Allocated share-based compensation expense as a percentage of net revenue

No definition available.

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

- Definition

Revenue Offset

+ References

No definition available.

+ Details

Name:	smtc_RevenueOffset
Namespace Prefix:	smtc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13531-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13537-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

+ Details

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

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

+ Details

Name:	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	srt_ProductOrServiceAxis=smtc_SignalIntegrityandTimingProductsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=smtc_ProtectionProductsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=smtc_WirelessandSensingProductsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=smtc_WarrantSharesMember
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:

Segment Information - Revenue by Product Line (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 26, 2020	Oct. 27, 2019	Jul. 28, 2019	Apr. 28, 2019	Jan. 27, 2019	Oct. 28, 2018	Jul. 29, 2018	Apr. 29, 2018	Jan. 26, 2020	Jan. 27, 2019	Jan. 28, 2018
Revenue from External Customer [Line Items]
Net sales	$ 138,001	$ 141,011	$ 137,146	$ 131,354	$ 160,006	$ 173,550	$ 163,211	$ 130,429	$ 547,512	$ 627,196	$ 587,847
Signal Integrity [Member]
Revenue from External Customer [Line Items]
Net sales									222,846	276,040	263,015
Protection
Revenue from External Customer [Line Items]
Net sales									157,212	182,068	176,482
Wireless and Sensing [Member]
Revenue from External Customer [Line Items]
Net sales									167,454	190,589	164,569
Other: Warrant Shares
Revenue from External Customer [Line Items]
Net sales offset									$ 0	$ (21,501)	$ (16,219)
Net sales revenue
Revenue from External Customer [Line Items]
Concentration risk, percentage									100.00%	100.00%	100.00%
Net sales revenue \| Signal Integrity [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage									40.00%	44.00%	45.00%
Net sales revenue \| Protection
Revenue from External Customer [Line Items]
Concentration risk, percentage									29.00%	29.00%	30.00%
Net sales revenue \| Wireless and Sensing [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage									31.00%	30.00%	28.00%
Net sales revenue \| Other: Warrant Shares
Revenue from External Customer [Line Items]
Allocated share-based compensation expense as a percentage of net revenue									0.00%	(3.00%)	(3.00%)