Derivative Financial Instruments (Fair Value Of The Company's Interest Rate Contracts) (Details) (USD $) In Millions	Jul. 30, 2011	Apr. 30, 2011	Jul. 31, 2010
Other Noncurrent Assets [Member]
Interest rate contracts, fair value	$ 3.1	$ 5.5	$ 4.9
Other Noncurrent Liabilities [Member]
Interest rate contracts, fair value	$ 3.1	$ 5.6	$ 5.5

Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 10
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6947722&loc=d3e13433-108611

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant