Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2015	Sep. 27, 2014	Oct. 03, 2015	Sep. 27, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 8,174	$ 9,657	$ 20,578	$ 19,692
Components of other comprehensive income/(loss), net of tax:
Foreign currency translation adjustments	(1,561)	(1,263)	(3,828)	(1,266)
Amortization of defined benefit pension items:
Net actuarial loss	213	109	668	329
Prior service cost	1	3	3	7
Defined benefit pension plan adjustments	214	112	671	336
Other comprehensive income/(loss), net of tax	(1,347)	(1,151)	(3,157)	(930)
Comprehensive income	$ 6,827	$ 8,506	$ 17,421	$ 18,762