Employee Stock Ownership Plan (ESOP) (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
Jul. 30, 2011 hours	Jul. 31, 2010
ESOP shares of stock allocated per hours of service during the year	1,000
Unallocated shares held by ESOP	3,629,662
ESOP compensation	$ 5,700	$ 525
1990 Note [Member]
ESOP company loan	$ 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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

Name:	us-gaap_EmployeeStockOwnershipPlanESOPNumberOfSuspenseShares
Namespace Prefix:	us-gaap
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant