Derivative Financial Instruments (Tables)

3 Months Ended

Jul. 31, 2011

Derivative Financial Instruments (Tables) [Abstract]

Fair value of derivative instruments

	July 31, 2011						April 30, 2011
	Other		Other		Other		Other		Other		Other
	Current		Noncurrent		Current		Current		Current		Noncurrent
	Assets		Assets		Liabilities		Assets		Liabilities		Liabilities
Derivatives designated as hedging instruments:
Commodity contracts	$	914	$	0	$	598	$	3,408	$	0	$	0
Interest rate contract		7,919		10,569		0		5,423		0		1,384
Total derivatives designated as hedging instruments	$	8,833	$	10,569	$	598	$	8,831	$	0	$	1,384
Derivatives not designated as hedging instruments:
Commodity contracts	$	13,092	$	0	$	4,181	$	9,887	$	5,432	$	0
Foreign currency exchange contracts		186		29		1,963		317		3,204		0
Total derivatives not designated as hedging instruments	$	13,278	$	29	$	6,144	$	10,204	$	8,636	$	0
Total derivatives instruments	$	22,111	$	10,598	$	6,742	$	19,035	$	8,636	$	1,384

Gains and losses recognized on derivatives designated as cash flow hedges

	Three Months Ended July 31,
	2011			2010
(Losses) gains recognized in other comprehensive (loss) income (effective portion)	$	(6,014	)	$	8,931
Gains (losses) reclassified from accumulated other comprehensive (loss) income to cost of products sold (effective portion)		6,108			(37	)
Change in accumulated other comprehensive (loss) income	$	(12,122	)	$	8,968
(Losses) gains recognized in cost of products sold (ineffective portion)	$	(121	)	$	171

Gains and losses recognized in cost of products sold on derivatives not designated as qualified hedging instruments

	Three Months Ended
	July 31,
	2011		2010
Gains on commodity contracts	$	13,697	$	4,393
Gains on foreign currency exchange contracts		85		477
Gains recognized in cost of products sold (derivatives not designated as hedging instruments)	$	13,782	$	4,870

Outstanding derivative contracts

	July 31, 2011		April 30, 2011
Commodity contracts	$	965,726	$	869,107
Foreign currency exchange contracts		100,602		73,158
Interest rate contract		376,000		376,000