Stock-Based Awards (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended	9 Months Ended
Apr. 26, 2014	Apr. 26, 2014	Jul. 27, 2013
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to stock options	$ 4.2	$ 4.2
Total compensation cost not yet recognized, period for recognition	2 years 2 months 12 days
Restricted Share Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to RSUs	7.2	7.2
Total compensation cost not yet recognized, period for recognition	2 years 9 months 18 days
Granted		94,456
RSUs outstanding	414,597	414,597	463,318
Performance Restricted Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to RSUs	12.9	12.9
Total compensation cost not yet recognized, period for recognition	1 year 7 months 6 days
Compensation expense	$ 9.7	$ 9.7
Granted		429,485
Forfeited or cancelled		265,000
RSUs outstanding	1,197,603	1,197,603	1,315,138
Performance Restricted Share Units \| Target Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted		373,465
RSUs outstanding	754,752	754,752
Performance Restricted Share Units \| Supplemental Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted		56,020
RSUs outstanding	442,851	442,851

Potential Compensation Expense for Performance Based Shares If Performance Goals Are Met

No definition available.

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Cancelled in Period

+ References

No definition available.

+ Details

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

+ References

No definition available.

+ Details

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- Definition

Unrecognized cost of unvested options awarded to employees as compensation.

+ References

No definition available.

+ Details

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(i)-(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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