Retirement Plans (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jul. 02, 2011	Jun. 30, 2012	Jul. 02, 2011
Components of the net periodic expense of pension and other post retirement plans [Line Items]
Service cost	$ 517,000	$ 369,000	$ 1,034,000	$ 657,000
Interest cost	3,633,000	3,773,000	7,266,000	7,543,000
Expected return on plan assets	(4,258,000)	(4,092,000)	(8,516,000)	(8,181,000)
Net amortization and deferral	(1,000)	(1,000)	(2,000)	(2,000)
Recognized net actuarial loss	1,628,000	316,000	3,256,000	632,000
Net periodic expense	1,519,000	365,000	3,038,000	649,000
Pension and Other Postretirement Benefit Contributions [Abstract]
Company Contributions			8,800,000
Estimated Future Company Contributions in Current Fiscal Year	10,600,000		10,600,000
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	$ 400,000	$ 400,000