Commitments and contingencies (Tables)

12 Months Ended

Dec. 30, 2017

Commitments And Contingencies Disclosure [Abstract]

Contractual Obligation, Fiscal Year Maturity Schedule [Table Text Block]

Minimum commitments under operating leases, principally for processing facilities, warehouse and distribution facilities, and equipment for the next five fiscal years and thereafter are as follows:

	$
2018	19,048
2019	15,820
2020	13,250
2021	8,902
2022	7,011
Thereafter	7,868
	71,899