Retirement Plans (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 29, 2012	Oct. 01, 2011	Sep. 29, 2012	Oct. 01, 2011
Components of the net periodic expense of pension and other post retirement plans [Line Items]
Service cost	$ 415,000	$ 440,000	$ 1,449,000	$ 1,097,000
Interest cost	3,642,000	3,722,000	10,908,000	11,265,000
Expected return on plan assets	(4,141,000)	(4,094,000)	(12,657,000)	(12,275,000)
Net amortization and deferral	(1,000)	(2,000)	(3,000)	(4,000)
Recognized net actuarial loss	1,562,000	190,000	4,818,000	822,000
Net periodic expense	1,477,000	256,000	4,515,000	905,000
Pension and Other Postretirement Benefit Contributions [Abstract]
Company Contributions			15,700,000
Estimated Future Company Contributions in Current Fiscal Year	2,700,000		2,700,000
Other Postretirement Benefit Plans, Defined Benefit [Member]
Components of the net periodic expense of pension and other post retirement plans [Line Items]
Interest cost	$ 200,000	$ 200,000	$ 700,000	$ 600,000