Intangible assets (Future Amortization) (Details) $ in Thousands	Dec. 29, 2018 USD ($)
Finite Lived Intangible Assets Net [Abstract]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	$ 11,013
Finite-Lived Intangible Assets, Amortization Expense, Year Two	10,382
Finite-Lived Intangible Assets, Amortization Expense, Year Three	10,112
Finite-Lived Intangible Assets, Amortization Expense, Year Four	10,112
Finite-Lived Intangible Assets, Amortization Expense, Year Five	10,112
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	109,244
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year	$ 160,975