Document and Entity Information - shares	9 Months Ended
	Oct. 03, 2015	Nov. 06, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Document Period End Date	Oct. 03, 2015
Amendment Flag	false
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q3
Entity Registrant Name	SunOpta Inc.
Entity Central Index Key	0000351834
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	--01-02
Entity Filer Category	Large Accelerated Filer
Entity Well Known Seasoned Issuer	Yes
Trading Symbol	STKL
Entity Common Stock Shares Outstanding		85,339,007