Income Taxes - Allocation of Income Tax Expense (Benefit) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	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	Apr. 29, 2012	May 01, 2011
Income Taxes [Line Items]
income from operations	$ 2,161	$ 1,700	$ (3,736)	$ 1,848	$ 2,071	$ 1,075	$ (3,389)	$ 1,145	$ 1,972	$ 902	$ (1,102)
shareholders' equity, related to the tax benefit arising from the exercise of stock options									(76)	(64)	(339)
income tax expense (benefit), excluding tax benefit from exercise of stock options									$ 1,896	$ 838	$ (1,441)

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Article 4

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Income Tax Expense (or Benefit)

-URI http://asc.fasb.org/extlink&oid=6515339

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (a),(b)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration