Retirement Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2016	Oct. 03, 2015	Oct. 01, 2016	Oct. 03, 2015
Domestic Plans
Net periodic benefit cost:
Service cost	$ 316	$ 330	$ 947	$ 992
Interest cost	826	805	2,480	2,417
Expected return on assets	(853)	(972)	(2,561)	(2,918)
Prior service costs (credits)	2	2	8	8
Cumulative actuarial net loss (gains)	21	105	62	313
Net periodic benefit cost	312	270	936	812
Foreign Plans
Net periodic benefit cost:
Service cost	634	610	1,897	1,900
Interest cost	788	753	2,356	2,346
Expected return on assets	(852)	(893)	(2,547)	(2,783)
Prior service costs (credits)	5	6	16	17
Cumulative actuarial net loss (gains)	49	57	148	176
Net periodic benefit cost	624	533	1,870	1,656
OPEB Plans
Net periodic benefit cost:
Service cost	3	4	9	10
Interest cost	32	43	95	130
Expected return on assets	0	0	0	0
Prior service costs (credits)	(1)	(1)	(5)	(5)
Cumulative actuarial net loss (gains)	(45)	(4)	(136)	(14)
Net periodic benefit cost	$ (11)	$ 42	$ (37)	$ 121