Goodwill and Intangible Assets - Schedule of Additions to Finite-Lived Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Jan. 25, 2015	Jan. 26, 2014
Finite-lived Intangible Assets [Roll Forward]
Beginning gross carrying amount	$ 185,997	$ 228,618
Purchased intangible assets	1,100smtc_Purchasedintangibleassets	833smtc_Purchasedintangibleassets
Acquired intangible assets	1,430
Reduction of finite-lived intangible assets		(501)
Transfers from in-process research and development		25,100
Decrease in gross carrying value of due to impairment of finite-lived intangible a	(19,479)	(68,053)
Ending gross carrying value	$ 169,048	$ 185,997

Decrease in Gross Carrying Value Finite-lived Intangible Asset Due to Impairment

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- Definition

Finite-lived intangible assets, other change in gross carrying value

+ References

No definition available.

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- Definition

Finite-lived Intangible Assets, Period Increase due to Transfer from Indefinite-lived Intangible Assets

+ References

No definition available.

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- Definition

Purchased intangible assets

+ References

No definition available.

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- Definition

Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, resulting from a business combination.

+ References

No definition available.

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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