Pension and Postretirement Benefit Plans Net Periodic Benefit (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year			$ 5,000
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	$ 0	$ (29)	0	$ (125)
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	874	835	1,747	1,679
Interest cost	2,463	1,379	4,921	2,770
Expected return on plan assets	(3,122)	(1,864)	(6,240)	(3,748)
Curtailment / settlement (gain) loss	0	0	0	0
Defined Benefit Plan, Actuarial Gain (Loss)	(4)	87	(8)	175
Transition costs and other	0	0	0	0
Net periodic benefit cost	211	437	420
United States Pension Plan of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost				876
Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	9	15	18	30
Interest cost	94	46	187	92
Curtailment / settlement (gain) loss	0	0	0	0
Defined Benefit Plan, Actuarial Gain (Loss)	5	9	10	18
Transition costs and other	0	0	0	0
Net periodic benefit cost	108	70
United States Postretirement Benefit Plan of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost			215	140
Maximum
Defined Benefit Plan Disclosure [Line Items]
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	$ 100	$ (96)	$ 100	$ 200