Other Comprehensive Income (Loss) (Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated other comprehensive loss - interest rate swaps	$ (144)	$ (654)	$ (565)
Accumulated other comprehensive - postretirement liabilities	360	416	477
Accumulated other comprehensive loss - total	216	(238)	(88)
Unrealized gain (loss) on interest rate swaps	(1,928)	236	(476)
Reclassification of loss into earnings from interest rate swaps	231	176	98
Amortization of unrealized loss on dedesignated interest rate swaps	0	98	289
Unrecognized net actuarial gain on postretirement benefit plans	41	20	20
Reclassification of net actuarial gain into earnings from postretirement benefit plans	(19)	(22)	(27)
Reclassification of prior service credits into earnings from postretirement benefit plans	(54)	(54)	(54)
Accumulated other comprehensive loss - interest rate swaps	(1,841)	(144)	(654)
Accumulated other comprehensive - postretirement liabilities	328	360	416
Accumulated other comprehensive loss - total	(1,513)	216	(238)
Unrealized gain (loss) on interest rate swaps - income taxes	(1,182)	145	(291)
Reclassification of loss into earnings from interest rate swaps - income taxes	141	108	60
Amortization of unrealized loss on dedesignated interest rate swap - income taxes	0	60	178
Unrecognized net actuarial gain on postretirement plans - income taxes	26	12	13
Reclassification of net actuarial gain into earnings from postretirement benefit plans - income taxes	(12)	(13)	(18)
Reclassification of prior service credits into earnings from postretirement benefit plans - income taxes	$ (34)	$ (34)	$ (34)