Pension and Other Postretirement Benefits (Details) (USD $)	3 Months Ended
	Mar. 30, 2014	Mar. 31, 2013
Net periodic benefit cost/(income)
Estimated future contributions to pension plans based on contractual obligations for the remaining fiscal year	$ 16,000,000
Estimated increase in liability due to new guidance	150,000,000
Estimated increase in expense due to new guidance	10,000,000
Qualified Plans [Member]
Net periodic benefit cost/(income)
Service cost	2,386,000	2,323,000
Interest cost	21,112,000	19,284,000
Expected return on plan assets	(28,460,000)	(31,063,000)
Amortization of prior service credit	(486,000)	(486,000)
Amortization of actuarial loss	6,598,000	8,442,000
Net periodic benefit cost/(income)	1,150,000	(1,500,000)
Contributions to certain qualified pension plans	4,000,000
Non-Qualified Plans [Member]
Net periodic benefit cost/(income)
Service cost	1,000	256,000
Interest cost	2,875,000	2,643,000
Expected return on plan assets	0	0
Amortization of prior service credit	0	0
Amortization of actuarial loss	1,054,000	1,312,000
Net periodic benefit cost/(income)	3,930,000	4,211,000
Pension Plans, Defined Benefit [Member]
Net periodic benefit cost/(income)
Service cost	2,387,000	2,579,000
Interest cost	23,987,000	21,927,000
Expected return on plan assets	(28,460,000)	(31,063,000)
Amortization of prior service credit	(486,000)	(486,000)
Amortization of actuarial loss	7,652,000	9,754,000
Net periodic benefit cost/(income)	5,080,000	2,711,000
Other Postretirement Benefit Plan, Defined Benefit [Member]
Net periodic benefit cost/(income)
Service cost	147,000	285,000
Interest cost	1,010,000	1,009,000
Amortization of prior service credit	(1,600,000)	(3,693,000)
Amortization of actuarial loss	1,184,000	1,022,000
Net periodic benefit cost/(income)	$ 741,000	$ (1,377,000)