Impairment Of Long-Lived Assets And Other Lease Charges (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017 USD ($)	Oct. 01, 2017 USD ($)	Jul. 02, 2017 USD ($)	Apr. 02, 2017 USD ($)	Oct. 02, 2016 USD ($)	Jul. 03, 2016 USD ($)	Apr. 03, 2016 USD ($)	Jan. 03, 2016 USD ($)	Dec. 31, 2017 USD ($)	Jan. 01, 2017 USD ($)	Jan. 03, 2016 USD ($)
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment and other lease charges	$ 800	$ 1,000	$ 400	$ 500	$ 700	$ 300	$ 200	$ 1,200	$ 2,827	$ 2,355	$ 3,078
Impairment charges									1,700	1,000	1,500
Sale Leaseback Transaction, Current Period Loss Recognized									$ 100
Sale Leaseback Losses, number of restaurants									1
Other lease charges									$ 900	$ 1,200	$ 1,600
Asset impairment charges, number of restaurants									5	4	2
Other lease charges, number of restaurants											10
Previously Impaired [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment charges									$ 700	$ 900	$ 1,300
Initial Impairments [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment charges									$ 1,100	$ 200	$ 200