Revenues - Disaggregation of Revenues (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 25, 2019 USD ($)	Sep. 26, 2018 USD ($)	Sep. 25, 2019 USD ($) segment	Sep. 26, 2018 USD ($)
Revenues [Abstract]
Number of segments | segment			1
Disaggregation of Revenue [Line Items]
Total operating revenue	$ 124,258	$ 158,023	$ 427,553	$ 470,630
Franchisor Owned Outlet [Member]
Disaggregation of Revenue [Line Items]
Total operating revenue	63,582	103,609	257,574	307,543
Franchisor Owned Outlet [Member] | Sales Channel, Directly to Consumer [Member]
Disaggregation of Revenue [Line Items]
Total operating revenue	63,582	103,609	257,574	307,543
Royalties [Member] | Sales Channel, Through Intermediary [Member]
Disaggregation of Revenue [Line Items]
Total operating revenue	27,830	25,518	79,742	75,875
Advertising [Member] | Sales Channel, Through Intermediary [Member]
Disaggregation of Revenue [Line Items]
Total operating revenue	20,756	19,546	59,582	58,386
Initial and Other Fees [Member] | Sales Channel, Through Intermediary [Member]
Disaggregation of Revenue [Line Items]
Total operating revenue	1,356	1,415	4,250	4,642
Occupancy [Member] | Sales Channel, Through Intermediary [Member]
Disaggregation of Revenue [Line Items]
Total operating revenue	10,734	7,935	26,405	24,184
Franchise [Member]
Disaggregation of Revenue [Line Items]
Total operating revenue	60,676	54,414	169,979	163,087
Franchise [Member] | Sales Channel, Through Intermediary [Member]
Disaggregation of Revenue [Line Items]
Total operating revenue	$ 60,676	$ 54,414	$ 169,979	$ 163,087