Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 29, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Balance, beginning of period	$ (115,547)	$ (149,798)	$ (116,882)
Other comprehensive income (loss) before reclassifications	175	194	(166)	$ 79
Amounts reclassified from accumulated other comprehensive income (loss)	1,675	1,800	3,351	3,600
Balance, end of period	(113,697)	(147,804)	(113,697)	(147,804)
Foreign Currency [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Balance, beginning of period	(175)	472	166
Other comprehensive income (loss) before reclassifications	175	194	(166)	79
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0	0
Balance, end of period	0	666	0	666
Defined Benefit Pension Plan [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Balance, beginning of period	(115,372)	(150,270)	(117,048)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	1,675	1,800	3,351	3,600
Balance, end of period	$ (113,697)	$ (148,470)	$ (113,697)	$ (148,470)