Derivative Financial Instruments (Details 2) (USD $)	3 Months Ended		6 Months Ended
	Jun. 29, 2013	Jun. 30, 2012	Jun. 29, 2013	Jun. 30, 2012
Derivative Instruments, Gain (Loss)
Reclassification of interest rate swap losses included in accumulated other comprehensive loss into earnings in the next 12 months	$ (500,000)		$ (500,000)
Cash flow hedges | Interest rate swaps
Derivative Instruments, Gain (Loss)
Gain (Loss) Recognized in OCI on Derivatives (Effective Portion) during period	1,101,000	(6,000)	1,144,000	(138,000)
Cash flow hedges | Interest rate swaps | Rent expenses
Derivative Instruments, Gain (Loss)
Loss Reclassified from Accumulated OCI into Income (Effective Portion), included in rent and interest expense during period		(447,000)		(880,000)
Cash flow hedges | Interest rate swaps | Interest expense
Derivative Instruments, Gain (Loss)
Loss Reclassified from Accumulated OCI into Income (Effective Portion), included in rent and interest expense during period	$ (141,000)		$ (322,000)