Other expense, net (Narrative) (Details)	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss Contingency Settlement Agreement Terms	In connection with the exit from the flexible resealable pouch product lines and operations, the Company agreed to an upfront cash settlement of the remaining rebate obligation, resulting in a recovery of $1.0 million recognized in 2017.	In 2016, the Company recorded a charge of $9.0 million related to the settlement of a product recall dispute with a customer involving certain flexible resealable pouch products manufactured by the Company in 2013. The settlement amount included up to $4.0 million in rebates payable to the customer over a four-year period.