Acquisition (Details)	3 Months Ended			12 Months Ended	15 Months Ended
	Apr. 01, 2018 USD ($)	Jul. 02, 2017	Apr. 02, 2017 USD ($)	Dec. 31, 2017 USD ($)	Apr. 01, 2018 USD ($)
Business Acquisition [Line Items]
Right of First Refusal, Number of States	20				20
Number of Restaurants Acquired					65
Business acquisitions, purchase price	$ 0		$ 20,373,000		$ 37,923,000
Proceeds from sale-leaseback transactions	1,292,000		0
Restaurant sales	$ 271,586,000		$ 239,852,000
November 17, 2015 Acquisition 2 [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired	1
Business acquisitions, purchase price	$ 0
February 28, 2017 Acquisition [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired			43
Business acquisitions, purchase price	20,366,000
June 6, 2017 Acquisition [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired		17
Business acquisitions, purchase price			$ 16,355,000
Acquired Restaurants [Member]
Business Acquisition [Line Items]
Restaurant sales	$ 21,400,000		$ 4,700,000
October 1, 2015 Acquisition [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired				4
Business acquisitions, purchase price				$ 1,202,000
October 20, 2015 Acquisition [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired				64
Business acquisitions, purchase price				$ 37,923,000