Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 25, 2013	Dec. 26, 2012
Valuation Allowance [Line Items]
Tax benefit recognized	$ (270,000)	$ (420,000)	$ (661,000)
Out-of-period discrete tax adjustment	(500,000)		1,700,000
Deferred tax benefit	13,215,000	9,100,000	11,423,000
Tax credit carryforward	22,089,000	29,490,000
Alternative minimum tax credit carryforwards	7,811,000	10,344,000
Valuation allowance, amount to be credited to paid-in capital	2,000,000
South Carolina net operating loss carryforwards	78.00%
Unrecognized tax benefits	0	0
General Business Tax Credit Carryforward [Member]
Valuation Allowance [Line Items]
Deferred tax benefit		300,000
Tax credit carryforward	24,700,000
Tax credit carryforwards unrecognized	5,300,000
Alternative Minimum Tax Credit Carryforward [Member]
Valuation Allowance [Line Items]
Alternative minimum tax credit carryforwards	7,800,000
AMT NOL Carryforwards [Member]
Valuation Allowance [Line Items]
NOL carryforwards	28,000,000
State and Local Jurisdiction [Member]
Valuation Allowance [Line Items]
Tax benefit recognized		(200,000)
State job tax credits	700,000	800,000
Additional state job tax credits	500,000
Out-of-period discrete tax adjustment			$ 1,600,000