System Optimization (Gains) Losses, Net Summary of Disposition Activity (Details) $ in Thousands		3 Months Ended		6 Months Ended		12 Months Ended
	May 31, 2017 USD ($) Restaurant	Jul. 01, 2018 USD ($) Restaurant	Jul. 02, 2017 USD ($)	Jul. 01, 2018 USD ($) Restaurant	Jul. 02, 2017 USD ($) Restaurant	Dec. 31, 2017 USD ($)
System optimization gains (losses), net
Company-operated restaurant ownership percentage		5.00%		5.00%
System optimization gains (losses), net		$ 92	$ (41,050)	$ (478)	$ (39,643)
Proceeds from sales				1,814	77,980
Payment for supplemental purchase price				$ 6,100	0
Sale of Company-operated restaurants to franchisees
System optimization gains (losses), net
Number of restaurants sold to franchisees | Restaurant		3		3
System optimization gains (losses), net		$ 89	0	$ 89	0
Post closing adjustments on sales of restaurants		(13)	27	(225)	927
Proceeds from sales		1,436		1,436
Net Assets Sold		(1,139)		(1,139)
Goodwill		(208)		(208)
Cash proceeds from post closing adjustments, net of payments			300	$ 6	300
Recognition of deferred gain on sale of property					$ 312
Sale of franchise-operated restaurant to franchisee
System optimization gains (losses), net
Number of restaurants sold to franchisees | Restaurant				64	270
Sale of Other Assets
System optimization gains (losses), net
System optimization gains (losses), net		16	2,072	$ (342)	$ 2,579
Proceeds from sales		27	5,342	372	6,992
Recognition of deferred gain on sale of property					375
NPC Disposition
System optimization gains (losses), net
Number of restaurants sold to franchisees | Restaurant	140
System optimization gains (losses), net		$ 0	$ (43,149)	0	(43,149)
Proceeds from sales	$ 70,688
Goodwill					(65,503)
Selling and other costs					(1,680)
Net favorable leases					$ 24,034
DavCo Acquisition
System optimization gains (losses), net
Restaurants acquired from franchisees | Restaurant	140
Total consideration paid	$ 86,788
Supplemental purchase price						$ 6,269
Payment for supplemental purchase price				$ 6,100