Geographic Information And Concentrations Of Risk (Concentration Risk Of Net Sales) (Details)	12 Months Ended
Jan. 29, 2012	Jan. 30, 2011	Jan. 31, 2010
Samsung Electronics (And Affiliates) [Member]
Geographic Information And Concentration Of Risk [Line Items]
Concentration of risk	13.00%	12.00%	17.00%
Frontek Technology Corp [Member]
Geographic Information And Concentration Of Risk [Line Items]
Concentration of risk	10.00%	11.00%	13.00%

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 year-to-date concentration percentage derived from the division.

No definition available.

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