Business and Summary of Significant Accounting Policies (Revenue Recognition) (Details) $ in Millions	12 Months Ended
	Jan. 02, 2018 USD ($) restaurant	Jan. 03, 2017 USD ($) restaurant	Dec. 29, 2015 USD ($) restaurant
Franchisor Disclosure [Line Items]
Percent of gift cards expected to be unredeemed (percent)	6.00%
Gift card estimated redemption period	18 months
Franchise [Member]
Franchisor Disclosure [Line Items]
Number of restaurants	66	75	70
Number of restaurants opened during period	3	6	19
Gift Card Breakage
Franchisor Disclosure [Line Items]
Gift cards breakage | $	$ 0.3	$ 0.3	$ 0.3