Preferred Stock (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Feb. 28, 2023	Dec. 31, 2022	Jan. 01, 2022	Jan. 02, 2021	Feb. 22, 2021	Apr. 24, 2020	Oct. 07, 2016
Temporary Equity [Line Items]
Dividends, Preferred Stock, Paid-in-kind		$ 0	$ 0	$ 3,881
Preferred stock accretion to redemption value		673	720	1,692
Series A Preferred Stock [Member] | Oaktree Organics, L.P. and Oaktree Huntington Investment Fund II, L.P.
Temporary Equity [Line Items]
Number of share issue for conversion preferred stock					12,633,427
Preferred Stock, Shares Issued							85,000
Preferred Stock, Value, Issued					$ 87,500		$ 85,000
Preferred stock, conversion price					$ 7
Preferred Stock Issuance Costs					$ 300
Series B-1 Preferred Stock [Member] | Stock issued to each recipient [Member]
Temporary Equity [Line Items]
Preferred Stock, Shares Issued	15,000					15,000
Series B-1 Preferred Stock [Member] | Engaged Capital [Member] | Subsequent Event [Member]
Temporary Equity [Line Items]
Preferred Stock, Dividend Rate, Percentage	8.00%
Series B-1 Preferred Stock [Member] | Oaktree and Engaged [Member]
Temporary Equity [Line Items]
Preferred Stock, Shares Issued						30,000
Preferred Stock, Value, Issued						$ 30,000
Preferred Stock Issuance Costs						$ 4,000
Payment of cash dividends		600
Dividends, Preferred Stock, Paid-in-kind		$ 400
Preferred Stock, Liquidation Preference Per Share		$ 1,015				$ 1,000
Preferred Stock, Liquidation Preference, Value		$ 30,400
Preferred Stock, Dividend Payment Terms		Cumulative preferred dividends accrue daily on the Series B-1 Preferred Stock at an annualized rate of 8.0% of the Series B-1 Liquidation Preference prior to September 30, 2029, and 10.0% of the liquidation preference thereafter (subject to an increase of 1.0% per quarter, up to a maximum rate of 5.0% per quarter on the occurrence of certain events of non-compliance).
Accrued Unpaid Dividends		$ 600
Preferred stock accretion to redemption value		$ 700	$ 500	$ 300
Preferred Stock, Convertible, Terms		At any time, the Series B-1 Preferred Stock may be exchanged, in whole or in part, into the number of Common Shares equal to, per share of Series B-1 Preferred Stock, the quotient of the Series B Liquidation Preference divided by $2.50 (such price, the "Series B-1 Exchange Price" and such quotient, the "Series B-1 Exchange Rate").
Convertible Preferred Stock, Settlement Terms		SunOpta Foods may cause the holders of the Series B-1 Preferred Stock to exchange all of their shares of Series B-1 Preferred Stock into a number of Common Shares equal to the number of shares of Series B-1 Preferred Stock outstanding multiplied by the Series B-1 Exchange Rate if (i) fewer than 10% of the shares of Series B-1 Preferred Stock issued on April 24, 2020 remain outstanding, or (ii) on or after April 24, 2023, the volume-weighted average price of the Common Shares during the then preceding 20 trading day period is greater than 200% of the Series B-1 Exchange Price then in effect.
Maximum holder beneficial ownership		19.99%
Preferred stock, convertible shares issuable		12,178,667
Preferred stock exchange, description of exchange price		The Series B-1 Exchange Price is subject to certain anti-dilution adjustments, including a weighted-average adjustment for issuances of Common Shares below the Series B-1 Exchange Price, provided that the Series B-1 Exchange Price may not be lower than $2.00 (subject to adjustment in cer
Series B Preferred Stock [Member] | Oaktree and Engaged [Member]
Temporary Equity [Line Items]
Preferred Stock, Convertible, Terms		Oaktree and Engaged Capital are entitled to vote the Series B-1 Preferred Stock with the Common Shares on an as-exchanged basis, subject to a permanent 19.99% voting cap. As a result of the voting cap, each of Oaktree and Engaged Capital will only be able to vote its Series B-1 Preferred Stock to the extent that, when taken together with any other voting securities each investor controls, such votes do not exceed 19.99% of the votes eligible to be cast by all security holders of the Company. On April 24, 2020, the Company designated Special Shares, Series 2 to serve as the mechanism for attaching exchanged voting rights to the Series B-1 Preferred Stock. The Special Shares, Series 2 entitle the holder thereof to one vote per Special Share, Series 2 on all matters submitted to a vote of the holders of Common Shares, voting together as a single class, subject to certain exceptions. The Special Shares, Series 2 are not transferrable and the voting rights associated with the Special Shares, Series 2 will terminate upon the transfer of the shares of Series B-1 Preferred Stock to a third party, other than an affiliate of Oaktree or Engaged Capital, as applicable. As at December 31, 2022, 6,089,333 Special Shares, Series 2 were issued to Engaged Capital, equal to the number of Common Shares issuable to Engaged Capital on the exchange of all of the shares of Series B-1 Preferred Stock held by it, and no Special Shares, Series 2 were issued to Oaktree, as Oaktree was subject to the Series B-1 Exchange Cap.
Special Voting Shares, issued and outstanding		6,089,333