Adoption of ASU 2014-09, "Revenue from Contracts with Customers" – Transaction Price Allocated to Remaining Performance Obligations (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jan. 01, 2018
Performance Obligations by Period
Total deferred revenue	$ 34,320	$ 30,574
Franchise royalties and fees
Performance Obligations by Period
Less than 1 Year	2,389
1-2 Years	2,181
2-3 Years	1,952
3-4 Years	1,748
4-5 Years	1,465
Thereafter	3,813
Total deferred revenue	13,548
Area development fees
Performance Obligations by Period
Total deferred revenue	3,800
Customer loyalty program
Performance Obligations by Period
Total deferred revenue	$ 16,985	$ 14,724