Leases - Maturities of Lease Labilities Per Topic 842 (Details) - USD ($) $ in Thousands	Sep. 25, 2019	Dec. 27, 2018	Dec. 26, 2018
Lease Liabilities, Finance
Remainder of 2019	$ 1,256
2020	4,839
2021	4,571
2022	4,287
2023	3,769
Thereafter	25,672
Total undiscounted cash flows	44,394
Less: interest	27,175
Present value of lease liabilities	17,219
Less: current lease liabilities	1,812		$ 3,410
Long-term lease liabilities	15,407		27,181
Lease Liabilities, Operating
Remainder of 2019	6,543
2020	24,749
2021	22,629
2022	20,469
2023	17,875
Thereafter	120,696
Total undiscounted cash flows	212,961
Less: interest	59,078
Present value of lease liabilities	153,883	$ 101,300
Less: current lease liabilities	16,718		0
Long-term lease liabilities	137,165		$ 0
Lease Receipts, Operating
Remainder of 2019	8,225
2020	31,029
2021	28,145
2022	25,756
2023	22,682
Thereafter	155,741
Total undiscounted cash flows	$ 271,578