Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2017	Jun. 29, 2016	Jun. 28, 2017	Jun. 29, 2016	Dec. 28, 2016
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 4,600	$ 4,000
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
Capital expenditures	7,400	8,400	19,000	$ 14,300
Capital expenditures for restaurant remodeling	1,400	100	2,800	1,600
Capital expenditures for new restaurants	4,400	$ 6,300	13,900	9,200
Impairment of property and equipment	$ 386		$ 445	$ 56