Property and Equipment - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2018	Sep. 27, 2017	Sep. 26, 2018	Sep. 27, 2017	Dec. 27, 2017
Property, Plant and Equipment [Abstract]
Gross value of assets under capital leases for buildings and improvements	$ 1,500		$ 1,500		$ 1,600
Accumulated depreciation of assets under capital leases	1,500		1,500		$ 1,500
Depreciation	4,500	$ 4,700	13,100	$ 13,600
Impairment of property and equipment	$ 100	$ 15,000	$ 1,791	$ 15,480