Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 27, 2018	Jun. 28, 2017		Jun. 27, 2018	Jun. 28, 2017
Revenue:
Company restaurant sales	$ 102,741	$ 98,355		$ 203,934	$ 192,134
Franchise and license revenue	54,593	35,021		108,673	69,152
Total operating revenue	157,334	133,376	[1]	312,607	261,286	[1]
Costs of company restaurant sales:
Product costs	25,054	24,769		49,989	47,902
Payroll and benefits	41,065	38,492		82,291	75,889
Occupancy	5,435	5,503		11,082	10,237
Other operating expenses	15,021	12,933		30,071	25,504
Total costs of company restaurant sales	86,575	81,697		173,433	159,532
Costs of franchise and license revenue	29,049	10,244		57,605	19,990
General and administrative expenses	15,597	16,581		32,157	34,090
Depreciation and amortization	6,691	5,799		13,205	11,535
Operating (gains), losses and other charges, net	462	2,046		822	2,829
Total operating costs and expenses, net	138,374	116,367		277,222	227,976
Operating income	18,960	17,009		35,385	33,310
Interest expense, net	5,385	3,740		10,010	7,281
Other nonoperating income, net	(629)	(410)		(417)	(767)
Net income before income taxes	14,204	13,679		25,792	26,796
Provision for income taxes	2,578	4,930		4,407	9,674
Net income	$ 11,626	$ 8,749		$ 21,385	$ 17,122
Basic net income per share	$ 0.18	$ 0.13		$ 0.33	$ 0.24
Diluted net income per share	$ 0.18	$ 0.12		$ 0.32	$ 0.24
Basic weighted average shares outstanding	63,644	69,407		64,038	70,205
Diluted weighted average shares outstanding	66,128	71,661		66,552	72,459

[1] As disclosed in Note 2, prior period amounts have not been adjusted under the modified retrospective method of adoption of Topic 606.