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Stockholders' Equity - Summary of Stock Options, Restricted Stock and Restricted / Performance Stock Units Outstanding (Parenthetical) (Detail) (USD $) | 12 Months Ended
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Apr. 30, 2013
Schedule Of Stock Option Activity [Line Items] |
Number of shares to be vested | 125
Fair value of the stock options vested and outstanding | $ 378
Performance Stock Units [Member] |
Schedule Of Stock Option Activity [Line Items] |
Performance stock units, percentage of attainment level | 100.00%
Class A Common Stock [Member] |
Schedule Of Stock Option Activity [Line Items] |
Common stock additional issue | 357

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- Details
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- Definition The attainment level for performance stock units included in the roll forward. + References No definition available. + Details
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- Definition As of the balance sheet date, the number of shares into which fully vested and expected to vest stock options outstanding can be converted under the option plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 123R -Paragraph A240 -Subparagraph d(1) -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
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- Definition Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock. + References No definition available. + Details
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