Intangible Assets Including Acquisition-Related Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013
Finite-Lived Intangible Assets [Line Items]
Beginning Balance	$ 687	$ 1,263
Amortization expense	(625)	(576)
Ending Balance	534	687
Taylor Manufacturing Systems, USA, LLC
Finite-Lived Intangible Assets [Line Items]
Intangibles related to the Taylor Manufacturing Systems, USA, LLC Acquisition	472
Supply Chain Management
Finite-Lived Intangible Assets [Line Items]
Beginning Balance	687	1,263
Amortization expense	(625)	(576)
Ending Balance	534	687
Supply Chain Management | Taylor Manufacturing Systems, USA, LLC
Finite-Lived Intangible Assets [Line Items]
Intangibles related to the Taylor Manufacturing Systems, USA, LLC Acquisition	$ 472