Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2018	Jun. 28, 2017	Jun. 27, 2018	Jun. 28, 2017	Dec. 27, 2017
Property, Plant and Equipment [Abstract]
Gross value of assets under capital leases for buildings and improvements	$ 1,600		$ 1,600		$ 1,600
Accumulated depreciation of assets under capital leases	1,500		1,500		$ 1,500
Depreciation	4,300	$ 4,600	8,600	$ 8,900
Impairment of property and equipment	$ 1,708	$ 445	$ 1,708	$ 445