Other Comprehensive Income (Loss) (Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jul. 02, 2011	Jun. 30, 2012	Jul. 02, 2011
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated other comprehensive loss - interest rate swaps			$ (565)
Accumulated other comprehensive - postretirement liabilities			477
Accumulated other comprehensive loss - total			(88)
Unrealized gain (loss) on interest rate swaps	(241)	(161)	(321)	(132)
Reclassification of loss into earnings from interest rate swaps	24	85	48	172
Amortization of unrealized losses on dedesignated interest rate swaps	73	0	147	0
Reclassification of net actuarial gain into earnings from postretirement benefit plans	(6)	(4)	(12)	(9)
Reclassification of prior service credits into earnings from postretirement benefit plans	(14)	(14)	(28)	(28)
Accumulated other comprehensive loss - interest rate swaps	(691)		(691)
Accumulated other comprehensive - postretirement liabilities	437		437
Accumulated other comprehensive loss - total	(254)		(254)
Unrealized gain (loss) on interest rate swaps - income taxes	(147)	(98)	(197)	(81)
Reclassification of loss into earnings from interest rate swaps - income taxes	15	52	29	105
Amortization of unrealized loss on dedesignated interest rate swap - income taxes	44	0	89	0
Reclassification of net actuarial gain into earnings from postretirement benefit plans - income taxes	(3)	(3)	(7)	(6)
Reclassification of prior service credits into earnings from postretirement benefit plans - income taxes	$ 8	$ 8	$ 16	$ 17