Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 27, 2016	Dec. 29, 2015
Assets:
General business credit carryforwards	$ 21,271	$ 18,915
Insurance reserves	10,903	11,843
Profit sharing and vacation	9,916	8,906
Unfavorable leasehold interests	2,145	2,815
Deferred rent	4,247	3,671
Other	2,112	2,193
Total deferred tax assets	50,594	48,343
Liabilities:
Depreciation and amortization	(226,672)	(231,500)
Debt refinancing	(756)	(1,136)
Favorable leasehold interests	(2,483)	(2,915)
Other	(3,140)	(2,555)
Total deferred tax liabilities	(233,051)	(238,106)
Net deferred tax liability	$ (182,457)	$ (189,763)