Retirement Plans - (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
Domestic Plans
Net periodic benefit cost:
Service cost	$ 322	$ 239	$ 967	$ 774
Interest cost	788	735	2,364	2,177
Expected return on plan assets	(1,017)	(887)	(3,053)	(2,661)
Net periodic benefit cost	96	169	287	470
Prior service cost	3	0	9	0
Cumulative actuarial net loss	0	82	0	180
Foreign Plans
Net periodic benefit cost:
Service cost	597	698	1,794	2,119
Interest cost	911	937	2,738	2,844
Expected return on plan assets	(1,079)	(970)	(3,243)	(2,946)
Net periodic benefit cost	447	800	1,345	2,426
Prior service cost	4	5	14	15
Cumulative actuarial net loss	14	130	42	394
OPEB Plans
Net periodic benefit cost:
Service cost	4	2	10	9
Interest cost	49	39	147	138
Expected return on plan assets	0	0	0	0
Net periodic benefit cost	40	31	118	141
Prior service cost	(2)	0	(6)	0
Cumulative actuarial net loss	$ (11)	$ (10)	$ (33)	$ (6)