Leases (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2021 USD ($) lease restaurant	Sep. 23, 2020 USD ($) restaurant	Sep. 29, 2021 USD ($) lease restaurant	Sep. 23, 2020 USD ($) restaurant	Dec. 30, 2020 USD ($)
Lessee, Lease, Description [Line Items]
Property and equipment held under operating leases, net ("ROU asset")	$ 172,823		$ 172,823		$ 177,129
Operating Lease, Liability	$ 192,515		$ 192,515
Initial lease term	20 years		20 years
Renewal term	5 years		5 years
Number of Restaurants with lease modification | restaurant	4	2	16	9
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability			$ 13,848	$ 3,221
Number of restaurants primarily responsible for impairment | restaurant			2
Operating Lease, Impairment Loss				500
Impairment of Right-of-Use Assets			$ 407	$ 543
Maximum
Lessee, Lease, Description [Line Items]
Operating Lease, Impairment Loss			$ 400
Texas
Lessee, Lease, Description [Line Items]
Number of restaurants primarily responsible for impairment | restaurant				1
Number Of Restaurants Closed | restaurant	1		1
California
Lessee, Lease, Description [Line Items]
Number of restaurants primarily responsible for impairment | restaurant	3	4	3
Number Of Restaurants Closed | restaurant	1		1
Lease Not Yet Commenced [Member]
Lessee, Lease, Description [Line Items]
Number Of Leases | lease			1
Property Lease [Member]
Lessee, Lease, Description [Line Items]
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability			$ 13,848	$ 3,180
Equipment Lease [Member]
Lessee, Lease, Description [Line Items]
Number Of Finance Leases | lease	9		9
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability			$ 0	41
Property lease modification [Member]
Lessee, Lease, Description [Line Items]
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 2,600	$ 300	$ 13,800	$ 2,000
Facility Leases [Member]
Lessee, Lease, Description [Line Items]
Number Of Finance Leases | lease	2		2