Derivative Financial Instruments (Textual) (Details) (USD $)	12 Months Ended
	Apr. 30, 2013	Apr. 30, 2012 bu
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Outstanding foreign currency contracts with notional amounts	$ 686,000,000	$ 510,000,000
Outstanding exchange-traded futures and options contracts of corn (bushel)		2,000,000
Fixed-to-floating interest rate swaps outstanding with a notional value	0	125,000,000
Net losses recorded in AOCI expected to reclassify to earnings during the next 12 months	1,000,000
Maximum term of outstanding derivative contracts (months)	24 months	24 months
Aggregate fair value of derivatives with creditworthiness requirements that were in a net liability position	$ 2,000,000	$ 4,000,000