Restructuring (Details Textual) (USD $)	12 Months Ended
Apr. 30, 2011 PositionsEliminated Facilities RetailMarketSegment UnionContract Votes Plants	Apr. 30, 2010	Apr. 30, 2009
Restructuring (Textuals) [Abstract]
Expected restructuring costs - March 2010 announcement	$ 190,000,000
Expected restructuring costs - September 2010 announcement	45,000,000
Total expected restructuring charge	235,000,000
Restructuring costs incurred announcement-to-date	107,700,000
Total restructuring charges	101,957,000	5,711,000
Reduction in position due to restructuring	850
Cost of products sold restructuring	54,089,000	3,870,000	0
Plants announced to be closed	6
Years over which balance of restructuring costs will be incurred	3
Approximate total restructuring costs related to the Company's divested Canadian businesses	47,868,000	1,841,000	10,229,000
Other noncash restructuring charges	$ 8,540,000	$ 0	$ 9,093,000

Amounts charged against earnings in the period for incurred and estimated costs, primarily related to long-lived asset, production start-up and inventory-related charges, associated with exit from or disposal of business activities or restructurings pursuant to a program that is planned and controlled by management, and materially changes either the scope of a business undertaken by an entity, or the manner in which that business is conducted.

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- Definition

Noncash portion of amount charged against earnings in the period for incurred and estimated costs, excluding depreciation charges and asset retirement obligations, associated with exit from or disposal of business activities or restructurings pursuant to a program that is planned and controlled by management, and materially changes either the scope of a business undertaken by an entity, or the manner in which that business is conducted.

+ Details

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- Definition

The charge against earnings in the period, comprised of costs associated with restructuring activities pursuant to a duly authorized plan, excluding a discontinued operation as defined by generally accepted accounting principles. Costs of such activities include those for one-time termination benefits, severance costs associated with established compensation plans, termination of contracts, consolidating or closing facilities, and relocating employees.

+ Details

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- Definition

Plants announced to be closed upon completion of the restructurings.

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- Definition

The expected number of positions to be eliminated as a result of restructuring activities.

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Restructuring Textuals Abstract.

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Amount expected to be charged against earnings in the current and future periods for the specified restructuring costs, as estimated at the balance sheet date.

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- Definition

Amount expected to be charged against earnings in the current and future periods for restructuring costs associated with the plans announced in March 2010, as estimated at the balance sheet date.

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Amount expected to be charged against earnings in the current and future periods for restructuring costs associated with the plans announced in September 2010, as estimated at the balance sheet date.

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- Definition

Expected years over which the balance to the restructuring costs are expected to be charged against earnings, as estimated at balance sheet date.

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Amount of costs incurred to date for the specified type of restructuring cost.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 146
-Paragraph 20

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Emerging Issues Task Force (EITF)
-Number 95-3

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 5
-Section P
-Subsection 3, 4

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Reserve increase representing the amount charged against earnings in the period for a specified incurred and estimated type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 146

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