Unaudited Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jul. 03, 2018	Jul. 04, 2017	Jul. 03, 2018	Jul. 04, 2017
Income Statement [Abstract]
Revenues		$ 287,634	$ 265,817	$ 566,157	$ 523,633
Restaurant operating costs (excluding depreciation and amortization):
Cost of sales	[1]	72,026	69,517	141,997	134,912
Labor and benefits		101,986	94,113	202,419	186,496
Occupancy and operating	[1]	59,073	54,872	116,576	108,816
General and administrative		15,851	14,205	30,982	28,501
Depreciation and amortization		17,620	17,052	35,074	33,801
Restaurant opening		835	1,258	1,432	2,671
Loss on disposal and impairment of assets		1,123	2,411	2,184	3,098
Total costs and expenses		268,514	253,428	530,664	498,295
Income from operations		19,120	12,389	35,493	25,338
Other (expense) income:
Interest expense, net		(1,381)	(1,113)	(2,768)	(2,001)
Other income (expense), net		81	266	(19)	1,051
Total other expense		(1,300)	(847)	(2,787)	(950)
Income before income taxes		17,820	11,542	32,706	24,388
Income tax expense		875	1,903	1,097	5,483
Net income		$ 16,945	$ 9,639	$ 31,609	$ 18,905
Net income per share:
Basic		$ 0.81	$ 0.45	$ 1.52	$ 0.87
Diluted		$ 0.79	$ 0.44	$ 1.49	$ 0.85
Weighted average number of shares outstanding:
Basic		20,880	21,573	20,733	21,752
Diluted		21,477	22,074	21,282	22,202
Cash dividends declared per common share		$ 0.11		$ 0.22

[1] Related party costs included in cost of sales are $22,279 and $21,812 for the thirteen weeks ended July 3, 2018 and July 4, 2017, respectively, and $43,581 and $41,889 for the twenty-six weeks ended July 3, 2018 and July 4, 2017, respectively. Related party costs included in occupancy and operating are $2,472 and $2,310 for the thirteen weeks ended July 3, 2018 and July 4, 2017, respectively, and $4,934 and $4,543 for the twenty-six weeks ended July 3, 2018 and July 4, 2017, respectively. See Note 5 for further information.