Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	Sep. 25, 2019	Dec. 27, 2018	Dec. 26, 2018	Dec. 28, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease liabilities	$ 153,883	$ 101,300
Operating lease right-of-use assets, net	$ 143,371	94,100	$ 0
Cumulative effect adjustment		(394)		$ (15,446)
(Deficit) [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment		(400)
Deferred Tax Asset [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment		$ 100