Investments And Restricted Investments (Narrative) (Details) (USD $) In Millions	Jul. 30, 2011
Underlying assets in non-qualified deferred compensation program	$ 69.0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Underlying assets in non-qualified deferred compensation program	59.3
Significant Other Observable Inputs (Level 2) [Member]
Underlying assets in non-qualified deferred compensation program	$ 9.7

Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 17
-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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