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Stockholders' (Deficit) Equity - Summary of Restricted Stock, Restricted Stock Unit and Performance Stock Unit Activity (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Schedule Of Restricted Stock Restricted Stock Unit And Performance Stock Unit Activity [Line Items]
Restricted Stock, Restricted Stock Units, and Performance Stock Units Outstanding, April 30, 2013	431	62
Restricted Stock, Restricted Stock Units, and Performance Stock Units, Granted	542	735	611
Restricted Stock, Restricted Stock Units, and Performance Stock Units Outstanding, April 30, 2014	454	431	62
Weighted Average Grant Price, Outstanding, April 30, 2013	$ 5.28
Weighted Average Grant Price, Granted	$ 4.28
Weighted Average Grant Price, Forfeited	$ 5.86
Weighted Average Grant Price, Outstanding, April 30, 2014	$ 4.77	$ 5.28
Weighted Average Grant Price, Expected to vest, April 30, 2014	$ 4.82
Weighted Average Remaining Contractual Term Outstanding	1 year 6 months
Weighted Average Remaining Contractual Term Expected to vest	1 year 6 months
Aggregate Intrinsic Value, Outstanding, April 30, 2014	$ 500
Aggregate Intrinsic Value, Expected to vest, April 30, 2014	$ 409
Restricted Stock, Restricted Stock Units and Performance Stock Units [Member]
Schedule Of Restricted Stock Restricted Stock Unit And Performance Stock Unit Activity [Line Items]
Restricted Stock, Restricted Stock Units, and Performance Stock Units Outstanding, April 30, 2013	1,088
Restricted Stock, Restricted Stock Units, and Performance Stock Units, Granted	542
Restricted Stock, Restricted Stock Units, and Performance Stock Units, Forfeited	(226)
Restricted Stock, Restricted Stock Units, and Performance Stock Units Outstanding, April 30, 2014	1,077
Restricted Stock, Restricted Stock Units, and Performance Stock Units, Expected to vest, April 30, 2014	947
Class A Common Stock [Member]
Schedule Of Restricted Stock Restricted Stock Unit And Performance Stock Unit Activity [Line Items]
Weighted Average Grant Price Common Stock, Vested	$ 4.89
Class A Common Stock [Member] | Restricted Stock, Restricted Stock Units and Performance Stock Units [Member]
Schedule Of Restricted Stock Restricted Stock Unit And Performance Stock Unit Activity [Line Items]
Restricted Stock, Restricted Stock Units, and Performance Stock Units Common Stock, Vested	(327)

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Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Expected To Vest Aggregate Intrinsic Value

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Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Expected To Vest Number

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Intrinsic value of equity-based compensation awards outstanding. Excludes stock and unit options.

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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