Intangible Assets (Schedule Of Intangible Assets And Goodwill) (Details) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2015	Apr. 30, 2014
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Gross carrying amount	$ 13,574	$ 13,574
Finite-lived intangible assets, Accumulated amortization	(9,095)	(7,960)
Finite-lived intangible assets, Net carrying amount	4,479us-gaap_FiniteLivedIntangibleAssetsNet	5,614us-gaap_FiniteLivedIntangibleAssetsNet
Customer-Related [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Gross carrying amount	6,236	6,236
Finite-lived intangible assets, Accumulated amortization	(4,913)	(4,403)
Finite-lived intangible assets, Net carrying amount	1,323	1,833
Technology-Based [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Gross carrying amount	2,638	2,638
Finite-lived intangible assets, Accumulated amortization	(2,268)	(2,034)
Finite-lived intangible assets, Net carrying amount	370	604
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Gross carrying amount	4,600	4,600
Finite-lived intangible assets, Accumulated amortization	(1,814)	(1,423)
Finite-lived intangible assets, Net carrying amount	2,786	3,177
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Gross carrying amount	100	100
Finite-lived intangible assets, Accumulated amortization	$ (100)	$ (100)

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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