Employee Benefit Plans (Components Of Net Periodic Benefit Costs) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 29, 2014	Jun. 30, 2013	Jun. 29, 2014	Jun. 30, 2013
Pension Plans and Supplemental Employee Retirement Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 7,874	$ 8,997	$ 15,748	$ 17,994
Interest cost	21,731	19,752	43,462	39,564
Expected return on plan assets	(34,184)	(31,832)	(68,368)	(63,664)
Prior service cost	279	437	558	874
Net loss	9,141	14,652	18,281	29,304
Net periodic benefit cost	4,841	12,006	9,681	24,072
Postretirement Healthcare Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,754	1,965	3,508	3,930
Interest cost	4,220	3,900	8,439	7,800
Expected return on plan assets	(2,607)	(2,384)	(5,215)	(4,768)
Prior service cost	(963)	(963)	(1,927)	(1,926)
Net loss	1,182	2,137	2,364	4,274
Net periodic benefit cost	$ 3,586	$ 4,655	$ 7,169	$ 9,310