Subsequent events (Preferred Share Narrative) (Details) - Subsequent Event [Member] - Oaktree Organics, L.P. and Oaktree Huntington Investment Fund II, L.P. [Member] - Series A Preferred Stock [Member] - USD ($) $ / shares in Units, $ in Millions	Oct. 25, 2025	Oct. 07, 2016
Subsequent Event [Line Items]
Subsequent Events Date		Oct. 07, 2016
Temporary Equity Shares Issued		85,000
Temporary Equity Net Proceeds On Issuance		$ 79
Temporary Equity Aggregate Amount Of Redemption Requirement		$ 85
Temporary Equity Par Or Stated Value Per Share		$ 1,000
Temporary Equity Liquidation Preference Per Share		$ 1,000
Preferred Stock Dividend Rate Percentage		8.00%
Convertible Preferred Stock Settlement Terms		At any time on or after the fifth anniversary of the Closing Date, SunOpta Foods may redeem all of the Preferred Stock for an amount, per share of Preferred Stock, equal to the value of the liquidation preference at such time. Upon certain events involving a change of control of the Company, SunOpta Foods must use reasonable efforts to provide the Holders with the option to exchange shares of the Preferred Stock for a security in the surviving or successor entity that has the same rights, preferences and privileges as the Preferred Stock as adjusted for the change of control. SunOpta Foods will also offer to redeem the Preferred Stock at an amount per share equal to the greater of (i) the liquidation preference plus an amount equal to the value of incremental dividends that would have accrued through to the fifth anniversary of the Closing Date and (ii) the amount payable per Common Share in such change of control multiplied by the Exchange Rate.
Convertible Preferred Stock Terms Of Conversion		At any time, the Holders may exchange their shares of Preferred Stock, in whole or in part, into the number of Common Shares equal to, per share of Preferred Stock, the quotient of the liquidation preference divided by $7.50 (such price, the “Exchange Price” and such quotient, the “Exchange Rate”). As at October 7, 2016, the aggregate shares of Preferred Stock outstanding were exchangeable into 11,333,333 Common Shares. The Exchange Price is subject to certain anti-dilution adjustments, including a weighted-average adjustment for issuances of Common Shares below the Exchange Price, provided that the Exchange Price may not be lower than $7.00 (subject to adjustment in certain circumstances).
Preferred Stock Redemption Price Per Share		$ 7.5
Preferred Stock Voting Rights		In connection with the Subscription Agreement, 11,333,333 Special Shares, Series 1 (the “Special Voting Shares”) of the Company were issued to the Investors, which entitle the Investors to one vote per Special Voting Share on all matters submitted to a vote of the holders of Common Shares, together as a single class, subject to certain exceptions. As of the Closing Date, the Special Voting Shares represented an 11.7% voting interest in the Company.
Preferred Stock Participation Rights		For so long as the Investors beneficially own or control at least 50% of the Preferred Stock issued on the Closing Date, including any corresponding Common Shares into which such Preferred Stock are exchanged, the Investors will be entitled to (i) participation rights with respect to future equity offerings of the Company; and (ii) governance rights, including the right to approve certain actions proposed to be taken by the Company and its subsidiaries
Minimum [Member]
Subsequent Event [Line Items]
Preferred Stock Redemption Price Per Share		$ 7
Scenario Forecast [Member] | Minimum [Member]
Subsequent Event [Line Items]
Preferred Stock Dividend Rate Percentage	12.50%