Acquisition (Details) $ / shares in Units, $ in Thousands								3 Months Ended		9 Months Ended		12 Months Ended		21 Months Ended
	Aug. 20, 2019 USD ($)	Jun. 11, 2019 USD ($)	Apr. 30, 2019 USD ($) restaurant director $ / shares shares	Oct. 02, 2018 USD ($)	Sep. 05, 2018 USD ($)	Aug. 21, 2018 USD ($)	Feb. 13, 2018 USD ($)	Sep. 29, 2019 USD ($) restaurant shares	Sep. 30, 2018 USD ($)	Sep. 29, 2019 USD ($) shares	Sep. 30, 2018 USD ($)	Dec. 29, 2019 USD ($)	Dec. 30, 2018 USD ($)	Sep. 29, 2019 USD ($) restaurant	Jul. 01, 2018 USD ($)
Business Acquisition [Line Items]
Right of First Refusal, Number of States								20		20				20
Business acquisitions, purchase price										$ 131,545	$ 27,595
Proceeds from sale-leaseback transactions										7,018	4,504
Restaurant sales								$ 402,345	$ 296,917	1,061,693	871,553
Goodwill								143,568		143,568			$ 38,469	$ 143,568
April 30, 2019 Acquisition 2 [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired			220
Business Combination, Consideration Transferred			$ 259,801
June 11, 2019 Acquisition [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired		13
Business acquisitions, purchase price		$ 15,788
August 20, 2019 Acquisition [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired	1
Business acquisitions, purchase price	$ 1,108
2018 Acquisitions [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired													44
Business acquisitions, purchase price													$ 38,102
Goodwill													$ 1,677
February 13, 2018 Acquisition 2 [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired							1
Business acquisitions, purchase price							$ 0
Franchise rights															$ 300
Liabilities assumed in excess of consideration															$ 200
August 21, 2018 Acquisition 2 [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired						2
Business acquisitions, purchase price						$ 1,666
September 5, 2018 Acquisition 2 [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired					31
Business acquisitions, purchase price					$ 25,930
October 2, 2018 Acquisition [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired				10
Business acquisitions, purchase price				$ 10,506
Agreement And Plan Of Merger - Cambridge Holdings, LLC [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired | restaurant			132
Franchise rights								144,499		144,499				144,499
Goodwill								104,996		104,996				104,996
Business Combination, Consideration Transferred			$ 259,800
Business acquisition, equity interest issued or issuable, number of shares | shares			7,400,000
Business Combination, Restrictions On Stock, Term Of Restrictions On Sale Or Transfer			2 years
Business Combination, Number Of Director Nominees That May Be Designated By Counterparty | director			2
Number of Restaurants Constructed | restaurant			33
Deferred taxes								(35,264)		(35,264)				$ (35,264)
Acquired Restaurants [Member]
Business Acquisition [Line Items]
Restaurant sales								$ 89,600	$ 3,100	$ 164,900	$ 3,500
Cambridge Holdings, LLC [Member] | Agreement And Plan Of Merger - Cambridge Holdings, LLC [Member]
Business Acquisition [Line Items]
Retirement of Outstanding Indebtedness			$ 114,500
Common Stock [Member]
Business Acquisition [Line Items]
Business Acquisition, Purchase Price, Conversion, Closing Price | $ / shares			$ 9.81
Common Stock [Member] | Agreement And Plan Of Merger - Cambridge Holdings, LLC [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred			$ 145,300
Burger King Corporate [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired | restaurant								165						223
Popeyes [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired | restaurant														55
Cambridge Holdings, LLC [Member] | Series C Preferred Stock [Member]
Business Acquisition [Line Items]
Issuance (in shares) | shares										10,000
Conversion of Stock, Shares Converted | shares								7,500,000
Scenario, Forecast [Member]
Business Acquisition [Line Items]
Number of Restaurants Acquired												278
Business acquisitions, purchase price												$ 314,799