SMTC Corporation Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Details)

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017	Jan. 03, 2021	Nov. 08, 2018
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Total				$ 106,455
Operating Loss Carryforwards, Annual Limitation				3,909
Unrecognized Tax Benefits, Ending Balance	$ 0			0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	35.00%
Deferred Tax Asset, Decrease			$ 7,944
MC Assembly [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Total					$ 15,300
Domestic Tax Authority [Member] \| Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Total				80,884
Foreign Tax Authority [Member] \| Canada Revenue Agency [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Total				22,155
Foreign Tax Authority [Member] \| Asian Revenue Agency [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Total				3,416
Expires Between 2023 and 2027 [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Total				7,581
Expires Between 2028 And 2030 [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Total				31,239
Expires Between 2031 and 2036 [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Total				43,119
Expires Between 2037 and 2039 [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Total				19,972
Indefinite Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Total				$ 4,544