Income Taxes (Schedule of Components of Income from Continuing Operations) (Details) (USD $) In Thousands	3 Months Ended	12 Months Ended
Oct. 31, 2010	Jul. 31, 2010	Apr. 30, 2010	Jan. 31, 2010	Oct. 31, 2009	Jul. 31, 2009	Apr. 30, 2011	Apr. 30, 2010	Apr. 30, 2009
Income Taxes
Domestic							$ 639,914	$ 745,912	$ 815,614
Foreign							37,111	38,223	23,756
Income from continuing operations before income taxes	$ (175,119)	$ (207,317)	$ 1,110,410	$ 97,451	$ (212,853)	$ (210,873)	$ 677,025	$ 784,135	$ 839,370

The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 4
-Section 08
-Paragraph h
-Subparagraph 1(i)

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h)(1)(i))
-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

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The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile.

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Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

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