Annual report pursuant to Section 13 and 15(d)

Employee Stock Purchase Plan (Details)

v3.22.0.1
Employee Stock Purchase Plan (Details)
$ / shares in Units, $ in Millions
1 Months Ended 12 Months Ended
Jul. 31, 2017
restaurant
shares
Dec. 26, 2021
USD ($)
$ / shares
shares
Dec. 27, 2020
USD ($)
$ / shares
shares
Dec. 29, 2019
USD ($)
$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total stock-based compensation cost | $   $ 6.6 $ 4.3 $ 3.3
Employee Stock Purchase Plan        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Maximum number of shares of the company's common stock that may be issued or transferred (in shares) 100,000      
Maximum percentage of base compensation that can be contributed by the eligible team members 15.00%      
Estimated subscription date fair value (as a percent) 85.00%      
Requisite employment period to be eligible to participate in the plan 1 year      
Requisite working hours per week to be eligible to participate in the plan | restaurant 20      
Operational period of the plan 6 months      
Stock Issued During Period, Shares, Employee Stock Purchase Plans   42,563 40,462  
Number of shares available for future issuance under the plan (in shares)   119,426    
Risk-free interest rate (as a percent)   0.30% 0.10% 1.50%
Expected years until exercise   6 months 6 months 6 months
Expected stock volatility (as a percent)   53.94% 50.40% 41.82%
Dividend yield (as a percent)   0.00% 0.00% 0.00%
Awarded (in dollars per share) | $ / shares   $ 4.36 $ 2.16 $ 75.60
Total stock-based compensation cost | $   $ 0.2 $ 0.1 $ 0.2