Derivative Financial Instruments (Narrative) (Details) (USD $) In Millions	3 Months Ended
Jul. 30, 2011 Interest Rate Caps Maturing September 2018 [Member]	Jul. 30, 2011 Interest Rate Swap Agreement Maturing July 2015 [Member]	Jul. 30, 2011 Interest Rate Swap Agreement Maturing November 2011 [Member]	Jul. 30, 2011 Interest Rate Swap Agreement Maturing February 2012 [Member]	Jul. 31, 2010 Foreign Currency Contracts [Member]
Notional amount of derivatives	$ 500	$ 110	$ 4	$ 3
Maturity date	Sep. 01, 2018	Jul. 01, 2015	Nov. 01, 2011	Feb. 01, 2012
Gain on derivative					$ 0.1

Aggregate notional amount of all derivatives. The notional amount relates to a number of currency units, shares, bushels, pounds, or other units specified in a derivative instrument.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Notional Amount
-URI http://asc.fasb.org/extlink&oid=6519104

Name:	us-gaap_NotionalAmountOfDerivatives
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant