Earnings per share (Table) (Details) (USD $)	12 Months Ended
	Jan. 03, 2015	Dec. 28, 2013	Dec. 29, 2012
Earnings Per Share Abstract
Income (Loss) from Continuing Operations Attributable to Parent	$ 11,347,000	$ (8,696,000)	$ 20,722,000
Earnings (loss) from discontinued operations, net of income taxes	1,754,000	172,000	3,502,000
Earnings (loss) attributable to SunOpta Inc.	$ 13,101,000	$ (8,524,000)	$ 24,224,000
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Weighted Average Number of Shares Outstanding, Basic	66,835,201	66,288,147	65,897,969
Weighted Average Number of Shares Outstanding, Diluted	68,370,647	67,832,125	66,611,397
Earnings (loss) per share - basic
from continuing operations basic	$ 0.17	$ (0.13)	$ 0.31
from discontinued operations basic	$ 0.03	$ 0	$ 0.05
Earnings Per Share Total	$ 0.2	$ (0.13)	$ 0.37
Earnings (loss) per share - diluted
from continuing operations diluted	$ 0.17	$ (0.13)	$ 0.31
from discontinued operations diluted	$ 0.03	$ 0	$ 0.05
Earnings Per Share Diluted Total	$ 0.19	$ (0.13)	$ 0.36
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	63,000	0	2,045,200
Options Held [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Dilutive Securities, Effect on Basic Earnings Per Share, Including Options and Restrictive Stock Units	1,007,596	1,165,133	551,723
Warrant [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Dilutive Securities, Effect on Basic Earnings Per Share, Including Options and Restrictive Stock Units	527,850	378,845	161,705