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://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=84177426&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=77997519&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=84177426&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=77997519&loc=d3e13537-108611

+ 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

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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

- Details

Name:	us-gaap_ProductOrServiceAxis=smtc_SignalIntegrityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=smtc_ProtectionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=smtc_WirelessandSensingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=smtc_OtherWarrantSharesMember
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 ($)	3 Months Ended		9 Months Ended
	Oct. 28, 2018	Oct. 29, 2017	Oct. 28, 2018	Oct. 29, 2017
Revenue from External Customer [Line Items]
Net sales	$ 173,550,000	$ 150,304,000	$ 467,190,000	$ 447,233,000
Signal Integrity [Member]
Revenue from External Customer [Line Items]
Net sales	69,981,000	63,921,000	204,381,000	198,645,000
Protection [Member]
Revenue from External Customer [Line Items]
Net sales	53,085,000	49,366,000	139,875,000	136,673,000
Wireless and Sensing [Member]
Revenue from External Customer [Line Items]
Net sales	50,484,000	43,266,000	144,435,000	126,641,000
Other: Warrant Shares
Revenue from External Customer [Line Items]
Net sales offset	$ 0	$ (6,249,000)	$ (21,501,000)	$ (14,726,000)
Net sales [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage	100.00%	100.00%	100.00%	100.00%
Net sales [Member] \| Signal Integrity [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage	40.00%	42.00%	44.00%	43.00%
Net sales [Member] \| Protection [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage	31.00%	33.00%	30.00%	31.00%
Net sales [Member] \| Wireless and Sensing [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage	29.00%	29.00%	31.00%	29.00%
Net sales [Member] \| Other: Warrant Shares
Revenue from External Customer [Line Items]
Concentration risk, percentage	(0.00%)	(4.00%)	(5.00%)	(3.00%)