Leases Schedule of Accounting Pronouncements (Details) - USD ($) $ in Thousands	Sep. 25, 2019	Dec. 27, 2018	Dec. 26, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Prepaid Expense and Other Assets, Current	$ 1,723		$ 1,984
Property and equipment, net	(304,350)		(261,854)
Operating lease assets	279,975		0
Deferred income taxes, net	(268,855)		(242,533)
Deemed landlord financing	0		(20,846)
Deferred rent	0		47,864
Long-term operating lease liabilities	316,161		0
Other long-term liabilities	14,910		10,498
Retained earnings	56,460		30,404
Non-controlling interests	$ 27,679		$ 47,380
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Prepaid Expense and Other Assets, Current		$ (6)
Property and equipment, net		(11,448)
Operating lease assets		229,885
Deferred income taxes, net		(121)
Deemed landlord financing		(20,846)
Deferred rent		(47,862)
Long-term operating lease liabilities		277,224
Other long-term liabilities		4,611
Retained earnings		4,136
Non-controlling interests		$ 1,059