Financial Instruments and Risk Management - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended
	May 31, 2012	Sep. 30, 2012 bu	Sep. 30, 2011 bu	Sep. 30, 2012 bu	Sep. 30, 2011 bu		Dec. 31, 2011
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Fixed-price purchase commitment contracts of bushels of corn		8,800,000	7,900,000	8,800,000	7,900,000
Outstanding derivative contracts to sell bushels of corn		3,400,000	2,300,000	3,400,000	2,300,000
Open physical delivery fixed-price purchase commitment contracts		1,500,000	1,600,000	1,500,000	1,600,000
Maturities of notes payable matured				$ 350,000,000	$ 0	[1]
Amount of loss reclassified to interest expense in consolidated statements of income		484,000	0	724,000	0
Loss deferred for fair value of interest rate derivative contracts, net of tax		(18,535,000)		(18,535,000)			(16,852,000)
New notes payable issued	500,000,000
New notes maturity date	Jun. 01, 2022
Interest Rate Swap
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Amount of loss reclassified to interest expense in consolidated statements of income		700,000		1,100,000
Loss deferred for fair value of interest rate derivative contracts, net of tax		28,500,000		28,500,000
Derivative contract, maturity date				May 01, 2012
Foreign exchange derivative contract
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Increase (decrease) in income before taxes due to the impact of marking to market of derivative contracts				3,100,000	(2,600,000)
Foreign exchange derivative contract | Currency, Malaysian ringgit
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Short-term derivative instruments		97,600,000	123,300,000	97,600,000	123,300,000
Foreign exchange derivative contract | Currency, U.S. Dollar
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Short-term derivative instruments			38,000,000		38,000,000
Commodity derivative contracts | Corn
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Increase (decrease) in income before taxes due to the impact of marking to market of derivative contracts				6,300,000	1,900,000
Cash collateral deposits		$ 9,200,000		$ 9,200,000

[1] Reclassified to conform to current presentation.