Employee Stock Ownership Plan (ESOP) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	6 Months Ended
Oct. 29, 2011	Oct. 30, 2010	Oct. 29, 2011 hours	Oct. 30, 2010
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Hours of service completed in order to be allocated shares of stock acquired by plan			1,000
Unallocated shares held by ESOP	4,473,987		4,473,987
Non cash portion of ESOP expense	$ 6,450	$ 525	$ 12,150	$ 1,050
1990 Note [Member]
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
ESOP company loan	$ 22,000		$ 22,000

Shares contributed to the ESOP that have not yet been released, committed to be released, or allocated to participant accounts. Suspense shares generally collateralize ESOP debt.

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

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 93-6

-Paragraph 53

-Subparagraph d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 40

-Section 50

-Paragraph 1

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6418621&loc=d3e17540-113929

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant