Impact on Earnings from Interest Rate Swaps (Details) - Interest Rate Swap [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 04, 2015	Jun. 28, 2014	Jul. 04, 2015	Jun. 28, 2014
Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(loss) recognized in accumulated other comprehensive income	$ (4)	$ (1,008)	$ (1,301)	$ (1,111)
Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(loss) reclassified from accumulated other comprehensive income (effective portion)	(489)	(572)	(974)	(1,115)
Other Expense
Derivative Instruments, Gain (Loss) [Line Items]
Gain/(loss) recognized in income (ineffective portion)	$ 2	$ (48)	$ 15	$ (17)