System Optimization Losses (Gains), Net Summary of DavCo and NPC Transactions (Details) $ in Thousands		3 Months Ended				12 Months Ended
	May 31, 2017 Restaurant	Jul. 02, 2017 USD ($)	Jan. 01, 2017 USD ($)	Oct. 02, 2016 USD ($)	Apr. 03, 2016 USD ($)	Dec. 31, 2017 USD ($)	Jan. 01, 2017 USD ($)	Jan. 03, 2016 USD ($)
Property, Plant and Equipment
Goodwill			$ 741,410			$ 743,334	$ 741,410	$ 770,781
Proceeds from sales						81,516	262,173	204,388
System optimization (losses) gains, net		$ (41,050)	$ 23,825	$ 37,756	$ 8,426	(39,076)	71,931	74,009
DavCo Acquisition
Property, Plant and Equipment
Restaurants acquired from franchisees | Restaurant	140
Restaurants closed before acquisition | Restaurant	7
Total consideration paid						86,788
Net assets held for sale						70,688
Capital lease assets						49,360
Deferred taxes						27,830
Capital lease obligations						(97,797)
Net unfavorable leases						(22,330)
Other liabilities						(6,924)
Total identifiable net assets						20,827
Goodwill						65,961
Favorable Lease Assets						1,229
Unfavorable Lease Liabilities						23,559
Supplemental deferred purchase price						6,269
Tax deductible goodwill						21,795
NPC Disposition
Property, Plant and Equipment
Significant Changes, Franchises Sold | Restaurant	140
Number of sold restaurants to be reimaged | Restaurant	90
Number of restaurants to be built by the end of 2022 | Restaurant	15
Proceeds from sales						70,688
Net Assets Sold						(70,688)
Goodwill						(65,961)
Net favorable leases						24,034
Other						(1,708)
System optimization (losses) gains, net						(43,635)	$ 0	$ 0
Favorable Lease Assets						30,068
Unfavorable Lease Liabilities						$ 6,034