Concentration Risk, Minimum Concentration Risk Threshold, Percentage

No definition available.

Name:	smtc_ConcentrationRiskMinimumConcentrationRiskThresholdPercentage
Namespace Prefix:	smtc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Number Of Customers Accounting For At Least Ten Percent Of Net Receivables

+ References

No definition available.

+ Details

Name:	smtc_NumberOfCustomersAccountingForAtLeastTenPercentOfNetReceivables
Namespace Prefix:	smtc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Description of risks that arise due to concentrations of operating facilities, revenues, assets, customers, vendors or the like in a certain geographic area, either domestic or foreign. The description may address risks inherent in the geographic area, and, at a minimum, informs users of the general nature of the risk, but excludes "Information about Geographic Areas" that may be disclosed elsewhere (for instance, segment disclosures)..

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6404-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6351-108592

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6327-108592

+ Details

Name:	us-gaap_ConcentrationRiskGeographic
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ConcentrationRiskLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13531-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6404-108592

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13537-108611

+ Details

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_AccountsReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueNetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=smtc_DistributorConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=country_CN
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=smtc_CostofSiliconWafersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_SupplierConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Concentration of Risk - Narrative (Details) - Customers	3 Months Ended		9 Months Ended		12 Months Ended
Concentration of Risk - Narrative (Details) - Customers	Oct. 29, 2017	Oct. 30, 2016	Oct. 29, 2017	Oct. 30, 2016	Jan. 29, 2017
Concentration Risk [Line Items]
Number of customers accounting for at least 10% of total net receivables	0		0		0
Description of geographic concentration risk related to distributors	For the third quarter of fiscal year 2018, our two largest distributors were based in Asia.
Accounts Receivable [Member]
Concentration Risk [Line Items]
Minimum concentration risk threshold	10.00%				10.00%
Net sales [Member]
Concentration Risk [Line Items]
Minimum concentration risk threshold	10.00%		10.00%
Concentration risk, percentage	100.00%	100.00%	100.00%	100.00%
Net sales [Member] \| Distributor concentration risk [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	66.00%	64.00%
China \| Cost of Silicon Wafers [Member] \| Supplier concentration risk [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	21.00%	24.00%