Intangible Assets (Schedule Of Intangible Assets And Goodwill) (Details) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Gross carrying amount	$ 13,574	$ 13,574
Finite-lived intangible assets, Accumulated amortization	(7,960)	(6,422)
Finite-lived intangible assets, Net carrying amount	5,614	7,152
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	(4,403)	(3,723)
Finite-lived intangible assets, Net carrying amount	1,833	2,513
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	(2,034)	(1,722)
Finite-lived intangible assets, Net carrying amount	604	916
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	(1,423)	(877)
Finite-lived intangible assets, Net carrying amount	3,177	3,723
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)