Financial Instruments and Risk Management - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2013 bu	Jun. 30, 2012 bu
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fixed-price purchase commitment contracts of bushels of corn	17,200,000	23,600,000
Outstanding derivative contracts, net volume	13,400,000	20,400,000
Open physical delivery fixed-price purchase commitment contracts	1,400,000	900,000
Outstanding derivative contracts to sell bushels of corn	2,300,000	3,200,000
Maturities of notes payable	$ 0	$ 350,000,000	[1]
Deferred loss charged to income	1,500,000	800,000
Interest expense due to deferred loss on interest rate swaps during the remaining nine months of 2013	1,500,000
Commodity derivative contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cash deposits related to commodity derivative contracts	12.3
Commodity derivative contracts | Corn
Derivative Instruments and Hedging Activities Disclosures [Line Items]
(Increase) decrease in income before taxes due to the impact of marking to market of derivative contracts	1,500,000	300,000
Foreign exchange derivative contract
Derivative Instruments and Hedging Activities Disclosures [Line Items]
(Increase) decrease in income before taxes due to the impact of marking to market of derivative contracts	5,600,000	9,200,000
Foreign exchange derivative contract | Currency, Malaysian ringgit
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Short-term derivative instruments	153,400,000	235,600,000
Foreign exchange derivative contract | Currency, U.S. Dollar
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Short-term derivative instruments	48,000,000	13,000,000
Interest Rate Swap
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Loss deferred for fair value of interest rate derivative contracts, net of tax	26,300,000
Loss deferred for fair value of interest rate derivative contracts	$ 9,200,000

[1] Reclassified to conform to current presentation.