Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 27, 2016	Dec. 29, 2015
Components of accrued liabilities
Payroll and vacation	$ 22,316	$ 19,279
Accrued real estate and property taxes	5,879	5,243
Accrued capital expenditures	5,525	3,350
Sales tax payable	5,271	5,648
Other	17,746	11,327
Total accrued liabilities	$ 56,737	$ 44,847