Accounts Receivable (Detail) (USD $) In Thousands, unless otherwise specified	Oct. 27, 2013	Apr. 28, 2013		Oct. 28, 2012	Apr. 29, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Customers	$ 26,022	$ 24,715		$ 21,790
Accounts receivable, net	24,937	23,392	[1]	20,678
Allowance for doubtful accounts [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Valuation allowance, balance	(513)	(780)		(559)	(567)
Reserve for returns and allowances and discounts [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Valuation allowance, balance	$ (572)	$ (543)		$ (553)	$ (478)

[1] Derived from audited financial statements.