Reconciliation of Segment Revenues and Operating Profit (Loss) to Consolidated (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jul. 31, 2012	Jul. 31, 2011
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net revenues	$ 16,685	$ 15,939
Operating profit (loss)	1,081	1,784
FEI-NY
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net revenues	11,848	10,615
Operating profit (loss)	1,122	1,890
Gillam-FEI
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net revenues	1,908	1,988
Operating profit (loss)	(116)	(230)
FEI-Zyfer
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net revenues	3,357	3,773
Operating profit (loss)	140	193
Inter Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net revenues	(428)	(437)
Corporate
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating profit (loss)	$ (65)	$ (69)