Commitments and Contingencies	3 Months Ended
Apr. 26, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	Commitments and Contingencies From time to time in the ordinary course of its business, the Company is involved in various claims, litigation, and other legal actions that are normal to the nature of its business, including with respect to intellectual property (“IP”), contract, product liability, employment, and environmental matters. In accordance with accounting standards regarding loss contingencies, the Company accrues an undiscounted liability for those contingencies where the incurrence of a loss is probable and the amount can be reasonably estimated. The Company also discloses the amount accrued and the amount of a reasonably possible loss in excess of the amount accrued, if such disclosure is necessary for its financial statements not to be misleading. The Company does not record liabilities when the likelihood that the liability has been incurred is probable but the amount cannot be reasonably estimated, or when the liability is believed to be only reasonably possible or remote. The Company evaluates, at least quarterly, developments in its legal matters that could affect the amount of liability that has been previously accrued, and makes adjustments as appropriate. Significant judgment is required to determine both probability and the estimated amount. The Company may be unable to estimate a possible loss or range of possible loss due to various reasons, including, among others: (i) if the damages sought are indeterminate; (ii) if the proceedings are in early stages, (iii) if there is uncertainty as to the outcome of pending appeals, motions or settlements, (iv) if there are significant factual issues to be determined or resolved, and (v) if there are novel or unsettled legal theories presented. In such instances, there is considerable uncertainty regarding the ultimate resolution of such matters, including a possible eventual loss, if any. Because litigation outcomes are inherently unpredictable, the Company’s evaluation of legal proceedings often involves a series of complex assessments by management about future events and can rely heavily on estimates and assumptions. While the consequences of certain unresolved proceedings are not presently determinable, and an estimate of the probable and reasonably possible loss or range of loss in excess of amounts accrued for such proceedings cannot be reasonably made, an adverse outcome from such proceedings could have a material adverse effect on the Company’s earnings in any given reporting period. However, in the opinion of management, after consulting with legal counsel, and taking into account insurance coverage, any ultimate liability related to current outstanding claims and lawsuits, individually or in the aggregate, is not expected to have a material adverse effect on the Company’s financial statements, as a whole. However, legal matters are inherently unpredictable and subject to significant uncertainties, some of which are beyond the Company’s control. As such, even though the Company intends to vigorously defend itself with respect to its legal matters, there can be no assurance that the final outcome of these matters will not materially and adversely affect the Company’s business, financial condition, results of operations, or cash flows. Environmental Matters In 2001, the Company was notified by the California Department of Toxic Substances Control (“State”) that it may have liability associated with the clean-up of the one-third acre Davis Chemical Company site in Los Angeles, California. The Company has been included in the clean-up program because it was one of the companies that used the Davis Chemical Company site for waste recycling and/or disposal between 1949 and 1990. The Company joined with other potentially responsible parties and entered into a Consent Order with the State that required the group to perform a soils investigation at the site and submit a remediation plan. The State has approved the remediation plan, which completes the group’s obligations under the Consent Order. Although the Consent Order does not require the group to remediate the site and the State has indicated it intends to look to other parties for remediation, the State has not yet issued “no further action” letters to the group members. To date, the Company’s share of the group’s expenses has not been material and has been expensed as incurred. The Company has used an environmental firm, specializing in hydrogeology, to perform monitoring of the groundwater at the Company’s former facility in Newbury Park, California that was leased for approximately forty years. The Company vacated the building in May 2002. Certain contaminants have been found in the local groundwater and site soils. The location of key soil contamination (and some related site groundwater impact associated with the soil contamination) is concentrated in and found to emanate from an area of an underground storage tank that the Company believes to have been installed and primarily used in the early 1960s by a former tenant at the site who preceded the Company’s tenancy. There are no litigation claims pending with respect to environmental matters at the Newbury Park site. The Los Angeles Regional Water Quality Control Board (“RWQCB”) having authority over the site issued joint instructions in November 2008, ordering the Company and the current owner of the site to perform additional assessments and surveys, and to create ongoing groundwater monitoring plans before any final regulatory action for “no further action” may be approved. In September 2009, the regulatory agency issued supplemental instructions to the Company and the current site owner regarding previously ordered site assessments, surveys and groundwater monitoring. In October 2013, an order was issued including a scope of proposed additional site work, monitoring, and proposed remediation activities. The Company filed appeals of the October 2013 order seeking reconsideration by the RWQCB and review by the State Water Resources Control Board (“SWRCB”) of the removal of two other potentially responsible parties, and seeking clarification of certain other factual findings. In April 2015, the RWQCB denied the Company’s request to name the two other potentially responsible parties to the order, but did correct certain findings of fact identified by the Company in its petition for reconsideration. The SWRCB has not yet ruled on the Company’s petition for review of the RWQCB’s action as the petition was filed with a request it be held in abeyance. The Company has been engaged with the regulatory agency, including technical discussion between the Company’s environmental firm and RWQCB staff, and has initiated the technical efforts to comply with the order. The Company submitted technical reports prepared by the environmental firm to the RWQCB and has received confirmation regarding the satisfaction of portions of the order. The Company also submitted a remedial action plan prepared by the environmental firm outlining the cleanup of soil, groundwater, and soil vapor at the site. The parties are continuing to work toward compliance with the October 2013 order and anticipate working cooperatively on any ultimate proposed cleanup and abatement work. The Company has accrued liabilities where it is probable that a loss will be incurred and the cost or amount of loss can be reasonably estimated. Based on the Company’s preliminary assessment following a November 2012 draft cleanup and abatement order, which has been reviewed under the October 2013 order pending the current appeal by the Company and other impacted parties, the Company had determined a likely range of probable loss between $2.7 million and $5.7 million. Based on recent determinations by the RWQCB and refinement of the draft remedial action plan, the Company has determined a likely range of probable loss between $4.8 million and $7.0 million. Given the uncertainties associated with environmental assessment and the remediation activities, the Company is unable to determine a best estimate within the range of loss. Therefore, the Company has recorded the minimum amount of $4.8 million, and such reserve remains on the Company’s books under “Other long-term liabilities” on the unaudited consolidated condensed balance sheets. These estimates could change as a result of changes in planned remedial actions, further actions from the regulatory agency, remediation technology, and other factors. Commercial Disputes In November 2012, the Company terminated the services of Intrigo Systems, Inc. (“Intrigo”) for default under its agreement with the Company for consulting services pertaining to the implementation of an enterprise resource planning (“ERP”) system. On January 23, 2013, the Company received a letter from Intrigo claiming that the Company breached the agreement and demanding payment of $2.6 million. The Company responded to this letter and denied liability for the claim, based on Intrigo’s failure to perform as required under the agreement. On November 13, 2014, Intrigo filed its complaint (the “Complaint”) against Semtech in Alameda County Superior Court, seeking in excess of $2.7 million in monetary damages and alleging breach of contract, breach of the covenant of good faith and fair dealing, and fraud. On December 18, 2014, the Company answered the Complaint and filed its own cross-complaint (the “Cross-Complaint”) against Intrigo, seeking in excess of $3.7 million in monetary damages and alleging breach of contract, breach of the implied covenant of good faith and fair dealing, fraud, negligent misrepresentation, false advertising, money had and received, and unfair competition. The Cross-Complaint also seeks a declaration that the Company’s contractual agreement with Intrigo was terminated and that the Company has no remaining obligations under any contract. Discovery is proceeding. At this time, the Company is unable to express an opinion on the outcome of this case. Indemnification The Company has entered into agreements with its current and former executives and directors indemnifying them against certain liabilities incurred in connection with the performance of their duties. The Company’s Certificate of Incorporation and Bylaws contain comparable indemnification obligations with respect to the Company’s current directors and employees. Product Warranties The Company’s general warranty policy provides for repair or replacement of defective parts. In some cases, a refund of the purchase price is offered. In certain instances the Company has agreed to other warranty terms, including some indemnification provisions. The product warranty accrual reflects the Company’s best estimate of probable liability under its product warranties. The Company accrues for known warranty issues if a loss is probable and can be reasonably estimated, and accrues for estimated incurred but unidentified issues based on historical experience. Historically, warranty expense has been immaterial to the Company’s consolidated financial statements. Earn-out Liability Pursuant to the terms of the amended earn-out arrangement (“Cycleo Amended Earn-out”) with the former stockholders of Cycleo SAS (“Cycleo Earn-out Beneficiaries”), which the Company acquired on March 7, 2012, the Company potentially may make payments totaling up to approximately $16.0 million based on the achievement of a combination of certain revenue and operating income milestones over a defined period (“Cycleo Defined Earn-out Period”). The Cycleo Defined Earn-out Period covers the period April 27, 2015 to April 26, 2020. For certain of the Cycleo Earn-out Beneficiaries, payment of the earn-out liability is contingent upon continued employment and is accounted for as post-acquisition compensation expense over the service period. The portion of the earn-out liability that is not dependent on continued employment is not considered as compensation expense. The Company has recorded a liability for the Cycleo Amended Earn-out of $2.7 million and $1.7 million as of April 26, 2015 and January 25, 2015, respectively. Pursuant to the terms of the Triune Earn-out with the former members of Triune (“Triune Earn-out Beneficiaries”), which the Company acquired on March 4, 2015, the Company potentially may make payments totaling up to approximately $70.0 million based on achievement of certain revenue targets measured at each fiscal year end, starting with fiscal year 2016 and ending in fiscal year 2018. An additional payment of up to $16.0 million may be made based upon a combination of cumulative revenue and operating income targets measured from the acquisition date through the end of the Company’s fiscal year 2018. For certain of the Triune Earn-out Beneficiaries, payment of the earn-out liability is contingent upon continued employment and is accounted for as post-acquisition compensation expense over the service period. The portion of the earn-out liability that is not dependent on continued employment is not considered as compensation expense. The Company has recorded a liability for the Triune Earn-out of $16.2 million, which represents the fair value as of April 26, 2015. This liability relates to the portion of the earn-out that is not dependent on continued employment. The Company will incur an additional $0.5 million of earn-out liability, subject to changes in fair value, through fiscal year 2018 that will be reported as compensation expense as the requisite services are provided.

Commitments and Contingencies

From time to time in the ordinary course of its business, the Company is involved in various claims, litigation, and other legal actions that are normal to the nature of its business, including with respect to intellectual property (“IP”), contract, product liability, employment, and environmental matters.

In accordance with accounting standards regarding loss contingencies, the Company accrues an undiscounted liability for those contingencies where the incurrence of a loss is probable and the amount can be reasonably estimated. The Company also discloses the amount accrued and the amount of a reasonably possible loss in excess of the amount accrued, if such disclosure is necessary for its financial statements not to be misleading. The Company does not record liabilities when the likelihood that the liability has been incurred is probable but the amount cannot be reasonably estimated, or when the liability is believed to be only reasonably possible or remote. The Company evaluates, at least quarterly, developments in its legal matters that could affect the amount of liability that has been previously accrued, and makes adjustments as appropriate. Significant judgment is required to determine both probability and the estimated amount. The Company may be unable to estimate a possible loss or range of possible loss due to various reasons, including, among others: (i) if the damages sought are indeterminate; (ii) if the proceedings are in early stages, (iii) if there is uncertainty as to the outcome of pending appeals, motions or settlements, (iv) if there are significant factual issues to be determined or resolved, and (v) if there are novel or unsettled legal theories presented. In such instances, there is considerable uncertainty regarding the ultimate resolution of such matters, including a possible eventual loss, if any.

Because litigation outcomes are inherently unpredictable, the Company’s evaluation of legal proceedings often involves a series of complex assessments by management about future events and can rely heavily on estimates and assumptions. While the consequences of certain unresolved proceedings are not presently determinable, and an estimate of the probable and reasonably possible loss or range of loss in excess of amounts accrued for such proceedings cannot be reasonably made, an adverse outcome from such proceedings could have a material adverse effect on the Company’s earnings in any given reporting period. However, in the opinion of management, after consulting with legal counsel, and taking into account insurance coverage, any ultimate liability related to current outstanding claims and lawsuits, individually or in the aggregate, is not expected to have a material adverse effect on the Company’s financial statements, as a whole. However, legal matters are inherently unpredictable and subject to significant uncertainties, some of which are beyond the Company’s control. As such, even though the Company intends to vigorously defend itself with respect to its legal matters, there can be no assurance that the final outcome of these matters will not materially and adversely affect the Company’s business, financial condition, results of operations, or cash flows.

Environmental Matters

In 2001, the Company was notified by the California Department of Toxic Substances Control (“State”) that it may have liability associated with the clean-up of the one-third acre Davis Chemical Company site in Los Angeles, California. The Company has been included in the clean-up program because it was one of the companies that used the Davis Chemical Company site for waste recycling and/or disposal between 1949 and 1990. The Company joined with other potentially responsible parties and entered into a Consent Order with the State that required the group to perform a soils investigation at the site and submit a remediation plan. The State has approved the remediation plan, which completes the group’s obligations under the Consent Order. Although the Consent Order does not require the group to remediate the site and the State has indicated it intends to look to other parties for remediation, the State has not yet issued “no further action” letters to the group members. To date, the Company’s share of the group’s expenses has not been material and has been expensed as incurred.

The Company has used an environmental firm, specializing in hydrogeology, to perform monitoring of the groundwater at the Company’s former facility in Newbury Park, California that was leased for approximately forty years. The Company vacated the building in May 2002. Certain contaminants have been found in the local groundwater and site soils. The location of key soil contamination (and some related site groundwater impact associated with the soil contamination) is concentrated in and found to emanate from an area of an underground storage tank that the Company believes to have been installed and primarily used in the early 1960s by a former tenant at the site who preceded the Company’s tenancy. There are no litigation claims pending with respect to environmental matters at the Newbury Park site.

The Los Angeles Regional Water Quality Control Board (“RWQCB”) having authority over the site issued joint instructions in November 2008, ordering the Company and the current owner of the site to perform additional assessments and surveys, and to create ongoing groundwater monitoring plans before any final regulatory action for “no further action” may be approved. In September 2009, the regulatory agency issued supplemental instructions to the Company and the current site owner regarding previously ordered site assessments, surveys and groundwater monitoring. In October 2013, an order was issued including a scope of proposed additional site work, monitoring, and proposed remediation activities. The Company filed appeals of the October 2013 order seeking reconsideration by the RWQCB and review by the State Water Resources Control Board (“SWRCB”) of the removal of two other potentially responsible parties, and seeking clarification of certain other factual findings. In April 2015, the RWQCB denied the Company’s request to name the two other potentially responsible parties to the order, but did correct certain findings of fact identified by the Company in its petition for reconsideration. The SWRCB has not yet ruled on the Company’s petition for review of the RWQCB’s action as the petition was filed with a request it be held in abeyance.

The Company has been engaged with the regulatory agency, including technical discussion between the Company’s environmental firm and RWQCB staff, and has initiated the technical efforts to comply with the order. The Company submitted technical reports prepared by the environmental firm to the RWQCB and has received confirmation regarding the satisfaction of portions of the order. The Company also submitted a remedial action plan prepared by the environmental firm outlining the cleanup of soil, groundwater, and soil vapor at the site. The parties are continuing to work toward compliance with the October 2013 order and anticipate working cooperatively on any ultimate proposed cleanup and abatement work.

The Company has accrued liabilities where it is probable that a loss will be incurred and the cost or amount of loss can be reasonably estimated. Based on the Company’s preliminary assessment following a November 2012 draft cleanup and abatement order, which has been reviewed under the October 2013 order pending the current appeal by the Company and other impacted parties, the Company had determined a likely range of probable loss between $2.7 million and $5.7 million. Based on recent determinations by the RWQCB and refinement of the draft remedial action plan, the Company has determined a likely range of probable loss between $4.8 million and $7.0 million. Given the uncertainties associated with environmental assessment and the remediation activities, the Company is unable to determine a best estimate within the range of loss. Therefore, the Company has recorded the minimum amount of $4.8 million, and such reserve remains on the Company’s books under “Other long-term liabilities” on the unaudited consolidated condensed balance sheets. These estimates could change as a result of changes in planned remedial actions, further actions from the regulatory agency, remediation technology, and other factors.

Commercial Disputes

In November 2012, the Company terminated the services of Intrigo Systems, Inc. (“Intrigo”) for default under its agreement with the Company for consulting services pertaining to the implementation of an enterprise resource planning (“ERP”) system. On January 23, 2013, the Company received a letter from Intrigo claiming that the Company breached the agreement and demanding payment of $2.6 million. The Company responded to this letter and denied liability for the claim, based on Intrigo’s failure to perform as required under the agreement. On November 13, 2014, Intrigo filed its complaint (the “Complaint”) against Semtech in Alameda County Superior Court, seeking in excess of $2.7 million in monetary damages and alleging breach of contract, breach of the covenant of good faith and fair dealing, and fraud. On December 18, 2014, the Company answered the Complaint and filed its own cross-complaint (the “Cross-Complaint”) against Intrigo, seeking in excess of $3.7 million in monetary damages and alleging breach of contract, breach of the implied covenant of good faith and fair dealing, fraud, negligent misrepresentation, false advertising, money had and received, and unfair competition. The Cross-Complaint also seeks a declaration that the Company’s contractual agreement with Intrigo was terminated and that the Company has no remaining obligations under any contract. Discovery is proceeding. At this time, the Company is unable to express an opinion on the outcome of this case.

Indemnification

The Company has entered into agreements with its current and former executives and directors indemnifying them against certain liabilities incurred in connection with the performance of their duties. The Company’s Certificate of Incorporation and Bylaws contain comparable indemnification obligations with respect to the Company’s current directors and employees.

Product Warranties

The Company’s general warranty policy provides for repair or replacement of defective parts. In some cases, a refund of the purchase price is offered. In certain instances the Company has agreed to other warranty terms, including some indemnification provisions.

The product warranty accrual reflects the Company’s best estimate of probable liability under its product warranties. The Company accrues for known warranty issues if a loss is probable and can be reasonably estimated, and accrues for estimated incurred but unidentified issues based on historical experience. Historically, warranty expense has been immaterial to the Company’s consolidated financial statements.

Earn-out Liability

Pursuant to the terms of the amended earn-out arrangement (“Cycleo Amended Earn-out”) with the former stockholders of Cycleo SAS (“Cycleo Earn-out Beneficiaries”), which the Company acquired on March 7, 2012, the Company potentially may make payments totaling up to approximately $16.0 million based on the achievement of a combination of certain revenue and operating income milestones over a defined period (“Cycleo Defined Earn-out Period”). The Cycleo Defined Earn-out Period covers the period April 27, 2015 to April 26, 2020. For certain of the Cycleo Earn-out Beneficiaries, payment of the earn-out liability is contingent upon continued employment and is accounted for as post-acquisition compensation expense over the service period. The portion of the earn-out liability that is not dependent on continued employment is not considered as compensation expense. The Company has recorded a liability for the Cycleo Amended Earn-out of $2.7 million and $1.7 million as of April 26, 2015 and January 25, 2015, respectively.

Pursuant to the terms of the Triune Earn-out with the former members of Triune (“Triune Earn-out Beneficiaries”), which the Company acquired on March 4, 2015, the Company potentially may make payments totaling up to approximately $70.0 million based on achievement of certain revenue targets measured at each fiscal year end, starting with fiscal year 2016 and ending in fiscal year 2018. An additional payment of up to $16.0 million may be made based upon a combination of cumulative revenue and operating income targets measured from the acquisition date through the end of the Company’s fiscal year 2018. For certain of the Triune Earn-out Beneficiaries, payment of the earn-out liability is contingent upon continued employment and is accounted for as post-acquisition compensation expense over the service period. The portion of the earn-out liability that is not dependent on continued employment is not considered as compensation expense. The Company has recorded a liability for the Triune Earn-out of $16.2 million, which represents the fair value as of April 26, 2015. This liability relates to the portion of the earn-out that is not dependent on continued employment. The Company will incur an additional $0.5 million of earn-out liability, subject to changes in fair value, through fiscal year 2018 that will be reported as compensation expense as the requisite services are provided.