Impairment Of Long-Lived Assets And Other Lease Charges (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 01, 2017 USD ($)	Oct. 02, 2016 USD ($)	Oct. 01, 2017 USD ($)	Oct. 02, 2016 USD ($)	Jan. 01, 2017 USD ($)
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment and other lease charges	$ 1,039	$ 685	$ 2,002	$ 1,193
Asset Impairment Charges	500	$ 300	$ 1,000	$ 900
Asset Impairment Charges, Number of Restaurants			4
Other lease charges			$ 91		$ (89)
Other Lease Charges, Number of Restaurants		3	4
Provisions for restaurant closures			$ 766		$ 59
Previously Impaired [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Asset Impairment Charges			500
Underperforming Restaurants [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Asset Impairment Charges			500
Closed Restaurants [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Other lease charges	$ 600	$ 200
Provisions for restaurant closures			$ 900