Condensed Consolidated Statements of Comprehensive (Loss)/Earnings (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jul. 01, 2012	Jun. 30, 2013	Jul. 01, 2012
Condensed Consolidated Statements of Comprehensive (Loss)/Earnings [Abstract]
Net (loss)/earnings	$ (11,335)	$ 3,301	$ (7,767)	$ 5,584
Other comprehensive earnings/(loss):
Cumulative translation adjustment, 2013 -net of tax benefit of $71 and net of tax $463; 2012- net of tax of $272 and tax benefit of $64	231	(917)	(1,510)	245
Defined benefit and post-retirement benefit plans:
Amortization of prior service cost included in net periodic pension costs, 2013- net of tax of $59 and $118; 2012- net of tax of $59 and $118	91	92	182	184
Amortization of loss included in net periodic pension costs, 2013- net of tax of $774 and $1,548; 2012- net of tax $600 and $1,206	1,245	982	2,490	1,962
Additional cost due to early retirement, 2013- net of tax of $0 and $0; 2012- net of tax of $110 and $110		171		171
Foreign exchange impact, 2013- net of tax benefit of $2 and net of tax of $72; 2012- net of tax of $33 and tax benefit of $9	(5)	66	202	(48)
Reclassification adjustments included in net earnings - defined benefit and post-retirement benefit plans	1,331	1,311	2,874	2,269
Unrealized gain on interest swaps treated as cash flow hedges:
Unrealized holding gain/(loss) arising during period, 2013-net of tax of $298 and $312; 2012- net of tax benefit of $325 and $325	467	(507)	489	(507)
Reclassification adjustments for losses included in net earnings, 2013- net of tax of $31 and $61; 2012- net of tax of $0 and $0	47		94
Net change in unrealized holding loss on interest rate swaps	514	(507)	583	(507)
Other comprehensive earnings/(loss)	2,076	(113)	1,947	2,007
Comprehensive (loss)/earnings	$ (9,259)	$ 3,188	$ (5,820)	$ 7,591