Commitments and Contingencies (Schedule Of Future Minimum Rental Payments Under Operating Leases) (Details) (USD $)	12 Months Ended
Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011
Commitments and Contingencies Disclosure [Abstract]
2014	$ 1,543,000
2015	953,000
2016	980,000
2017	563,000
Total	4,039,000
Rent expense	$ 1,500,000	$ 1,600,000	$ 1,600,000

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Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 122

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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-Name Accounting Standards Codification

-Topic 840

-SubTopic 10

-Section 55

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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Amount of required minimum rental payments maturing in the forth rolling twelve months following the latest balance sheet presented for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References

No definition available.

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Amount of required minimum rental payments maturing in the third rolling twelve months following the latest balance sheet presented for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References

No definition available.

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Amount of required minimum rental payments maturing in the second rolling twelve months following the latest balance sheet presented for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

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No definition available.

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Amount of required minimum rental payments maturing in the next rolling twelve months following the latest balance sheet presented for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

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Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

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