Derivative Instruments and Hedging Activities, Estimated Fair Values of Derivative Instruments (Details) - Interest Rate Swap [Member] - USD ($) $ in Thousands	Jul. 29, 2016	Jul. 31, 2015
Derivatives, Fair Value [Line Items]
Fair value, asset	$ 0	$ 3,759
Fair value, liability	22,250	9,821
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value, asset	0	3,759
Current Interest Rate Swap Liability [Member]
Derivatives, Fair Value [Line Items]
Fair value, liability	180	1,117
Long-term Interest Rate Swap Liability [Member]
Derivatives, Fair Value [Line Items]
Fair value, liability	$ 22,070	$ 8,704

Fair value, after offset of derivative asset, of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=d3e41678-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=51825145&loc=SL20226006-175313

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=51825145&loc=SL20226008-175313

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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