements																	30 days					30 days
Trade accounts receivable sale agreement expiration date																							Jun. 01, 2015