Property, Plant, and Equipment (Detail) (USD $) In Thousands, unless otherwise specified									12 Months Ended
	Apr. 28, 2013	Jan. 27, 2013	Oct. 28, 2012	Jul. 29, 2012	Apr. 29, 2012	Jan. 29, 2012	Oct. 30, 2011	Jul. 31, 2011	Apr. 28, 2013 land and improvements [Member] Minimum [Member]	Apr. 28, 2013 land and improvements [Member] Maximum [Member]	Apr. 28, 2013 buildings and improvements [Member] Minimum [Member]	Apr. 28, 2013 buildings and improvements [Member] Maximum [Member]	Apr. 28, 2013 leasehold improvements [Member]		Apr. 28, 2013 machinery and equipment [Member] Minimum [Member]	Apr. 28, 2013 machinery and equipment [Member] Maximum [Member]	Apr. 28, 2013 office furniture and equipment [Member] Minimum [Member]	Apr. 28, 2013 office furniture and equipment [Member] Maximum [Member]
Property, Plant and Equipment [Line Items]
depreciable lives									0 years	10 years	7 years	40 years		[1]	3 years	12 years	3 years	10 years
land and improvements	$ 741				$ 741
buildings and improvements	12,812				12,566
leasehold improvements	801				801
machinery and equipment	53,608				51,267
office furniture and equipment	6,587				5,869
capital projects in progress	1,733				1,062
property, plant and equipment, gross	76,282				72,306
accumulated depreciation and amortization	(45,688)				(41,027)
property, plant and equipment, net	$ 30,594	$ 30,055	$ 30,621	$ 31,016	$ 31,279	$ 30,285	$ 30,431	$ 30,615

[1] Shorter of life of lease or useful life.