Retirement Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2015	Sep. 27, 2014	Oct. 03, 2015	Sep. 27, 2014
Domestic Plans
Net periodic benefit cost:
Service cost	$ 330	$ 322	$ 992	$ 967
Interest cost	805	788	2,417	2,364
Expected return on plan assets	(972)	(1,017)	(2,918)	(3,053)
Prior service cost	2	3	8	9
Cumulative actuarial net loss	105	0	313	0
Net periodic benefit cost	270	96	812	287
Foreign Plans
Net periodic benefit cost:
Service cost	610	597	1,900	1,794
Interest cost	753	911	2,346	2,738
Expected return on plan assets	(893)	(1,079)	(2,783)	(3,243)
Prior service cost	6	4	17	14
Cumulative actuarial net loss	57	14	176	42
Net periodic benefit cost	533	447	1,656	1,345
OPEB Plans
Net periodic benefit cost:
Service cost	4	4	10	10
Interest cost	43	49	130	147
Expected return on plan assets	0	0	0	0
Prior service cost	(1)	(2)	(5)	(6)
Cumulative actuarial net loss	(4)	(11)	(14)	(33)
Net periodic benefit cost	$ 42	$ 40	$ 121	$ 118