Revenues Disaggregation of Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2019	Jun. 27, 2018	Jun. 26, 2019	Jun. 27, 2018
Disaggregation of Revenue [Line Items]
Total operating revenue	$ 151,884	$ 157,334	$ 303,295	$ 312,607
Franchisor Owned Outlet [Member]
Disaggregation of Revenue [Line Items]
Total operating revenue	95,447	102,741	193,992	203,934
Franchisor Owned Outlet [Member] | Sales Channel, Directly to Consumer [Member]
Disaggregation of Revenue [Line Items]
Total operating revenue	95,447	102,741	193,992	203,934
Royalties [Member] | Sales Channel, Through Intermediary [Member]
Disaggregation of Revenue [Line Items]
Total operating revenue	26,672	25,192	51,912	50,357
Advertising [Member] | Sales Channel, Through Intermediary [Member]
Disaggregation of Revenue [Line Items]
Total operating revenue	19,884	19,530	38,826	38,840
Initial and other fees [Member] | Sales Channel, Through Intermediary [Member]
Disaggregation of Revenue [Line Items]
Total operating revenue	1,755	1,810	2,894	3,227
Occupancy [Member] | Sales Channel, Through Intermediary [Member]
Disaggregation of Revenue [Line Items]
Total operating revenue	8,126	8,061	15,671	16,249
Franchise [Member]
Disaggregation of Revenue [Line Items]
Total operating revenue	56,437	54,593	109,303	108,673
Franchise [Member] | Sales Channel, Through Intermediary [Member]
Disaggregation of Revenue [Line Items]
Total operating revenue	$ 56,437	$ 54,593	$ 109,303	$ 108,673