Pension and Postretirement Benefits (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2014	Mar. 31, 2013
Pension [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 971	$ 1,502
Interest cost	5,058	4,795
Expected return on assets	(5,560)	(5,541)
Net amortization and deferrals	1,252	2,392
Curtailment losses	0	2,959
Net periodic benefit cost	1,721	6,107
Contributions to defined benefit pension plans	1,100
Expected contributions during the remainder of fiscal year	5,300
Postretirement [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	137	188
Interest cost	332	345
Expected return on assets	0	0
Net amortization and deferrals	(113)	(65)
Curtailment losses	0	0
Net periodic benefit cost	$ 356	$ 468