Income Taxes (Schedule Of Components Of Income From Continuing Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Income Tax Disclosure [Abstract]
Domestic									$ 664,966	$ 547,535	$ 590,024
Foreign									37,045	28,535	37,679
Income from continuing operations before income taxes	$ 1,129,836	$ (96,268)	$ (162,288)	$ (169,269)	$ 981,626	$ (1,026)	$ (203,929)	$ (200,601)	$ 702,011	$ 576,070	$ 627,703

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 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

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Subparagraph 1(i)

-Article 4

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- Definition

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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- Definition

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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