Fair Value Measurements (Fair Value Measurements - Carrying Amount and Fair Value) (Details) - USD ($) $ in Thousands		Sep. 26, 2020	Dec. 28, 2019
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Finance lease obligations	[1]	$ 18,926	$ 19,483
Operating Lease, Liability		23,478	25,295
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and cash equivalents		19	769
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt and finance leases, including current portion		55,061	68,868
Finance lease obligations		18,926	19,483
Operating Lease, Liability		23,478	25,295
Interest rate swaps		2,020	1,653
Estimate of Fair Value, Fair Value Disclosure [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and cash equivalents		19	769
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt and finance leases, including current portion		56,685	72,115
Finance lease obligations		20,054	20,361
Operating Lease, Liability		23,478	25,295
Interest rate swaps		$ 2,020	$ 1,653

[1] Includes leases classified as failed sale-leaseback transactions.