Restructuring Costs - Restructuring Reserve Rollforward (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Jan. 25, 2015	Jan. 26, 2014	Jan. 27, 2013
Restructuring Reserve [Roll Forward]
Beginning balance	$ 2,632us-gaap_RestructuringReserve	$ 0us-gaap_RestructuringReserve
Restructuring charges	1,285us-gaap_RestructuringCharges	3,086us-gaap_RestructuringCharges	0us-gaap_RestructuringCharges
Cash payments	3,520us-gaap_PaymentsForRestructuring	454us-gaap_PaymentsForRestructuring
Ending balance	282us-gaap_RestructuringReserve	2,632us-gaap_RestructuringReserve	0us-gaap_RestructuringReserve
Restructuring Reserve, Translation and Other Adjustment	(115)
One-time employee termination benefits
Restructuring Reserve [Roll Forward]
Beginning balance	1,387	0
Restructuring charges	662	1,841
Cash payments	(1,767)	(454)
Ending balance	282	1,387
Restructuring Reserve, Translation and Other Adjustment	0
Contract commitments
Restructuring Reserve [Roll Forward]
Beginning balance	1,245	0
Restructuring charges	623	1,245
Cash payments	1,753	0
Ending balance	0	1,245
Restructuring Reserve, Translation and Other Adjustment	$ (115)

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

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- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 5.P.4(b))

-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

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-Section S99

-Paragraph 1

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-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140864-122747

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section P

-Subsection 3, 4

+ Details

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- Definition

Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 5.P.4(b))

-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

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-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section P

-Subsection 3, 4

+ Details

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- Definition

The amount of change in the restructuring reserve related to foreign currency translation adjustments and any other adjustments not separately disclosed or provided for elsewhere in the Taxonomy.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 5.P.4(b)(2))

-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)(2)

-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

+ Details

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