Pension and Postretirement Benefits (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Apr. 01, 2012
Pension [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 1,502	$ 1,198
Interest cost	4,795	5,494
Expected return on assets	(5,541)	(5,671)
Net amortization and deferrals	2,392	1,908
Curtailment loss	2,959	0
Net periodic benefit cost	6,107	2,929
Contributions to defined benefit pension plans	1,600
Expected contributions during the remainder of fiscal year	4,200
Postretirement [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	188	184
Interest cost	345	440
Expected return on assets	0	0
Net amortization and deferrals	(65)	20
Curtailment loss	0	0
Net periodic benefit cost	$ 468	$ 644