Accumulated Other Comprehensive Items, Reclassifications out of AOCI (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 28, 2014		Jun. 29, 2013		Jun. 28, 2014		Jun. 29, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Selling, general, and administrative expenses	$ (31,588)		$ (29,445)		$ (64,070)		$ (56,395)
Interest Expense	(250)		(231)		(556)		(396)
Revenues	104,835		82,165		198,202		158,369
Income from Continuing Operations Before Provision for Income Taxes	11,868		8,336		19,405		15,652
Provision for income taxes	(3,870)		(2,492)		(6,222)		(4,459)
Income from Continuing Operations	7,998		5,844		13,183		11,193
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from Continuing Operations	(377)		(197)		(511)	[1]	(574)	[1]
Pension and Other Post-retirement Plans [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from Continuing Operations Before Provision for Income Taxes	(126)	[2]	(172)	[2]	(249)	[2]	(379)	[2]
Provision for income taxes	44	[2]	59	[2]	87	[2]	131	[2]
Income from Continuing Operations	(82)	[2]	(113)	[2]	(162)	[2]	(248)	[2]
Amortization of Prior Service Cost [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Selling, general, and administrative expenses	(38)	[2]	(35)	[2]	(73)	[2]	(70)	[2]
Amortization of Actuarial Losses [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Selling, general, and administrative expenses	(88)	[2]	(137)	[2]	(176)	[2]	(309)	[2]
Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from Continuing Operations Before Provision for Income Taxes	(362)	[1]	(130)	[1]	(446)	[1]	(279)	[1]
Provision for income taxes	67	[1]	46	[1]	97	[1]	(47)	[1]
Income from Continuing Operations	(295)	[1]	(84)	[1]	(349)	[1]	(326)	[1]
Cash Flow Hedges [Member] | Interest Rate Swap [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest Expense	(84)	[1]	(90)	[1]	(168)	[1]	(196)	[1]
Cash Flow Hedges [Member] | Forward Currency-Exchange Contracts [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Selling, general, and administrative expenses	(278)	[1]	0	[1]	(278)	[1]	0	[1]
Revenues	$ 0	[1]	$ (40)	[1]	$ 0	[1]	$ (83)	[1]

[1] See Note 10 for additional information.

[2] Included in the computation of net periodic benefit costs. See Note 8 for additional information.