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		6 Months Ended
	Jul. 01, 2012	Jun. 26, 2011	Jul. 01, 2012	Jun. 26, 2011
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 711	$ 613	$ 1,389	$ 1,192
Interest cost	4,125	4,342	8,251	8,586
Expected return on Plan assets	(5,042)	(4,943)	(10,085)	(9,843)
Net amortization and deferral	1,604	976	3,210	2,031
Settlement charge	(124)		(124)
Curtailment charge	111		111
Net benefit cost	1,385	988	2,752	1,966
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	158	198	316	396
Interest cost	473	549	946	1,100
Net amortization and deferral	122	69	245	138
Net benefit cost	$ 753	$ 816	$ 1,507	$ 1,634