Business and Summary of Significant Accounting Policies (Revenue Recognition) (Details) $ in Millions	12 Months Ended
	Jan. 01, 2019 USD ($) restaurant	Jan. 02, 2018 USD ($) restaurant	Jan. 03, 2017 USD ($) restaurant
Franchisor Disclosure [Line Items]
Gift card breakage | $	$ 1.0	$ 0.3	$ 0.3
Percent of gift cards expected to be unredeemed (percent)	8.00%
Gift card estimated redemption period	18 months
Franchise [Member]
Franchisor Disclosure [Line Items]
Number of restaurants | restaurant	65	66	75
Number of restaurants opened during period | restaurant	0	3	6
Gift Card Breakage
Franchisor Disclosure [Line Items]
Gift cards breakage | $			$ 0.3