Pension And Other Postretirement Benefits (Schedule Of Net Benefit Cost Of Pension And Postretirement Benefit Plans) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 25, 2011	Sep. 30, 2012	Sep. 25, 2011
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 696	$ 531	$ 2,085	$ 1,723
Interest cost	4,115	4,387	12,366	12,973
Expected return on Plan assets	(5,043)	(5,160)	(15,128)	(15,003)
Net amortization and deferral	1,604	987	4,814	3,018
Settlement charge			(124)
Curtailment charge			111
Net benefit cost	1,372	745	4,124	2,711
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	159	(37)	475	359
Interest cost	473	441	1,419	1,541
Net amortization and deferral	123	(172)	368	(34)
Net benefit cost	$ 755	$ 232	$ 2,262	$ 1,866