Intangible assets (Tables)

12 Months Ended

Dec. 29, 2018

Goodwill And Intangible Assets Disclosure [Abstract]

Schedule Of Acquired Finite Lived Intangible Assets By Major Class [Text Block]

	December 29, 2018
	Cost	Accumulated amortization	Net book value
	$	$	$
Customer relationships	210,845	49,937	160,908
Patents, trademarks and other	1,919	1,852	67
	212,764	51,789	160,975
	December 30, 2017
	Cost	Accumulated amortization	Net book value
	$	$	$
Customer relationships	211,176	39,274	171,902
Patents, trademarks and other	1,919	1,762	157
	213,095	41,036	172,059

Schedule of Finite-Lived Intangible Assets [Table Text Block]

The following is a summary of changes in intangible assets:

		Customer	Patents, trademarks
		relationships	and other	Total
		$	$	$
Balance at December 31, 2016		183,258	266	183,524
	Amortization	(11,086)	(109)	(11,195)
	Impairment	(456)	-	(456)
	Foreign exchange	186	-	186
Balance at December 30, 2017		171,902	157	172,059
	Amortization	(10,948)	(90)	(11,038)
	Foreign exchange	(46)	-	(46)
Balance at December 29, 2018		160,908	67	160,975

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

The Company estimates that the aggregate future amortization expense associated with finite-life intangible assets in each of the next five fiscal years and thereafter will be as follows:

	2019	2020	2021	2022	2023	Thereafter	Total
	$	$	$	$	$	$	$
Amortization expense	11,013	10,382	10,112	10,112	10,112	109,244	160,975