Components of Loss from Continuing Operations Before Income Tax (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
Jan. 31, 2013	Jan. 31, 2012	Apr. 30, 2012	Apr. 30, 2011	Apr. 30, 2010
Schedule of Components of Income Before Income Tax Expense (Benefit) [Line Items]
Luxembourg			$ (38,499)	$ 5,411	$ 61,930
Foreign			7,823	(100,394)	(127,699)
Income (loss) from continuing operations before income tax	$ (37,699)	$ (39,670)	$ (30,676)	$ (94,983)	$ (65,769)

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

+ References

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

+ Details

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- Definition

This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 10

-Article 5

+ Details

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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.

+ References

+ Details

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