CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS - UNAUDITED (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 29, 2013	Sep. 30, 2012	Sep. 29, 2013	Sep. 30, 2012
Statement Of Income And Comprehensive Income [Abstract]
Net earnings/(loss)	$ 6,819	$ 5,917	$ (948)	$ 11,501
Other comprehensive earnings/(loss):
Cumulative translation adjustment, 2013 -net of tax benefit of $430 and net of tax $32; 2012- net of tax benefit of $444 and $508	1,344	1,371	(166)	1,616
Defined benefit and post-retirement benefit plans:
Amortization of prior service cost included in net periodic pension costs, 2013- net of tax of $53 and $171; 2012- net of tax of $59 and $177	83	93	265	277
Amortization of loss included in net periodic pension costs, 2013- net of tax of $792 and $2,340; 2012- net of tax $612 and $1,818	1,228	964	3,718	2,926
Additional cost due to early retirement, 2013- net of tax of $0 and $0; 2012- net of tax of $0 and $110				171
Foreign exchange impact, 2013- net of tax benefit of $74 and $2; 2012- net of tax benefit of $58 and $67	(139)	(107)	63	(155)
Reclassification adjustments included in net earnings - defined benefit and post-retirement benefit plans	1,172	950	4,046	3,219
Unrealized gain on interest swaps treated as cash flow hedges:
Unrealized holding gain/(loss) arising during period, 2013- net of tax benefit of $168 and net of tax $144; 2012- net of tax benefit of $278 and $603	(260)	(436)	229	(943)
Reclassification adjustments for losses included in net earnings, 2013- net of tax of $31 and $92; 2012- net of tax of $0 and $0	50		144
Net change in unrealized holding loss on interest rate swaps	(210)	(436)	373	(943)
Other comprehensive earnings	2,306	1,885	4,253	3,892
Comprehensive earnings	$ 9,125	$ 7,802	$ 3,305	$ 15,393