Revenue from Contracts with Customers - Additional Information (Details)	12 Months Ended
	Dec. 26, 2018 USD ($) revenue_stream	Dec. 28, 2017 USD ($)	Dec. 27, 2017 USD ($)
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Number of revenue streams | revenue_stream	2
Revenue allocated to loyalty points not redeemed	$ 1,000,000		$ 400,000
Loyalty rewards program, expected loyalty points redemption period	1 year
Franchise license
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Franchise agreement term	20 years
Franchise agreement renewal term	20 years
Hardware Services
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Unsatisfied performance obligations	$ 0
Minimum
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Performance obligations expected to be satisfied, renewal term	10 years
Maximum
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Performance obligations expected to be satisfied, renewal term	20 years
Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cumulative effect of adjustment resulted in an increase in accumulated deficit		$ 3,467,000
Accounting Standards Update 2014-09 | Accumulated Deficit
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cumulative effect of adjustment resulted in an increase in accumulated deficit		$ 3,467,000