Description of Business and Significant Accounting Policies	3 Months Ended
Mar. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Significant Accounting Policies [Text Block]	1. Description of Business and Significant Accounting Policies SunOpta Inc. (the "Company" or "SunOpta") was incorporated under the laws of Canada on November 13, 1973. The Company operates businesses focused on a healthy products portfolio that promotes sustainable well-being. The Company's two reportable segments, Global Ingredients and Consumer Products, operate in the natural, organic and specialty food sectors and utilize an integrated business model to bring cost-effective and quality products to market. Basis of Presentation The interim consolidated financial statements of the Company have been prepared in accordance with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X promulgated under the Securities Exchange Act of 1934, as amended, and in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") for interim financial information. Accordingly, these condensed interim consolidated financial statements do not include all of the disclosures required by U.S. GAAP for annual financial statements. In the opinion of management, all adjustments considered necessary for fair presentation have been included and all such adjustments are of a normal, recurring nature. Operating results for the quarter ended March 30, 2019 are not necessarily indicative of the results that may be expected for the full fiscal year ending December 28, 2019 or for any other period. The interim consolidated financial statements include the accounts of the Company and its subsidiaries, and have been prepared on a basis consistent with the annual consolidated financial statements for the year ended December 29, 2018, except as described below under "Recent Accounting Pronouncements - Adoption of New Accounting Standards". For further information, refer to the consolidated financial statements, and notes thereto, included in the Company's Annual Report on Form 10-K for the fiscal year ended December 29, 2018. Fiscal Year The fiscal year of the Company consists of a 52- or 53-week period ending on the Saturday closest to December 31. Fiscal year 2019 is a 52-week period ending on December 28, 2019, with quarterly periods ending on March 30, June 29 and September 28, 2019. Fiscal year 2018 was a 52-week period ending on December 29, 2018, with quarterly periods ending on March 31, June 30 and September 29, 2018. Recent Accounting Pronouncements Adoption of New Accounting Standard In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2016-02, "Leases" ("ASC Topic 842"), which amends various aspects of legacy accounting guidance for leases, including the recognition of right-of-use assets and lease liabilities for leases classified as operating leases. The Company adopted ASC Topic 842 on a modified retrospective basis beginning the first quarter of 2019, and elected the transition option not to apply the new guidance, including disclosure requirements, in comparative reporting periods. Upon adoption, the Company also elected to apply the practical expedients available under the standard to not reassess its prior conclusions about lease identification, lease classification and initial direct costs. As a result, the adoption of ASC Topic 842 did not result in any cumulative-effect adjustment to the Company's opening accumulated deficit. The adoption of the new guidance resulted in the recognition of operating lease right-of-use assets and lease liabilities on the Company's consolidated balance sheet as at March 30, 2019, while the accounting for finance leases remained unchanged. The new guidance did not have any impact on the consolidated results of operations or cash flows of the Company for the first quarter of 2019. See note 7 for additional disclosures under ASC Topic 842. Recently Issued Accounting Standard, Not Adopted as at March 30, 2019 In June 2016, the FASB issued ASU 2016-13, "Measurement of Credit Losses on Financial Instruments", which requires measurement and recognition of expected versus incurred credit losses for most financial assets. The new guidance is effective for interim and annual periods beginning after December 15, 2019. The Company is currently assessing the impact that this standard will have on its consolidated financial statements.

Description of Business and Significant Accounting Policies

3 Months Ended

Mar. 30, 2019

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Description of Business and Significant Accounting Policies [Text Block]

1. Description of Business and Significant Accounting Policies

SunOpta Inc. (the "Company" or "SunOpta") was incorporated under the laws of Canada on November 13, 1973. The Company operates businesses focused on a healthy products portfolio that promotes sustainable well-being. The Company's two reportable segments, Global Ingredients and Consumer Products, operate in the natural, organic and specialty food sectors and utilize an integrated business model to bring cost-effective and quality products to market.

Basis of Presentation

The interim consolidated financial statements of the Company have been prepared in accordance with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X promulgated under the Securities Exchange Act of 1934, as amended, and in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") for interim financial information. Accordingly, these condensed interim consolidated financial statements do not include all of the disclosures required by U.S. GAAP for annual financial statements. In the opinion of management, all adjustments considered necessary for fair presentation have been included and all such adjustments are of a normal, recurring nature. Operating results for the quarter ended March 30, 2019 are not necessarily indicative of the results that may be expected for the full fiscal year ending December 28, 2019 or for any other period. The interim consolidated financial statements include the accounts of the Company and its subsidiaries, and have been prepared on a basis consistent with the annual consolidated financial statements for the year ended December 29, 2018, except as described below under "Recent Accounting Pronouncements - Adoption of New Accounting Standards". For further information, refer to the consolidated financial statements, and notes thereto, included in the Company's Annual Report on Form 10-K for the fiscal year ended December 29, 2018.

Fiscal Year

The fiscal year of the Company consists of a 52- or 53-week period ending on the Saturday closest to December 31. Fiscal year 2019 is a 52-week period ending on December 28, 2019, with quarterly periods ending on March 30, June 29 and September 28, 2019. Fiscal year 2018 was a 52-week period ending on December 29, 2018, with quarterly periods ending on March 31, June 30 and September 29, 2018.

Recent Accounting Pronouncements

Adoption of New Accounting Standard

In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2016-02, "Leases" ("ASC Topic 842"), which amends various aspects of legacy accounting guidance for leases, including the recognition of right-of-use assets and lease liabilities for leases classified as operating leases. The Company adopted ASC Topic 842 on a modified retrospective basis beginning the first quarter of 2019, and elected the transition option not to apply the new guidance, including disclosure requirements, in comparative reporting periods. Upon adoption, the Company also elected to apply the practical expedients available under the standard to not reassess its prior conclusions about lease identification, lease classification and initial direct costs. As a result, the adoption of ASC Topic 842 did not result in any cumulative-effect adjustment to the Company's opening accumulated deficit. The adoption of the new guidance resulted in the recognition of operating lease right-of-use assets and lease liabilities on the Company's consolidated balance sheet as at March 30, 2019, while the accounting for finance leases remained unchanged. The new guidance did not have any impact on the consolidated results of operations or cash flows of the Company for the first quarter of 2019.

See note 7 for additional disclosures under ASC Topic 842.

Recently Issued Accounting Standard, Not Adopted as at March 30, 2019

In June 2016, the FASB issued ASU 2016-13, "Measurement of Credit Losses on Financial Instruments", which requires measurement and recognition of expected versus incurred credit losses for most financial assets. The new guidance is effective for interim and annual periods beginning after December 15, 2019. The Company is currently assessing the impact that this standard will have on its consolidated financial statements.