Accounts payable and accrued liabilities (Details) - USD ($) $ in Thousands	Dec. 29, 2018	Dec. 30, 2017
Payables and Accruals [Abstract]
Accounts Payable, Current	$ 115,297	$ 94,992
Employee-related Liabilities, Current	8,817	15,161
Accrued Grain Liabilities Current	15,322	15,039
Loss Contingency Accrual	3,792	6,980
Interest Payable Current	5,346	5,496
Accrued Product Recall Settlement	0	2,250
Dividends Payable	1,700	1,700
Other Accrued Liabilities, Current	5,097	19,746
Accounts Payable and Accrued Liabilities, Current, Total	$ 155,371	$ 161,364