Net Periodic Benefit Cost - Defined Benefit Pension Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 04, 2015	Jun. 28, 2014	Jul. 04, 2015	Jun. 28, 2014
Defined Benefit Plan Disclosure [Line Items]
Curtailment cost	$ 49
Pension plans, defined benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service costs--increase in benefit obligation earned	5	$ 13	$ 26	$ 26
Interest cost on projected benefit obligation	376	405	755	809
Expected return on plan assets	(406)	(498)	(811)	(996)
Curtailment cost	49	0	49	0
Amortization of net actuarial loss	346	177	733	354
Amortization of prior service cost	1	3	4	6
Net pension cost of defined benefit pension plans	$ 371	$ 100	$ 756	$ 199