Other Comprehensive Income (Loss) (Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated other comprehensive loss - interest rate swaps			$ (144)
Accumulated other comprehensive - postretirement liabilities			360
Accumulated other comprehensive loss - total			216
Unrealized gain (loss) on interest rate swaps	(645)	235	(1,227)	247
Reclassification of loss into earnings from interest rate swaps	54	50	107	71
Amortization of unrealized loss on dedesignated interest rate swaps	0	30	0	98
Reclassification of net actuarial gain into earnings from postretirement benefit plans	(6)	(6)	(13)	(11)
Reclassification of prior service credits into earnings from postretirement benefit plans	(14)	(14)	(27)	(27)
Accumulated other comprehensive loss - interest rate swaps	(1,264)		(1,264)
Accumulated other comprehensive - postretirement liabilities	320		320
Accumulated other comprehensive loss - total	(944)		(944)
Unrealized gain (loss) on interest rate swaps - income taxes	(395)	144	(753)	152
Reclassification of loss into earnings from interest rate swaps - income taxes	32	30	65	44
Amortization of unrealized loss on dedesignated interest rate swap - income taxes	0	18	0	60
Reclassification of net actuarial gain into earnings from postretirement benefit plans - income taxes	(4)	(4)	(7)	(8)
Reclassification of prior service credits into earnings from postretirement benefit plans - income taxes	$ (8)	$ (8)	$ (17)	$ (17)