Employee Benefit Plans (Components Of Net Periodic Benefit Costs) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jul. 01, 2012	Jun. 30, 2013	Jul. 01, 2012
Pension And SERPA Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 8,997	$ 8,420	$ 17,994	$ 16,840
Interest cost	19,752	20,816	39,564	41,632
Expected return on plan assets	(31,832)	(29,277)	(63,664)	(58,555)
Prior service cost	437	740	874	1,479
Net loss	14,652	10,969	29,304	21,937
Net periodic benefit cost	12,006	11,668	24,072	23,333
Postretirement Healthcare Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,965	1,853	3,930	3,706
Interest cost	3,900	4,578	7,800	9,155
Expected return on plan assets	(2,384)	(2,356)	(4,768)	(4,712)
Prior service cost	(963)	(963)	(1,926)	(1,927)
Net loss	2,137	1,855	4,274	3,711
Net periodic benefit cost	$ 4,655	$ 4,967	$ 9,310	$ 9,933