Net Income Per Share - Narrative (Detail) - shares	12 Months Ended
Apr. 27, 2014	Apr. 28, 2013	May. 03, 2015	Apr. 29, 2012
Earnings Per Share Disclosure [Line Items]
Number of shares of common stock excluded from the computation of basic net income	61,668	123,335
Time Vested Restricted Stock Awards [Member]
Earnings Per Share Disclosure [Line Items]
Number of shares outstanding and unvested	61,668	123,335	0	185,000

Number of shares of restricted stock determined by relating the portion of time within a reporting period that restricted shares have been outstanding to the total time in that period. Restricted shares are subject to sales, contractual, regulatory or other restrictions that prevent or inhibit the holder from freely disposing of them before the restriction ends.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 45

-Paragraph 13

-URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e2646-109256

Name:	us-gaap_WeightedAverageNumberOfSharesRestrictedStock
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration