Debt (Details) (USD $)	3 Months Ended	12 Months Ended
Jan. 24, 2015	Jul. 26, 2014
Debt Instrument [Line Items]
Debt and capital lease obligations	$ 433,918,000us-gaap_DebtAndCapitalLeaseObligations	$ 457,801,000us-gaap_DebtAndCapitalLeaseObligations
Long-term debt premium on 7.125% senior subordinated notes (amortizes to interest expense through January 2021)	3,000,000	3,200,000
Senior Subordinated Notes \| 7.125% Senior Subordinated Notes Due 2021
Debt Instrument [Line Items]
Debt and capital lease obligations	277,500,000	277,500,000
Debt, interest rate (in percent)	7.125%	7.125%
Long-term debt premium on 7.125% senior subordinated notes (amortizes to interest expense through January 2021)	3,043,000	3,238,000
Long-term debt, fair value	288,900,000	297,600,000
Senior Credit Agreement - Term Loan (matures December 2017) \| Credit Agreement, December 3, 2012, Maturing December 2017
Debt Instrument [Line Items]
Debt and capital lease obligations	109,375,000	114,063,000
Revolving Credit Facility
Credit facility amount	125,000,000
Debt Instrument, Interest Rate at Period End	2.17%	2.15%
Senior Credit Agreement - Revolving facility (matures December 2017) \| Credit Agreement, December 3, 2012, Maturing December 2017
Debt Instrument [Line Items]
Debt and capital lease obligations	44,000,000	63,000,000
Revolving Credit Facility
Line of credit current borrowing capacity	275,000,000
Debt Instrument, Interest Rate at Period End	2.36%	2.55%
Unutilized commitment fee (in percent)	0.35%	0.35%
Additional borrowing availability	176,600,000	162,600,000
Senior Credit Agreement - Revolving facility (matures December 2017) \| Credit Agreement, December 3, 2012, Maturing December 2017 \| Standby Letters of Credit
Revolving Credit Facility
Line of credit current borrowing capacity	150,000,000
Letters of credit outstanding amount	54,400,000	49,400,000
Unutilized commitment fee (in percent)	2.00%	2.00%
Debt Premium \| 7.125% Senior Subordinated Notes Due 2021
Debt Instrument [Line Items]
Debt and capital lease obligations	$ 280,500,000	$ 280,700,000

Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.13,16)

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

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

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-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

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-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

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-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

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- Definition

The amount of debt premium that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

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Period Type:	instant

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
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- Details

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- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	credit
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- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

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