Leases - Real estate leases other information (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 24, 2019 USD ($)	Sep. 24, 2019 USD ($) lease
Leases
Cash paid for amounts included in measurement of operating lease liabilities	$ 12,268	$ 36,384
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 14,229	$ 41,102
Weighted-average remaining lease term	17 years 10 months 17 days	17 years 10 months 17 days
Weighted-average discount rate	6.78%	6.78%
Operating lease not yet taken possession	$ 11,200	$ 11,200
Number of finance leases | lease		1
Right-of-use asset	1,800	$ 1,800
Lease liability	$ 2,100	$ 2,100