Employee Benefit Plans (Components Of Net Periodic Benefit Costs) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Sep. 28, 2014	Sep. 29, 2013
Pension Plans and Supplemental Employee Retirement Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 7,874	$ 8,997	$ 23,623	$ 26,990
Interest cost	21,731	19,812	65,193	59,436
Expected return on plan assets	(34,184)	(31,832)	(102,551)	(95,496)
Prior service cost	279	437	838	1,310
Net loss	9,141	14,652	27,422	43,956
Net periodic benefit cost	4,841	12,066	14,525	36,196
Postretirement Healthcare Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,754	1,965	5,262	5,894
Interest cost	4,220	3,900	12,659	11,699
Expected return on plan assets	(2,607)	(2,384)	(7,822)	(7,153)
Prior service cost	(963)	(963)	(2,890)	(2,890)
Net loss	1,182	2,137	3,546	6,412
Net periodic benefit cost	$ 3,586	$ 4,655	$ 10,755	$ 13,962