Employee Benefit Plans (Components Of Net Periodic Benefit Costs) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 29, 2014
Pension Plans and Supplemental Employee Retirement Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 10,010	$ 7,874	$ 20,020	$ 15,748
Interest cost	21,836	21,731	43,672	43,462
Expected return on plan assets	(36,232)	(34,184)	(72,465)	(68,368)
Prior service cost	109	279	218	558
Net loss	13,677	9,141	27,354	18,281
Net periodic benefit cost	9,400	4,841	18,799	9,681
Postretirement Healthcare Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2,065	1,754	4,130	3,508
Interest cost	3,541	4,220	7,082	8,439
Expected return on plan assets	(2,877)	(2,607)	(5,754)	(5,215)
Prior service cost	(804)	(963)	(1,608)	(1,927)
Net loss	993	1,182	1,986	2,364
Net periodic benefit cost	$ 2,918	$ 3,586	$ 5,836	$ 7,169