Derivative and Hedging Activities (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 24, 2013	Sep. 25, 2012	Sep. 24, 2013	Sep. 25, 2012	Dec. 25, 2012
Fair value of derivative instruments
Fair value of Derivative Liabilities, Interest rate swaps	$ 2,980,000		$ 2,980,000		$ 4,016,000
Fair value of Derivative Liabilities	2,980,000		2,980,000		4,016,000
Interest rate cash flow hedges
Gain (loss) recognized in AOCI, net of tax (effective portion)	97,000	28,000	634,000	(78,000)
Loss reclassified from AOCI to income (effective portion)	378,000	363,000	1,106,000	1,082,000
Interest rate swap, entered October 22, 2008
Interest Rate Swaps
Fixed interest rate of derivative (as a percent)	3.83%		3.83%
Notional amount of hedge obligation	25,000,000		25,000,000
Reference rate for interest receivable			1-month LIBOR
Interest rate swap, entered January 7, 2009
Interest Rate Swaps
Fixed interest rate of derivative (as a percent)	2.34%		2.34%
Notional amount of hedge obligation	$ 25,000,000		$ 25,000,000
Reference rate for interest receivable			1-month LIBOR