Goodwill And Intangible Assets (Schedule Of Inangible Assets And Goodwill) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Jan. 31, 2014	Apr. 30, 2013
Finite-Lived Intangible Assets [Line Items]
Goodwill, Gross carrying amount	$ 11,706	$ 11,706
Goodwill, Net carrying amount	11,706	11,706
Finite-lived intangible assets, Accumulated amortization	(7,576)	(6,422)
Finite-lived intangible assets, Net carrying amount	5,998
Intangible assets, Gross carrying amount	25,280	25,280
Intangible assets, Net carrying amount	17,704	18,858
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	(4,233)	(3,723)
Finite-lived intangible assets, Net carrying amount	2,003	2,513
Finite-lived intangible assets, Weighted-average useful life	7 years	7 years
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	(1,956)	(1,722)
Finite-lived intangible assets, Net carrying amount	682	916
Finite-lived intangible assets, Weighted-average useful life	5 years	5 years
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	(1,287)	(877)
Finite-lived intangible assets, Net carrying amount	3,313	3,723
Finite-lived intangible assets, Weighted-average useful life	10 years	10 years
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)
Finite-lived intangible assets, Weighted-average useful life	2 years	2 years