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