Derivative Financial Instruments (Details 1) (USD $) In Millions	3 Months Ended
	Jul. 31, 2011	Jul. 31, 2010
Currency Derivatives [Member] | Sales [Member] | Cash Flow Hedging [Member]
Fair values of derivative instruments affecting statements of operations
Net gain (loss) reclassified from AOCI into income	$ (5.3)	$ 3.9
Currency Derivatives [Member] | Sales [Member] | Not designated as hedges [Member]
Fair values of derivative instruments affecting statements of operations
Gain (loss) on derivative instruments recognized in income	0.7	0.8
Commodity derivatives [Member] | Cost of Sales [Member] | Not designated as hedges [Member]
Fair values of derivative instruments affecting statements of operations
Gain (loss) on derivative instruments recognized in income	(1.2)	0.3
Currency Derivatives [Member] | Other Income [Member] | Not designated as hedges [Member]
Fair values of derivative instruments affecting statements of operations
Gain (loss) on derivative instruments recognized in income	(1.2)	0.7
Interest Rate Swap [Member] | Other Income [Member] | Fair Value Hedging [Member]
Fair values of derivative instruments affecting statements of operations
Gain (loss) on derivative instruments recognized in income	0.9	1.8
Interest Rate Swap [Member] | Interest Expense [Member] | Fair Value Hedging [Member]
Fair values of derivative instruments affecting statements of operations
Gain (loss) on derivative instruments recognized in income	0.9	0.5
Currency Derivatives [Member] | Cash Flow Hedging [Member]
Fair values of derivative instruments affecting statements of operations
Net gain (loss) recognized in AOCI	1.1
Currency Derivatives [Member] | Net Investment Hedging [Member]
Fair values of derivative instruments affecting statements of operations
Net gain (loss) recognized in AOCI		$ (0.9)