Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	Dec. 28, 2016	Dec. 30, 2015
Valuation Allowance [Line Items]
Tax credit carryforward	$ 13,541	$ 20,691
Alternative minimum tax credit carryforwards	3,534	5,344
Valuation allowance	12,567	$ 12,395
Valuation allowance, amount to be credited to paid-in capital	2,000
General Business Tax Credit Carryforward [Member]
Valuation Allowance [Line Items]
Tax credit carryforward	17,000
Tax credit carryforwards unrecognized	6,900
Alternative Minimum Tax Credit Carryforward [Member]
Valuation Allowance [Line Items]
Alternative minimum tax credit carryforwards	3,500
South Carolina NOL Carryforwards [Member]
Valuation Allowance [Line Items]
Valuation allowance	$ 9,700