Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 27, 2017	Dec. 28, 2016
Deferred tax assets:
Self-insurance accruals	$ 4,364	$ 7,791
Capitalized leases	1,718	2,298
Accrued exit cost	487	1,074
Interest rate swaps	566	294
Pension, other retirement and compensation plans	10,328	12,378
Other accruals	443	386
Alternative minimum tax credit carryforwards	3,534	3,534
General business credit carryforwards - state and federal	13,355	13,541
Net operating loss carryforwards - state	14,096	11,753
Total deferred tax assets before valuation allowance	48,891	53,049
Less: valuation allowance	(13,078)	(12,567)
Total deferred tax assets	35,813	40,482
Deferred tax liabilities:
Intangible assets	(14,578)	(22,073)
Deferred finance costs	(111)	(125)
Fixed assets	(4,179)	(601)
Total deferred tax liabilities	(18,868)	(22,799)
Net deferred tax asset	$ 16,945	$ 17,683