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Business Acquisitions - Schedule of Unaudited Proforma Combined Information (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Business Acquisition [Line Items]
Revenue	$ 465,083	$ 487,707
Operating income (loss)	13,118	(9,670)
Net loss attributable to common stockholders	$ (54,440)	$ (78,230)
Basic and diluted loss per common share attributable to common stockholders	$ (1.60)	$ (2.92)
Basic and diluted weighted average shares outstanding	34,015	26,749	26,105

X

- Definition

The pro forma basic and diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

No definition available.

+ Details

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- Definition

The pro forma operating income for the period as if the business combination or combinations had been completed at the beginning of the period.

+ References

No definition available.

+ Details

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- Details

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- Definition

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=7659399&loc=d3e1392-128463

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- Definition

The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=7659399&loc=d3e1392-128463

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- Definition

Average number of shares or units issued and outstanding that are used in calculating basic and diluted earnings per share (EPS).

+ References

No definition available.

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