Debt - Additional Information (Detail) (USD $)			1 Months Ended					12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Nov. 08, 2010 10-year 3.25% notes [Member]	Nov. 03, 2011 10-year 3.125% notes [Member]	Nov. 08, 2010 30-year 5.00% notes [Member]	Nov. 03, 2011 5-year 1.75% notes [Member]	Sep. 30, 2012 Foreign Debt [Member]	Sep. 30, 2012 Syndicated Credit Facility [Member] Domestic Debt [Member]
Debt Instrument [Line Items]
Short-term Debt, Weighted Average Interest Rate	1.35%	1.20%
Maximum borrowing capacity of syndicated credit facility								$ 1,000,000,000
Expiration date of syndicated credit facility								May 31, 2017
Additional commitments made by the lenders	500,000,000
Maximum aggregate commitment	1,500,000,000
Restrictive covenant description								Requires a minimum interest coverage ratio
Restrictive covenant compliance								In compliance
Borrowings outstanding under syndicated credit facility								0
Unused short-term foreign lines of credit pursuant to informal arrangements							309,481,000
Face amounts of notes due			700,000,000	1,000,000,000	300,000,000	500,000,000
Debt instrument maturity period (years)			10-year	10-year	30-year	5-year
Face amounts of notes due			3.25%	3.125%	5.00%	1.75%
Aggregate annual maturities of long-term debt, 2013	202,404,000
Aggregate annual maturities of long-term debt, 2014	3,000
Aggregate annual maturities of long-term debt, 2015	0
Aggregate annual maturities of long-term debt, 2016	0
Aggregate annual maturities of long-term debt, 2017	$ 497,388,000